2024/02/20 更新

写真a

タケオカ シンジ
武岡 真司
所属
理工学術院 先進理工学部
職名
教授
学位
工学博士 ( 早稲田大学 )

経歴

  • 2007年04月
    -
    継続中

    早稲田大学   理工学術院   教授

  • 2005年04月
    -
    2007年03月

    早稲田大学   理工学部   教授

  • 1996年04月
    -
    2005年03月

    早稲田大学   理工学部   助教授

  • 1993年
    -
    1996年

    早稲田大学   理工学部   専任講師

  • 1991年04月
    -
    1993年03月

    早稲田大学   理工学部   助手

  • 1990年
    -
    1991年

    日本学術振興会 特別研究員

▼全件表示

学歴

  •  
    -
    1991年

    早稲田大学   理工学研究科   応用化学専攻  

  •  
    -
    1986年

    早稲田大学   理工学部   応用化学  

所属学協会

  •  
     
     

    日本バイオマテリアル学会

  •  
     
     

    日本DDS学会

  •  
     
     

    日本人工臓器学会

  •  
     
     

    米国化学会

  •  
     
     

    日本化学会

  •  
     
     

    日本血液代替物学会

  •  
     
     

    高分子学会

▼全件表示

研究分野

  • その他   医療レギュラトリーサイエンス / ナノマイクロシステム / 複合材料、界面 / 薄膜、表面界面物性 / ナノバイオサイエンス / 生体材料学 / 生体医工学

研究キーワード

  • 薬物運搬体、創傷被覆材、人工血液、皮膚電極、薄膜型センサー

  • バイオマテリアル、ナノバイオマテリアル、バイオメディカルエンジニアリング

  • 機能・物性・材料、高分子構造・物性(含繊維)、高分子合成、高分子(分子集合体)の構造・物性

受賞

  • 大隈記念学術褒章(奨励賞)

    2011年10月  

 

論文

  • Early treatment with Fibrinogen γ-chain peptide-coated, ADP-encapsulated Liposomes (H12-(ADP)-liposomes) ameliorates post-partum hemorrhage with coagulopathy caused by amniotic fluid embolism in rabbits

    Koki Kaneko, Kohsuke Hagisawa, Manabu Kinoshita, Yuka Ohtsuka, Ruka Sasa, Morihiro Hotta, Daizoh Saitoh, Kimiya Sato, Shinji Takeoka, Katsuo Terui

    AJOG Global Reports   3 ( 4 ) 100280 - 100280  2023年11月

    DOI

    Scopus

  • Evaluation of a static mixer as a new microfluidic method for liposome formulation

    Aoba Ota, Ayaka Mochizuki, Keitaro Sou, Shinji Takeoka

    Frontiers in Bioengineering and Biotechnology   11  2023年08月

     概要を見る

    Introduction: Microfluidic formulation of liposomes has been extensively studied as a potential replacement for batch methods, which struggle with problems in scalability and difficulty in modulating conditions. Although microfluidic devices are considered to be able to combat these issues, an adequate replacement method has yet to be established.

    Methods: This paper examines the potential of a static mixer (SM) by comparing the encapsulation efficiency, loading, lamellarity, and user-friendliness with a commonly used microfluidic device, a staggered herringbone micromixer (SHM).

    Results: In both devices, it was found that as the initial lipid concentration increased, the particle size increased; however, the overall particle size was seen to be significantly larger in the liposomes prepared with SM. PDI remained significantly smaller in SM, however, signifying that better control of the particle size was accomplished in SM. In addition, the encapsulation efficiency was slightly smaller in SM compared to SHM, and in both devices, the values increased as the initial lipid concentration increased. The increase in encapsulation efficiencies was significantly smaller than that of the theoretical encapsulation efficiency, and this was found to be due to the increase in lamellarity as the initial lipid concentration increased.

    Discussion: In terms of user-friendliness, SM demonstrated significant advantages. The mixing elements could be taken out from the device, allowing for thorough cleaning of the element and device before and after experiments and ensuring experiments are conducted at virgin state in every round. Consequently, it was found that SM not only can produce uniformly distributed liposomes but has the potential to become a more practical method for liposome formulation with modifications in the mixing elements.

    DOI

    Scopus

  • In vitro study on the effect of fibrinogen γ-chain peptide-coated ADP-encapsulated liposomes on postcardiopulmonary bypass coagulopathy using patient blood

    Osamu Ishida, Kohsuke Hagisawa, Nozomu Yamanaka, Hiroyuki Nakashima, Bradley M. Kearney, Koji Tsutsumi, Shinji Takeoka, Manabu Kinoshita

    Journal of Thrombosis and Haemostasis   21 ( 7 ) 1934 - 1942  2023年07月

     概要を見る

    Background: Fibrinogen γ-chain peptide-coated, adenosine 5'-diphosphate (ADP)-encapsulated liposomes (H12-ADP-liposomes) are potent hemostatic adjuvants that promote platelet thrombi formation at bleeding sites. Although we have reported the efficacy of these liposomes in a rabbit model of cardiopulmonary bypass coagulopathy, we are yet to address the possibility of their hypercoagulative potential, especially in human beings. Objectives: Considering its future clinical applications, we herein investigated the safety of using H12-ADP-liposomes in vitro using blood samples from patients who had received platelet transfusion after cardiopulmonary bypass surgeries. Methods: Ten patients receiving platelet transfusions after cardiopulmonary bypass surgery were enrolled. Blood samples were collected at the following 3 points: at the time of incision, at the end of the cardiopulmonary bypass, and immediately after platelet transfusion. After incubating the samples with H12-ADP-liposomes or phosphate-buffered saline (PBS, as a control), blood coagulation, platelet activation, and platelet-leukocyte aggregate formation were evaluated. Results: Patients’ blood incubated with H12-ADP-liposomes did not differ from that incubated with PBS in coagulation ability, degree of platelet activation, and platelet-leukocyte aggregation at any of the time points. Conclusion: H12-ADP-liposomes did not cause abnormal coagulation, platelet activation, or platelet-leukocyte aggregation in the blood of patients who received platelet transfusion after a cardiopulmonary bypass. These results suggest that H12-ADP-liposomes could likely be safely used in these patients, providing hemostasis at the bleeding sites without causing considerable adverse reactions. Future studies are needed to ensure robust safety in human beings.

    DOI PubMed

    Scopus

    1
    被引用数
    (Scopus)
  • Development of the observation of membrane fusion with label-free liposomes by calcium imaging

    Morihiro Hotta, Kengo Hayase, Aya Kitanaka, Tianshu Li, Shinji Takeoka

    Biochemistry and Biophysics Reports   34   101483 - 101483  2023年07月

    DOI

    Scopus

  • Do Ultrafine Bubbles Work as Oxygen Carriers?

    Kenta Kakiuchi, Tomoki Kozuka, Nobuyuki Mase, Takehiro Miyasaka, Norikazu Harii, Shinji Takeoka

    Langmuir : the ACS journal of surfaces and colloids   39 ( 4 ) 1354 - 1363  2023年01月  [国際誌]

     概要を見る

    Fine bubbles (FBs) are bubbles with sizes less than 100 μm and are divided into ultrafine bubbles (UFBs, < 1 μm) and microbubbles (MBs, 1-100 μm) depending on their size. Although FB aeration is known as a more efficient way than macrobubble aeration to increase the oxygen level in unoxygenated water, few reports have demonstrated whether dispersed UFBs work as oxygen carriers or not. Furthermore, oxygen supersaturation is one of the attractive characteristics of FB dispersion, but the reason is yet to be revealed. In this study, we evaluated the relationship between the FBs, especially UFB concentration, and oxygen content in several situations to reveal the two questions. The FB concentration and oxygen content were examined using particle analyzers and our developed oxygen measurement method, which can measure the oxygen content in FB dispersion, respectively. First, in the evaluations of the oxygen dispersion from UFBs with respect to the surrounding oxygen level, UFBs did become neither small nor diminish even in degassed water. Second, the changes in UFBs and oxygen content upon storage temperature and the existence of a lid during storage were evaluated, and there was no correlation between them. It means UFBs contribute little to the oxygen content in UFB dispersion. Furthermore, the oxygen content in the UFB dispersion decreased over time identically as that of the oxygen-supersaturated water with little UFBs. Third, we evaluated the relationship between FB concentration and oxygen content during FB generation by measuring them simultaneously. The results showed that dispersed MB and UFB concentrations did not account for the supersaturation of the FB dispersion. From the result, it was revealed that 100-200 nm of UFBs themselves did not work as oxygen carriers, and the oxygen supersaturation in FB dispersions was due to the supersaturated state of dissolved oxygen that was prepared during the FB generation process.

    DOI PubMed

    Scopus

    1
    被引用数
    (Scopus)
  • Temperature-Responsive Liposome-Linked Immunosorbent Assay for the Rapid Detection of SARS-CoV-2 Using Immunoliposomes.

    Runkai Hu, Morihiro Hotta, Taro Maruyama, Mizuki Fujisawa, Keitaro Sou, Shinji Takeoka

    ACS omega   7 ( 30 ) 26936 - 26944  2022年08月  [国際誌]

     概要を見る

    Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is the etiological agent of coronavirus disease 2019 (COVID-19), has infected more than 340 million people since the outbreak of the pandemic in 2019, resulting in approximately 55 million deaths. The rapid and effective diagnosis of COVID-19 patients is vital to prevent the spread of the disease. In a previous study, we reported a novel temperature-responsive liposome-linked immunosorbent assay (TLip-LISA) using biotinylated-TLip that exhibited high detection sensitivity for the prostate-specific antigen. Herein, we used immunoglobulin-TLip (IgG-TLip), in which the antibodies were directly conjugated to the liposomal surface to simplify pretreatment procedures and reduce the detection time for SARS-CoV-2. The results indicated that TLip-LISA could detect the recombinant nucleocapsid protein and the nucleocapsid protein in inactivated virus with 20 min incubation time in total, and the limit of detection was calculated to be 2.2 and 1.0 pg/mL, respectively. Therefore, TLip-LISA has high potential to be used in clinic for rapid diagnosis and disease control.

    DOI PubMed

    Scopus

    3
    被引用数
    (Scopus)
  • Paper-Based Wearable Ammonia Gas Sensor Using Organic–Inorganic Composite PEDOT:PSS with Iron(III) Compounds

    Hajime Fujita, Meiting Hao, Shinji Takeoka, Yuji Miyahara, Tatsuro Goda, Toshinori Fujie

    Advanced Materials Technologies   7 ( 8 )  2022年08月

     概要を見る

    Paper electronics are expected to be a game-changer in next-generation flexible electronics that could replace conventional plastic electronics. Paper electronics are disposable and cost-effective, two distinct advantages for the development of broadly accessible devices, but their poor performance has limited their practical implementation so far. Here, a high-sensitivity, high-performance, paper-based, wearable ammonia sensor comprising composite poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and iron(III) compounds is reported. The sensor achieves 10-times smaller size than the conventional sensor on Kapton film and high tolerance for humidity without losing practical sensor response. The utility of the device is demonstrated for wearable ammonia sensing in a facial mask and a nasal filter; wireless monitoring of food spoilage; and wireless monitoring of the ammonia level in a diaper. The approach of this study may open the door to advanced healthcare based on ubiquitous wearable sensing.

    DOI

    Scopus

    11
    被引用数
    (Scopus)
  • Arginine-based cationic liposomes accelerate T cell activation and differentiation in vitro

    Tianshu Li, Felix Tolksdorf, Wenhan Sung, Hiroto Sato, Felix J. Eppler, Morihiro Hotta, Waldemar Kolanus, Shinji Takeoka

    International Journal of Pharmaceutics     121917 - 121917  2022年06月

    DOI

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    1
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  • H12-(ADP)-liposomes for hemorrhagic shock in thrombocytopenia: Mesenteric artery injury model in rabbits.

    Kohsuke Hagisawa, Manabu Kinoshita, Shinji Takeoka, Osamu Ishida, Yayoi Ichiki, Daizoh Saitoh, Morihiro Hotta, Masato Takikawa, Ivo P Torres Filho, Yuji Morimoto

    Research and practice in thrombosis and haemostasis   6 ( 2 ) e12659  2022年02月  [国際誌]

     概要を見る

    Background: Damage control resuscitation improves patient outcomes after severe hemorrhage and coagulopathy. However, effective hemostasis methods for these critical situations are lacking. Objective: We evaluated the hemostatic efficacy of fibrinogen γ-chain (HHLGGAKQAGDV, H12)-coated, adenosine-diphosphate (ADP)-encapsulated liposomes (H12-[ADP]-liposomes) in thrombocytopenic rabbits with hemorrhagic shock. Methods: Acute thrombocytopenia (80%) was induced in rabbits that also received mesenteric vessel injury, leading to hemorrhagic shock. Five minutes after injury, subjects received intravenous bolus injection with H12-(ADP)-liposomes (20 mg/kg), followed by isovolemic transfusion with stored red blood cells (RBCs)/platelet poor plasma (PPP) (RBC:PPP = 1:1 [vol/vol]), or lactated Ringer solution every 5 min to compensate blood loss. One group received H12-(phosphate buffered saline [PBS]) liposomes followed by RBC/PPP. Additional groups were received isovolemic transfusion with RBC/platelet rich plasma (PRP) (RBC:PRP = 1:1 [vol/vol]), RBC/PPP, PPP alone, or lactated Ringer solution. Results: Treatment with H12-(ADP)-liposomes followed by RBC/PPP transfusion and RBC/PRP transfusion effectively stopped bleeding in all thrombocytopenic rabbits. In contrast, three of 10 rabbits treated with RBC/PPP failed hemostasis, and no rabbits receiving lactated Ringer solution stopped bleeding or survived. Twenty-four hours after hemorrhage, 80% of rabbits receiving H12-(ADP)-liposome followed by RBC/PPP transfusion survived and 70% of rabbits receiving RBC/PRP transfusion also survived, although RBC/PPP-transfused rabbits showed 40% survival. Rabbits receiving H12-(ADP)-liposomes followed by lactated Ringer solution showed a transient hemostatic potential but failed to survive. H12-(PBS)-liposomes showed no beneficial effect on hemostasis. Neither the PPP group nor the lactated Ringer group survived. Conclusion: H12-(ADP)-liposome treatment followed by RBC/PPP may be effective in lethal hemorrhage after mesenteric vessel injury in coagulopathic rabbits.

    DOI PubMed

    Scopus

    3
    被引用数
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  • Development of quantitative and concise measurement method of oxygen in fine bubble dispersion.

    Kenta Kakiuchi, Takehiro Miyasaka, Norikazu Harii, Shinji Takeoka

    PloS one   17 ( 2 ) e0264083  2022年  [国際誌]

     概要を見る

    Fine bubbles (FBs) have attracted significant attention in several research fields. Although some reports have argued that FB dispersion is useful as an oxygen (gas) carrier, only a few reports have examined its properties as an oxygen carrier using experimental data. As one of the reasons for this, there are no standard methods for measuring the oxygen content in FB dispersions. Conventional oxygen measurement methods have certain drawbacks in accuracy or speed; thus, it is difficult to use oxygen content as the primary outcome. In this study, we introduce a Clark-type polarographic oxygen electrode device (OXYG1-PLUS) for oxygen measurement, allowing the dilution of FB dispersion without the influence of ambient air and the adhesion of FBs on the electrode surface due to its special shape. First, the accuracy of our dilution method was evaluated using pure water as a sample, and it was confirmed that our method could measure with an accuracy of ±0.5 mg/L from the results with conventional dissolved oxygen meters. Second, the oxygen content in FB dispersion was evaluated with our method and a chemical titration method (Winkler's method), and it was found that our method could measure the oxygen content in FB dispersions quantitively. This method satisfies the easiness (4 steps) and quickness (within 8 min) for a wide range of oxygen contents (0 to 332 mg/L, theoretical range) with low coefficient variation (< 4.7%) and requires a small sample volume (50-500 μL); thus, it is a useful method for measuring the oxygen in FB dispersions.

    DOI PubMed

    Scopus

    2
    被引用数
    (Scopus)
  • Flexible Film-Type Sensor for Electrochemical Measurement of Dopamine Using a Molecular Imprinting Method

    Takumi Kishi, Toshinori Fujie, Hiroyuki Ohta, Shinji Takeoka

    Frontiers in Sensors   2  2021年10月  [査読有り]

    DOI

  • Enhanced cellular engraftment of adipose-derived mesenchymal stem cell spheroids by using nanosheets as scaffolds.

    Hisato Nagano, Yoshitaka Suematsu, Megumi Takuma, Shimpo Aoki, Ayano Satoh, Eiji Takayama, Manabu Kinoshita, Yuji Morimoto, Shinji Takeoka, Toshinori Fujie, Tomoharu Kiyosawa

    Scientific reports   11 ( 1 ) 14500 - 14500  2021年07月  [国際誌]

     概要を見る

    The short survival time of transplanted adipose-derived mesenchymal stem cells (ASCs) is a problem for skin wound healing. Transplantation after the formation of cellular spheroids has been investigated as a promising method for prolonging cellular survival. However, there have been technical restrictions for transplantation of spheroids in clinical practice. Here, we show an effective method for transplantation of ASC spheroids onto skin wounds in order to efficiently cure refractory ulcers. To assist anchoring of spheroids onto skin wounds, we used a 120-nm-thick free-standing film (nanosheet) that has a highly adhesive property. Bioluminescence imaging showed that ASC spheroids carried by the nanosheet survived for 14 days, which is about two-times longer than that previously reported. Wounds treated with a nanosheet carrying ASC spheroids were 4-times smaller than untreated wounds on day 14. This method for transplantation of spheroids could be applied to cell therapy for various refractory skin wounds.

    DOI PubMed

    Scopus

    13
    被引用数
    (Scopus)
  • Ultra-Thin Porous PDLLA Films Promote Generation, Maintenance, and Viability of Stem Cell Spheroids

    Ya An Tsai, Tianshu Li, Lucia A. Torres-Fernández, Stefan C. Weise, Waldemar Kolanus, Shinji Takeoka

    Frontiers in Bioengineering and Biotechnology   9  2021年06月

     概要を見る

    Three-dimensional (3D) culture bridges and minimizes the gap between <italic>in vitro</italic> and <italic>in vivo</italic> states of cells and various 3D culture systems have been developed according to different approaches. However, most of these approaches are either complicated to operate, or costive to scale up. Therefore, a simple method for stem cell spheroid formation and preservation was proposed using poly(D,<sc>L</sc>-lactic acid) porous thin film (porous nanosheet), which were fabricated by a roll-to-roll gravure coating method combining a solvent etching process. The obtained porous nanosheet was less than 200 nm in thickness and had an average pore area of 6.6 μm2 with a porosity of 0.887. It offered a semi-adhesive surface for stem cells to form spheroids and maintained the average spheroid diameter below 100 μm for 5 days. In comparison to the spheroids formed in suspension culture, the porous nanosheets improved cell viability and cell division rate, suggesting the better feasibility to be applied as 3D culture scaffolds.

    DOI

  • Artificial blood transfusion: A new chapter in an old story

    K. Hagisawa, M. Kinoshita, H. Sakai, S. Takeoka

    Physiology News   Spring ( Spring 2021 ) 22 - 25  2021年  [招待有り]

    DOI

  • Metronomic photodynamic therapy using an implantable LED device and orally administered 5-aminolevulinic acid

    Izumi Kirino, Katsuhiko Fujita, Kei Sakanoue, Rin Sugita, Kento Yamagishi, Shinji Takeoka, Toshinori Fujie, Shinji Uemoto, Yuji Morimoto

    Scientific Reports   10 ( 1 ) 22017 - 22017  2020年12月  [国際誌]

     概要を見る

    <jats:title>Abstract</jats:title><jats:p>Metronomic photodynamic therapy (mPDT) is a form of PDT that induces cancer cell death by intermittent continuous irradiation with a relatively weak power of light for a long duration (several days). We previously developed a wirelessly powered, fully implantable LED device and reported a significant anti-tumor effect of mPDT. Considering application in clinical practice, the method used for repeated administrations of photosensitizers required for mPDT should not have a high patient burden such as the burden of transvenous administration. Therefore, in this study, we selected 5-aminolevulinic acid (ALA), which can be administered orally, as a photosensitizer, and we studied the antitumor effects of mPDT. In mice with intradermal tumors that were orally administered ALA (200 mg/kg daily for 5 days), the tumor in each mouse was simultaneously irradiated (8 h/day for 5 days) using a wirelessly powered implantable green LED device (532 nm, 0.05 mW). Tumor growth in the mPDT-treated mice was suppressed by about half compared to that in untreated mice. The results showed that mPDT using the wirelessly powered implantable LED device exerted an antitumor effect even with the use of orally administered ALA, and this treatment scheme can reduce the burden of photosensitizer administration for a patient.</jats:p>

    DOI PubMed

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    24
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  • Total alveolar lavage with oxygen fine bubble dispersion directly improves lipopolysaccharide-induced acute respiratory distress syndrome of rats

    Kenta Kakiuchi, Takehiro Miyasaka, Shinji Takeoka, Kenichi Matsuda, Norikazu Harii

    Scientific Reports   10 ( 1 )  2020年12月

     概要を見る

    <title>Abstract</title>
    Severe respiratory disorder induced by pulmonary inflammation is one of the causes of acute respiratory distress syndrome, which still has high mortality. It is crucial to remove causative substances and inflammatory mediators early in order to inhibit the progression of pulmonary inflammation. Total alveolar lavage (TAL) may avert the inflammatory response by eliminating causative substances in certain inflammatory lung diseases. We developed an efficient TAL system and examined the efficacy of short-term TAL treatment performed for acute lung injury models of rats. In the first experiment with a severe lung injury model, 15 rats were divided into 3 groups: sham group, mechanical gas ventilation (MGV) treatment group, and TAL treatment group. The treatments were conducted for 5 min, 20 min after the provocation of inflammation. Two days after treatment, the TAL and MGV treatment groups exhibited significant differences in blood oxygen levels, mean arterial pressure, weight-loss ratio, and inflammatory cytokine levels in the lungs. In contrast, almost no differences were observed between the TAL treatment and sham groups. In the second experiment with a lethal lung injury model, the TAL treatment dramatically improved the survival rate of the rats compared to the MGV treatment groups (<italic>p</italic> = 0.0079). Histopathological analysis confirmed pronounced differences in neutrophil accumulation and thickening of the interstitial membrane between the TAL and MGV treatment groups in both experiments. These results indicate that as little as 5 min of TAL treatment can protect rats from acute lung injury by removing causative substances from the lungs.

    DOI

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    2
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  • Synthesis of Biogenic Silver Nanoparticles Using Caesalpinia digyna and Investigation of Their Antimicrobial Activity and In Vivo Biocompatibility

    Mahruba Sultana Niloy, Md. Monir Hossain, Masato Takikawa, Md. Salman Shakil, Shakil Ahmed Polash, Kazi Mustafa Mahmud, Md. Forhad Uddin, Morshed Alam, Razib Datta Shubhra, Mohammad Mahfuz Ali Khan Shawan, Tanushree Saha, Shinji Takeoka, Md. Ashraful Hasan, Satya Ranjan Sarker

    ACS Applied Bio Materials   3 ( 11 ) 7722 - 7733  2020年11月

    DOI

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    17
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  • 人工血小板製剤の臨床応用に向けて 腸間膜動脈出血に対するH12-(ADP)-リポソームを用いたDamage control surgery

    萩沢 康介, 石田 治, 木下 学, 武岡 真司

    人工血液   28 ( 1 ) 20 - 20  2020年11月

  • 人工血小板製剤の臨床応用に向けて 人工血小板H12-(ADP)-リポソーム臨床試験の実現にむけて

    石田 治, 萩沢 康介, 木下 学, 武岡 真司

    人工血液   28 ( 1 ) 21 - 21  2020年11月

  • A rapid and highly sensitive biomarker detection platform based on a temperature-responsive liposome-linked immunosorbent assay.

    Runkai Hu, Keitaro Sou, Shinji Takeoka

    Scientific reports   10 ( 1 ) 18086 - 18086  2020年10月  [国際誌]

     概要を見る

    The enzyme-linked immunosorbent assay (ELISA) is widely used in various fields to detect specific biomarkers. However, ELISA tests have limited detection sensitivity (≥ 1 pM), which is insufficiently sensitive for the detection of small amounts of biomarkers in the early stages of disease or infection. Herein, a method for the rapid and highly sensitive detection of specific antigens, using temperature-responsive liposomes (TLip) containing a squaraine dye that exhibits fluorescence at the phase transition temperature of the liposomes, was developed. A proof-of-concept study using biotinylated TLip and a streptavidin-immobilized microwell plate showed that the TLip bound to the plate via specific molecular recognition could be distinguished from unbound TLip within 1 min because of the difference in the heating time required for the fluorescence emission of TLip. This system could be used to detect prostate specific antigen (PSA) based on a sandwich immunosorbent assay using detection and capture antibodies, in which the limit of detection was as low as 27.6 ag/mL in a 100-μL PSA solution, 0.97 aM in terms of molar concentration. The present temperature-responsive liposome-linked immunosorbent assay provides an advanced platform for the rapid and highly sensitive detection of biomarkers for use in diagnosis and biological inspections.

    DOI PubMed

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    17
    被引用数
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  • Enhanced In Vitro Magnetic Cell Targeting of Doxorubicin-Loaded Magnetic Liposomes for Localized Cancer Therapy

    Eugenio Redolfi Riva, Edoardo Sinibaldi, Agostina Francesca Grillone, Serena Del Turco, Alessio Mondini, Tianshu Li, Shinji Takeoka, Virgilio Mattoli

    Nanomaterials   10 ( 11 ) 2104  2020年10月  [査読有り]

    DOI

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    11
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  • Therapeutic potential of fibrinogen γ-chain peptide-coated, ADP-encapsulated liposomes as a haemostatic adjuvant for post-cardiopulmonary bypass coagulopathy.

    Osamu Ishida, Kohsuke Hagisawa, Nozomu Yamanaka, Koji Tsutsumi, Hidenori Suzuki, Masato Takikawa, Shinji Takeoka, Manabu Kinoshita

    Scientific reports   10 ( 1 ) 11308 - 11308  2020年07月  [査読有り]  [国際誌]

     概要を見る

    Fibrinogen γ-chain peptide-coated, adenosine 5'-diphosphate (ADP)-encapsulated liposomes (H12-ADP-liposomes) are a potent haemostatic adjuvant to promote platelet thrombi. These liposomes are lipid particles coated with specific binding sites for platelet GPIIb/IIIa and encapsulating ADP. They work at bleeding sites, facilitating haemostasis by promoting aggregation of activated platelets and releasing ADP to strongly activate platelets. In this study, we investigated the therapeutic potential of H12-ADP-liposomes on post-cardiopulmonary bypass (CPB) coagulopathy in a preclinical setting. We created a post-CPB coagulopathy model using male New Zealand White rabbits (body weight, 3 kg). One hour after CPB, subject rabbits were intravenously administered H12-ADP-liposomes with platelet-rich plasma (PRP) collected from donor rabbits (H12-ADP-liposome/PRP group, n = 8) or PRP alone (PRP group, n = 8). Ear bleeding time was greatly reduced for the H12-ADP-liposome/PRP group (263 ± 111 s) compared with the PRP group (441 ± 108 s, p < 0.001). Electron microscopy showed platelet thrombus containing liposomes at the bleeding site in the H12-ADP-liposome/PRP group. However, such liposome-involved platelet thrombi were not observed in the end organs after H12-ADP-liposome administration. These findings suggest that H12-ADP-liposomes could help effectively and safely consolidate platelet haemostasis in post-CPB coagulopathy and may have potential for reducing bleeding complications after cardiovascular surgery with CPB.

    DOI PubMed

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    6
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  • Graphene/Au Hybrid Antenna Coil Exfoliated with Multi-Stacked Graphene Flakes for Ultra-Thin Biomedical Devices

    Yuma Tetsu, Yusuke Kido, Meiting Hao, Shinji Takeoka, Takeshi Maruyama, Toshinori Fujie

    ADVANCED ELECTRONIC MATERIALS   6 ( 2 )  2020年02月  [査読有り]

     概要を見る

    Flexible electronics with organic substrates have been developed for bio-conformable devices and soft robotics. Although biodegradable polymers are preferred substrates for biomedical applications, they have poor heat durability, which precludes printing of conductive lines that require annealing at high temperatures (>250 degrees C). The fabrication of an ultra-flexible, inkjet-printed antenna coil with a resistivity of 4.30 x 10(-5) omega-cm is reported. It involves annealing of a graphene/Au antenna coil printed on a glass substrate and transferring onto a 182-nm-thick poly(D, L-lactic acid) nanosheet by exfoliation of multi-stacked graphene flakes. Then, a light-emitting device, powered wirelessly, even in the rounded, twisted, or attached states, is fabricated by mounting a blue LED chip on the nanosheet antenna coil. The self-deploying device is also stored in a water-soluble capsule, injected into a silicone bag, released from the dissolved capsule, and operated wirelessly. This work facilitates the hybridization of conductive lines and biodegradable polymers on ultra-flexible biomaterials for the biomedical application of flexible electronics.

    DOI

    Scopus

    10
    被引用数
    (Scopus)
  • A novel strategy for hemostatic resuscitation using platelet substitute: H12-(ADP)-liposome

    Kohsuke HAGISAWA, Manabu KINOSHITA, Shinji TAKEOKA

    Japanese Journal of Thrombosis and Hemostasis   31 ( 5 ) 505 - 514  2020年

    DOI

  • Ultra-thin, transparent, porous substrates as 3D culture scaffolds for engineering ASC spheroids for high-magnification imaging

    Yoshitaka Suematsu, Ya An Tsai, Shinji Takeoka, Clemens M. Franz, Satoshi Arai, Toshinori Fujie

    Journal of Materials Chemistry B    2020年  [査読有り]

     概要を見る

    <p>We investigated a porous nanosheet to induce the formation of spheroids consisting of adipose-tissue derived stem cells, which is useful not only for engineering 3D cellular organization, but also for imaging the detailed structure of the spheroid.</p>

    DOI

    Scopus

    3
    被引用数
    (Scopus)
  • Combination therapy using fibrinogen γ-chain peptide-coated, ADP-encapsulated liposomes and hemoglobin vesicles for trauma-induced massive hemorrhage in thrombocytopenic rabbits.

    Hagisawa K, Kinoshita M, Takikawa M, Takeoka S, Saitoh D, Seki S, Sakai H

    Transfusion   59 ( 10 ) 3186 - 3196  2019年07月  [査読有り]

    DOI PubMed

    Scopus

    24
    被引用数
    (Scopus)
  • Sinter-free stretchable conductive inks composed of polystyrene-block-polybutadiene-block-polystyrene and silver flakes in tetrahydrofuran.

    Nakanishi, T, Yamagishi, K, Iwase, E, Hiroyasu, I, Takeoka, S, Fujie, T

    Appl. Phys. Express.   12   075001 - 075001  2019年06月  [査読有り]

  • NLRP3 inflammasome-activating arginine-based liposomes promote antigen presentations in dendritic cells

    Tianshu Li, Matthias Zehner, Jieyan He, Tomasz Próchnicki, Gabor Horvath, Eicke Latz, Sven Burgdorf, Shinji Takeoka

    International Journal of Nanomedicine   14   3503 - 3516  2019年05月  [査読有り]

    DOI

    Scopus

    16
    被引用数
    (Scopus)
  • Efficient differentiation and polarization of primary cultured neurons on poly(lactic acid) scaffolds with microgrooved structures

    Asako Otomo, Mahoko Takahashi Ueda, Toshinori Fujie, Arihiro Hasebe, Yosuke Okamura, Shinji Takeoka, Shinji Hadano, So Nakagawa

    bioRxiv   644781  2019年05月

  • Membrane fusogenic lysine type lipid assemblies possess enhanced NLRP3 inflammasome activation potency

    Jieyan He, Tianshu Li, Tomasz Próchnicki, Gabor Horvath, Eicke Latz, Shinji Takeoka

    Biochemistry and Biophysics Reports   18   100623 - 100623.  2019年04月  [査読有り]

    DOI

    Scopus

    11
    被引用数
    (Scopus)
  • An Assay to Evaluate the Function of Liposomal Platelet Substitutes Delivered to Platelet Aggregates

    Suyun Janet Tan, Keiko Nakahara, Keitaro Sou, Shinji Takeoka

    FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY   7  2019年04月

     概要を見る

    Aggregation of liposomal platelet substitutes with activated platelets is the primary endpoint to estimate hemostatic potential. Although light transmission aggregometry is a "gold standard" in assessing platelet aggregation in vitro, this method is less specific and sensitive when tested using liposomal platelet substitutes. In the current study, a new method is developed to evaluate the function of platelet substitutes. By labeling liposomes with a fluorescent dye, DiD, we evaluated their ability to target platelet aggregates using a fluorescence microscope. By incorporating an image-based 96 microtiter microplate, this method was optimized by varying the final lipid concentrations and washing times and validated using unmodified liposomes (e.g., L550 with 0 mol% of carboxylic headgroup lipid; L551 with 9 mol% of carboxylic headgroup lipid) and modified liposomes (e.g., H12-L551 with 9 mol% of carboxylic headgroup lipid and 0.3 mol% of dodecapeptide). Our results showed that 2001 mu M of H12-L551 liposomes and four washes represent optimal conditions for quantitative fluorescence imaging. This method allowed users to qualitatively observe the fluorescently labeled liposomes involved in platelet aggregates. The imaging analysis tool was sufficiently sensitive to quantitatively determine the significantly enhanced delivery of the modified liposomes to platelet aggregates. This enhancement was achieved using dodecapeptide, which specifically binds to activated platelets. This robust and high-throughput method enables the evaluation of liposome function and should facilitate the development of platelet substitutes with a greater ability to target platelet aggregates.

    DOI

    Scopus

    2
    被引用数
    (Scopus)
  • Biohybrid Actuators Based on Skeletal Muscle-Powered Microgrooved Ultra-Thin Films Consisting of Poly(styreneblock-butadiene-block-styrene)

    Hasebe, A, Suematsu, Y, Takeoka, S, Mazzocchi, T, Vannozzi, L, Ricotti, L, Fujie, T

    ACS Biomater. Sci. Eng.   in press  2019年03月  [査読有り]  [招待有り]

  • Ultra-thin and Stretchable Rechargeable Devices with Organic Polymer Nanosheets Conformable to Skin Surface

    Hatakeyama-Sato, K, Wakamatsu, H, Yamagishi, K, Fujie, T, Takeoka, S, Oyaizu, K, Hiroyuki, N

    Small   15   1805296 - 1805296  2019年02月  [査読有り]

  • An Assay to Evaluate the Function of Liposomal Platelet Substitutes Delivered to Platelet Aggregates.

    Suyun Janet Tan, Keiko Nakahara, Keitaro Sou, Shinji Takeoka

    Frontiers in bioengineering and biotechnology   7   77 - 77  2019年  [国際誌]

     概要を見る

    Aggregation of liposomal platelet substitutes with activated platelets is the primary endpoint to estimate hemostatic potential. Although light transmission aggregometry is a "gold standard" in assessing platelet aggregation in vitro, this method is less specific and sensitive when tested using liposomal platelet substitutes. In the current study, a new method is developed to evaluate the function of platelet substitutes. By labeling liposomes with a fluorescent dye, DiD, we evaluated their ability to target platelet aggregates using a fluorescence microscope. By incorporating an image-based 96 microtiter microplate, this method was optimized by varying the final lipid concentrations and washing times and validated using unmodified liposomes (e.g., L550 with 0 mol% of carboxylic headgroup lipid; L551 with 9 mol% of carboxylic headgroup lipid) and modified liposomes (e.g., H12-L551 with 9 mol% of carboxylic headgroup lipid and 0.3 mol% of dodecapeptide). Our results showed that 200 μM of H12-L551 liposomes and four washes represent optimal conditions for quantitative fluorescence imaging. This method allowed users to qualitatively observe the fluorescently labeled liposomes involved in platelet aggregates. The imaging analysis tool was sufficiently sensitive to quantitatively determine the significantly enhanced delivery of the modified liposomes to platelet aggregates. This enhancement was achieved using dodecapeptide, which specifically binds to activated platelets. This robust and high-throughput method enables the evaluation of liposome function and should facilitate the development of platelet substitutes with a greater ability to target platelet aggregates.

    DOI PubMed

    Scopus

    2
    被引用数
    (Scopus)
  • Investigation of the Antibacterial Activity and in vivo Cytotoxicity of Biogenic Silver Nanoparticles as Potent Therapeutics.

    Md Monir Hossain, Shakil Ahmed Polash, Masato Takikawa, Razib Datta Shubhra, Tanushree Saha, Zinia Islam, Sharif Hossain, Md Ashraful Hasan, Shinji Takeoka, Satya Ranjan Sarker

    Frontiers in bioengineering and biotechnology   7   239 - 239  2019年  [査読有り]  [国際誌]

     概要を見る

    Biogenic nanoparticles are the smartest weapons to deal with the multidrug-resistant "superbugs" because of their broad-spectrum antibacterial propensity as well as excellent biocompatibility. The aqueous biogenic silver nanoparticles (Aq-bAgNPs) and ethanolic biogenic silver nanoparticles (Et-bAgNPs) were synthesized using aqueous and ethanolic extracts of Andrographis paniculata stem, respectively, as reducing agents. Electron microscopic images confirmed the synthesis of almost spherical shaped biogenic silver nanoparticles (bAgNPs). The zeta potentials of the nanoparticles were negative and were -22 and -26 mV for Aq-bAgNPs and Et-bAgNPs, respectively. The antibacterial activity of bAgNPs was investigated against seven pathogenic (i.e., enteropathogenic Escherichia coli, Salmonella typhi, Staphylococcus aureus, Vibrio cholerae, Enterococcus faecalis, Hafnia alvei, Acinetobacter baumannii) and three nonpathogenic (i.e., E. coli DH5α, E. coli K12, and Bacillus subtilis) bacteria at different time points (i.e., 12, 16, 20, and 24 h) in a dose-dependent manner (i.e., 20, 40, and 60 μg) through broth dilution assay, disk diffusion assay, CellToxTM Green uptake assay, and trypan blue dye exclusion assay. The lowest minimum inhibitory concentration value for both the bAgNPs was 0.125 μg. Et-bAgNPs showed the highest antibacterial activity against S. aureus at 60 μg after 16 h and the diameter of inhibited zone was 28 mm. Lipid peroxidation assay using all the bacterial strains revealed the formation of malondialdehyde-thiobarbituric acid adduct due to the oxidation of cell membrane fatty acids by bAgNPs. The bAgNPs showed excellent hemocompatibility against human as well as rat red blood cells. Furthermore, there was no significant toxicity observed when the levels of rat serum ALT, AST, γ-GT (i.e., liver function biomarkers), and creatinine (i.e., kidney function biomarker) were determined.

    DOI PubMed

    Scopus

    59
    被引用数
    (Scopus)
  • Printed Nanofilms Mechanically Conforming to Living Bodies

    Yamagishi, K, Takeoka, S, Fujie, T

    Biomater. Sci.   7   520 - 531  2019年01月  [査読有り]  [招待有り]

  • Inkjet-Printed Neural Electrodes with Mechanically Gradient Structure

    Kokubo, N, Arake, M, Yamagishi, K, Morimoto, Y, Takeoka, S, Ohta, H, Fujie, T

    ACS Appl. Bio Mater.   2   20 - 26  2018年12月  [査読有り]

  • Extracellular pH imaging of a plant leaf with a polyelectrolyte multilayered nanosheet

    藤枝 俊宣

    RSC Advances   8   35651 - 35657  2018年10月  [査読有り]

  • In situ transplantation of adipose tissue-derived stem cells organized on porous polymer nanosheets for murine skin defects.

    Nishiwaki K, Aoki S, Kinoshita M, Kiyosawa T, Suematsu Y, Takeoka S, Fujie T

    Journal of biomedical materials research. Part B, Applied biomaterials    2018年09月  [査読有り]

    DOI PubMed

    Scopus

    12
    被引用数
    (Scopus)
  • Tissue-adhesive wirelessly powered optoelectronic device for metronomic photodynamic cancer therapy

    Kento Yamagishi, Izumi Kirino, Isao Takahashi, Hizuru Amano, Shinji Takeoka, Yuji Morimoto, Toshinori Fujie

    Nature Biomedical Engineering    2018年07月  [査読有り]

    DOI

    Scopus

    142
    被引用数
    (Scopus)
  • Lysine-containing cationic liposomes activate the NLRP3 inflammasome: Effect of a spacer between the head group and the hydrophobic moieties of the lipids

    Tianshu Li, Jieyan He, Gabor Horvath, Tomasz Próchnicki, Eicke Latz, Shinji Takeoka

    Nanomedicine: Nanotechnology, Biology, and Medicine   14 ( 2 ) 279 - 288  2018年02月  [査読有り]

     概要を見る

    Cationic lipids containing lysine head groups and ditetradecyl, dihexadecyl or dioctadecyl glutamate hydrophobic moieties with/without propyl, pentyl or heptyl spacers were applied for the preparation of cationic liposomes using a simple bath type-sonicator. The size distribution, zeta potential, cellular internalization, and cytotoxicity of the liposomes were characterized, and the innate immune stimulation, e.g., the NLRP3 inflammasome activation of human macrophages and THP-1 cells, was evaluated by the detection of IL-1β release. Comparatively, L3C14 and L5C14 liposomes, made from the lipids bearing lysine head groups, ditetradecyl hydrophobic chains and propyl or pentyl spacers, respectively, were the most potent to activate the NLRP3 inflammasome. The possible mechanism includes endocytosis of the cationic liposomes and subsequent lysosome rupture without significant inducement of reactive oxygen species production. In summary, we first disclosed the structural effect of cationic liposomes on the NLRP3 inflammasome activation, which gives an insight into the application of nanoparticles for improved immune response.

    DOI PubMed

    Scopus

    24
    被引用数
    (Scopus)
  • MEMS optical interferometry-based pressure sensor using elastomer nanosheet developed by dry transfer technique

    Takahashi, K, Fujie, T, Sato, N, Takeoka, S, Sawada, K

    Jpn. J. Appl. Phys.   57   010302 - 010302  2017年12月  [査読有り]

  • The efficacy of basic fibroblast growth factor-loaded poly(lactic-co-glycolic acid) nanosheet for mouse wound healing

    Shimpo Aoki, Mao Fujii, Toshinori Fujie, Keisuke Nishiwaki, Hiromi Miyazaki, Daizoh Saitoh, Shinji Takeoka, Tomoharu Kiyosawa, Manabu Kinoshita

    Wound Repair and Regeneration   25 ( 6 ) 1008 - 1016  2017年11月  [査読有り]

     概要を見る

    Although human recombinant basic fibroblast growth factor (bFGF) is widely used for wound healing, daily treatment with bFGF is required because of its short half-life. An effective controlled-release system of bFGF is, therefore, desired in clinical settings. To investigate the efficacy of a bFGF-loaded nanosheet for wound healing, focusing on the controlled-release of bFGF, bFGF-loaded poly(lactic-co-glycolic acid) (PGLA) nanosheets were developed, and their in vitro release profile of bFGF and their in vivo efficacy for wound healing were examined. A polyion complex of positively charged human recombinant bFGF and negatively charged alginate was sandwiched between PLGA nanosheets (70 nm thick for each layer). The resulting bFGF-loaded nanosheet robustly adhered to silicon skin by observation using a microscratch test. bFGF was gradually and continuously released over three days in an in vitro incubation study. Treatment with the bFGF-loaded nanosheets (every 3 day for 15 days) as well as with a conventional bFGF spray effectively promoted wound healing of mouse dorsal skin defects with accelerated tissue granulation and angiogenesis, although the dose of bFGF used in the treatment with the bFGF nanosheets was approximately 1/20 of the sprayed bFGF. In conclusion, we developed a bFGF-loaded nanosheet that sustained a continuous release of bFGF over three days and effectively promoted wound healing in mice.

    DOI PubMed

    Scopus

    16
    被引用数
    (Scopus)
  • 衝撃波による致死的肺出血マウスに対する新規リポゾーム製剤H12-ADP-liposomeの肺保護効果

    萩沢 康介, 木下 学, 宮脇 博基, 佐藤 俊一, 鈴木 英紀, 武岡 真司, 斎藤 大蔵

    エンドトキシン・自然免疫研究   20   28 - 30  2017年10月

  • Adhesive and robust multilayered poly(lactic acid) nanosheets for hemostatic dressing in liver injury model

    Takuya Komachi, Hideaki Sumiyoshi, Yutaka Inagaki, Shinji Takeoka, Yu Nagase, Yosuke Okamura

    JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B-APPLIED BIOMATERIALS   105 ( 7 ) 1747 - 1757  2017年10月  [査読有り]

     概要を見る

    Freestanding biodegradable nanosheets composed of poly(l-lactic acid) (PLLA) have been developed for various biomedical applications. These nanosheets exhibit unique properties such as high adhesiveness and exquisite flexibility; however, they burst easily due to their nanometer thickness. We herein describe a freestanding, multilayered nanosheet composed of PLLA fabricated using a simple combination procedure: (i) multilayering of PLLA and alginate, (ii) gelation of the alginate layers, (iii) fusion-cut sealing, and (iv) elution of the alginate layers. The multilayered nanosheets not only reinforced the bursting strength but also provided a high level of adhesive strength. In fact, they were found to show potential as a hemostatic dressing, and they tended to show reduced tissue adhesion that accompanies liver injury. Therefore, we propose this biomaterial as a candidate for an alternative to conventional therapy in hemorrhage. (c) 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1747-1757, 2017.

    DOI PubMed

    Scopus

    22
    被引用数
    (Scopus)
  • Effect of Living Body on Performance of RF Identifier Antenna Printed on Ultrathin Polymer Film

    H.HAYATA, M.OKAMOTO, S.TAKEOKA, E.IWASE, T.FUJIE, H.IWATA

    International Conference on Flexible and Printed Electronics (ICFPE 2017)   paper no. P083  2017年09月  [査読有り]

  • On the injectability of free-standing magnetic nanofilms

    Silvia Taccola, Virginia Pensabene, Toshinori Fujie, Shinji Takeoka, Nicola M. Pugno, Virgilio Mattoli

    BIOMEDICAL MICRODEVICES   19 ( 3 ) 51  2017年09月  [査読有り]

     概要を見る

    Free-standing films with sub-micrometric thickness, composed of soft polymers and functional nanostructures are promising candidates for many potential applications in the biomedical field, such as reduced port abdominal surgery. In this work, freely suspended poly(L-lactic acid) nanofilms with controlled morphology embedding superparamagnetic iron oxide nanoparticles were fabricated by spin-coating deposition. The mechanical properties of magnetic nanofilms were investigated by Strain-Induced Elastic Buckling Instability for Mechanical Measurements (SIEBIMM) test. Our results show that these freely suspended nanocomposite nanofilms are highly flexible and deformable, withYoung's moduli of few GPa. Since they can be handled in liquid with syringes, a quantitative description of the nanofilms behavior during the manipulation with clinically applicable needles has been also provided. These magnetic nanofilms, remotely controllable by external electromagnetic fields, have potential applications in minimally invasive surgery as injectable nanopatches on inner organs wall.

    DOI PubMed

    Scopus

    8
    被引用数
    (Scopus)
  • Preparation, Characterization, and Preliminary In Vitro Testing of Nanoceria-Loaded Liposomes

    Agostina Grillone, Tianshu Li, Matteo Battaglini, Alice Scarpellini, Mirko Prato, Shinji Takeoka, Gianni Ciofani

    NANOMATERIALS   7 ( 9 )  2017年09月  [査読有り]

     概要を見る

    Cerium oxide nanoparticles (nanoceria), well known for their pro-and antioxidant features, have been recently proposed for the treatment of several pathologies, including cancer and neurodegenerative diseases. However, interaction between nanoceria and biological molecules such as proteins and lipids, short blood circulation time, and the need of a targeted delivery to desired sites are some aspects that require strong attention for further progresses in the clinical application of these nanoparticles. The aim of this work is the encapsulation of nanoceria into a liposomal formulation in order to improve their therapeutic potentialities. After the preparation through a reverse- phase evaporation method, size, Z-potential, morphology, and loading efficiency of nanoceria-loaded liposomes were investigated. Finally, preliminary in vitro studies were performed to test cell uptake efficiency and preserved antioxidant activity. Nanoceria-loaded liposomes showed a good colloidal stability, an excellent biocompatibility, and strong antioxidant properties due to the unaltered activity of the entrapped nanoceria. With these results, the possibility of exploiting liposomes as carriers for cerium oxide nanoparticles is demonstrated here for the first time, thus opening exciting new opportunities for in vivo applications.

    DOI PubMed

    Scopus

    18
    被引用数
    (Scopus)
  • Effect of the nanoformulation of siRrNAa-lipid assemblies on their cellular uptake and immune stimulation

    Kohei Kubota, Kohei Onishi, Kazuaki Sawaki, Tianshu Li, Kaoru Mitsuoka, Takaaki Sato, Shinji Takeoka

    International Journal of Nanomedicine   12   5121 - 5133  2017年07月  [査読有り]

     概要を見る

    Two lipid-based nanoformulations have been used to date in clinical studies: lipoplexes and lipid nanoparticles (LNPs). In this study, we prepared small interfering RNA (siRNA)-loaded carriers using lipid components of the same composition to form molecular assemblies of differing structures, and evaluated the impact of structure on cellular uptake and immune stimulation. Lipoplexes are electrostatic complexes formed by mixing preformed cationic lipid liposomes with anionic siRNA in an aqueous environment, whereas LNPs are nanoparticles embedding siRNA prepared by mixing an alcoholic lipid solution with an aqueous siRNA solution in one step. Although the physicochemical properties of lipoplexes and LNPs were similar except for small increases in apparent size of lipoplexes and zeta potential of LNPs, siRNA uptake efficiency of LNPs was significantly higher than that of lipoplexes. Furthermore, in the case of LNPs, both siRNA and lipid were effectively incorporated into cells in a co-assembled state
    however, in the case of lipoplexes, the amount of siRNA internalized into cells was small in comparison with lipid. siRNAs in lipoplexes were thought to be more likely to localize on the particle surface and thereby undergo dissociation into the medium. Inflammatory cytokine responses also appeared to differ between lipoplexes and LNPs. For tumor necrosis factor-a, release was mainly caused by siRNA. On the other hand, the release of interleukin-1β was mainly due to the cationic nature of particles. LNPs released lower amounts of tumor necrosis factor-a and interleukin-1β than lipoplexes and were thus considered to be better tolerated with respect to cytokine release. In conclusion, siRNA-loaded nanoformulations effect their cellular uptake and immune stimulation in a manner that depends on the structure of the molecular assembly
    therefore, nanoformulations should be optimized before extending studies into the in vivo environment.

    DOI PubMed

    Scopus

    20
    被引用数
    (Scopus)
  • Ultrathin epidermal strain sensor based on an elastomer nanosheet with an inkjet-printed conductive polymer

    Tetsu Yuma, Yamagishi Kento, Kato Akira, Matsumoto Yuya, Tsukune Mariko, Kobayashi Yo, Fujie Masakatsu, Takeoka Shinji, Fujie Toshinori

    Appl. Phys. Express   10 ( 8 )  2017年07月

     概要を見る

    To minimize the interference that skin-contact strain sensors cause natural skin deformation, physical conformability to the epidermal structure is critical. Here, we developed an ultrathin strain sensor made from poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) inkjet-printed on a polystyrene–polybutadiene–polystyrene (SBS) nanosheet. The sensor, whose total thickness and gauge factor were ∼1 µm and 0.73 ± 0.10, respectively, deeply conformed to the epidermal structure and successfully detected the small skin strain (∼2%) while interfering minimally with the natural deformation of the skin. Such an epidermal strain sensor will open a new avenue for precisely detecting the motion of human skin and artificial soft-robotic skin.

    CiNii

  • Pore Clogging of Colloidal Mesoporous Silica Nanoparticles for Encapsulating Guest Species

    Eisuke Yamamoto, Kouya Nagata, Kenta Onishi, Chihiro Urata, Atsushi Shimojima, Hiroaki Wada, Shinji Takeoka, Kazuyuki Kuroda

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   90 ( 6 ) 706 - 708  2017年06月  [査読有り]

     概要を見る

    Colloidal mesoporous silica nanoparticles (CMS) are useful as carriers for imaging probes because of their unique features. A simple method for the pore clogging of CMS has been proved by the addition of tetraethoxysilane under weakly basic conditions. The pore clogging of CMS is useful for encapsulation of thermoresponsive dyes.

    DOI

    Scopus

    5
    被引用数
    (Scopus)
  • Printed high-frequency RF identification antenna on ultrathin polymer film by simple production process for soft-surface adhesive device

    Hiroki Hayata, Marin Okamoto, Shinji Takeoka, Eiji Iwase, Toshinori Fujie, Hiroyasu Iwata

    JAPANESE JOURNAL OF APPLIED PHYSICS   56 ( 5 ) 05EC01  2017年05月  [査読有り]

     概要を見る

    In this paper, we present a simple method for manufacturing electronic devices using ultrathin polymer films, and develop a high-frequency RF identification. To expand the market for flexible devices, it is important to enhance their adhesiveness and conformability to surfaces, to simplify their fabrication, and to reduce their cost. We developed a method to design an antenna for use on an operable RF identification whose wiring was subjected to commercially available inkjet or simple screen printing, and successfully fabricated the RF identification. By using ultrathin films made of polystyrene-block-polybutadiene-block-polystyrene (SBS) as substrates-less than 750nm-the films could be attached to various surfaces, including soft surfaces, by van der Waals force and without using glue. We succeeded in the simple fabrication of an ultrathin RF identification including a commercial or simple printing process. (C) 2017 The Japan Society of Applied Physics

    DOI

    Scopus

    7
    被引用数
    (Scopus)
  • Construction and evaluation of pH-sensitive immunoliposomes for enhanced delivery of anticancer drug to ErbB2 over-expressing breast cancer cells

    Tianshu Li, Takuya Amari, Kentaro Semba, Tadashi Yamamoto, Shinji Takeoka

    NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE   13 ( 3 ) 1219 - 1227  2017年04月  [査読有り]

     概要を見る

    1,5-Dihexadecyl N, N-diglutamyl-lysyl-L-glutamate (GGLG) liposomes were previously developed to enhance drug delivery efficiency in tumor cells owing to its pH-responsive properties. Herein, we report the modification of GGLG liposomes by conjugating a Fab' fragment of an ErbB2 antibody to the terminus of PEG (polyethylene glycol)-lipid (Fab'-GGLGliposomes). The conjugation of Fab' fragments did not affect the antibody activity, drug (doxorubicin, DOX) encapsulation efficiency, stability during storage or pH-sensitivity. However, the binding affinity of Fab'-GGLG liposomes was enhanced to ErbB2-overexpressing HCC1954 cells specifically, and the cell association increased 10-fold in comparison to GGLG liposomes. Consequently, intracellular DOX delivery was enhanced, with an increased cytotoxicity in HCC1954 cells (i.e., IC50 of 1.17 and 3.08 mu g/mL for Fab'-GGLG-DOX and GGLG-DOX liposomes, respectively). Further, a significantly enhanced tumor growth inhibition was obtained in an ErbB2-overexpressing breast cancer-bearing mouse model. Therefore, a potent anticancer drug delivery system was constructed by the immunological modification of pH-sensitive liposomes. (C) 2016 Elsevier Inc. All rights reserved.

    DOI PubMed

    Scopus

    33
    被引用数
    (Scopus)
  • Sandwich fixation of electronic elements using free-standing elastomeric nanosheets for low-temperature device processes

    Marin Okamoto, Mizuho Kurotobi, Shinji Takeoka, Junki Sugano, Eiji Iwase, Hiroyasu Iwata, Toshinori Fujie

    JOURNAL OF MATERIALS CHEMISTRY C   5 ( 6 ) 1321 - 1327  2017年02月  [査読有り]

     概要を見る

    We fabricated free-standing, flexible and physically adhesive ultrathin elastomeric films (nanosheets) for application as electronic substrates and packaging films. In this work, electronic elements such as a chip resistor and a chip LED were sandwiched between elastomeric nanosheets of less than 1 mu m thickness to obtain electrical conduction in silver lines that were inkjet-printed on the nanosheet. This sandwich-fixation process contributed to the development of an electronic device showing conformable adhesion and operation on the skin surface.

    DOI

    Scopus

    13
    被引用数
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  • Glue-Free Stacked Luminescent Nanosheets Enable High-Resolution Ratiometric Temperature Mapping in Living Small Animals (vol 8, pg 33377, 2016)

    Takuya Miyagawa, Toshinori Fujie, Ferdinandus, Tat Thang Vo Doan, Hirotaka Sato, Shinji Takeoka

    ACS APPLIED MATERIALS & INTERFACES   9 ( 7 ) 6652 - 6652  2017年02月  [査読有り]

    DOI PubMed

  • Construction of A New Cs+ Extraction Process by Using Calix Crown-Containing Magnetic Nanoparticle-Loaded Fragmented Nanosheets

    Katsunori Sato, Gen Noguchi, Kohei Asao, Atsushi Murata, Toshinori Fujie, Yu Nagase, Shinji Takeoka

    KOBUNSHI RONBUNSHU   74 ( 2 ) 99 - 108  2017年  [査読有り]

     概要を見る

    The treatment of radioactive Cs+-polluted waste is now a serious issue in Fukushima. In this study, construction of a new Cs+ absorbent: calix crown-containing magnetic nanoparticle-loaded fragmented nanosheets (SFNs) was carried out by addressing the following points: calix crown as a Cs+-capturing mechanism, aromatic polyamide/polyimide as an ingredient of absorbent for better chemical and physical resistance, polymer nanosheet as the immobilization platform to enhance the contact area of the absorbent toward the polluted solution, magnetic nanoparticles, loaded onto nanosheet, and the fragmentation of nanosheet for simple use in a polluted solution. As a result, SFNs were successfully prepared and revealed to have Cs+ selectivity and reusability. Also, SFNs in solution caught Cs+ and were manipulated by magnetic force. The Cs extraction process is an effective method by circulating absorbents between polluted solution and the cleaning solution by electromagnetic operation.

    DOI

    Scopus

  • Effect of the nanoformulation of siRNA-lipid assemblies on their cellular uptake and immune stimulation

    Kohei Kubota, Kohei Onishi, Kazuaki Sawaki, Tianshu Li, Kaoru Mitsuoka, Takaaki Sato, Shinji Takeoka

    INTERNATIONAL JOURNAL OF NANOMEDICINE   12   5121 - 5133  2017年  [査読有り]

     概要を見る

    Two lipid-based nanoformulations have been used to date in clinical studies: lipoplexes and lipid nanoparticles (LNPs). In this study, we prepared small interfering RNA (siRNA)-loaded carriers using lipid components of the same composition to form molecular assemblies of differing structures, and evaluated the impact of structure on cellular uptake and immune stimulation. Lipoplexes are electrostatic complexes formed by mixing preformed cationic lipid liposomes with anionic siRNA in an aqueous environment, whereas LNPs are nanoparticles embedding siRNA prepared by mixing an alcoholic lipid solution with an aqueous siRNA solution in one step. Although the physicochemical properties of lipoplexes and LNPs were similar except for small increases in apparent size of lipoplexes and zeta potential of LNPs, siRNA uptake efficiency of LNPs was significantly higher than that of lipoplexes. Furthermore, in the case of LNPs, both siRNA and lipid were effectively incorporated into cells in a co-assembled state; however, in the case of lipoplexes, the amount of siRNA internalized into cells was small in comparison with lipid. siRNAs in lipoplexes were thought to be more likely to localize on the particle surface and thereby undergo dissociation into the medium. Inflammatory cytokine responses also appeared to differ between lipoplexes and LNPs. For tumor necrosis factor-alpha, release was mainly caused by siRNA. On the other hand, the release of interleukin-1 beta was mainly due to the cationic nature of particles. LNPs released lower amounts of tumor necrosis factor-alpha and interleukin-1 beta than lipoplexes and were thus considered to be better tolerated with respect to cytokine release. In conclusion, siRNA-loaded nanoformulations effect their cellular uptake and immune stimulation in a manner that depends on the structure of the molecular assembly; therefore, nanoformulations should be optimized before extending studies into the in vivo environment.

    DOI

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    20
    被引用数
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  • Optomechanical characterization of freestanding stretchable nanosheet based on polystyrene-polybutadiene-polystyrene copolymer

    Hayato Kumagai, Nobutaka Sato, Shinji Takeoka, Kazuaki Sawada, Toshinori Fujie, Kazuhiro Takahashi

    APPLIED PHYSICS EXPRESS   10 ( 1 )  2017年01月  [査読有り]

     概要を見る

    In this study, we fabricated a stretchable freestanding ultrathin sheet based on a polystyrene-polybutadiene-polystyrene (SBS) copolymer with entropy-driven elasticity and evaluated its optomechanical properties. The freestanding SBS sheet had a thickness of 675 nm and a size of 10.4 X 10.4 mm(2) on a through hole of a poly(dimethylsiloxane) (PDMS) sheet. The measurement of the reflection spectra of the optical interference peaks of the stretched sheets revealed that the SBS nanosheet had a Poisson's ratio of 0.5-0.68 for a 38% elastic strain, which is one order of magnitude greater than that of parylene. (C) 2017 The Japan Society of Applied Physics

    DOI

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    6
    被引用数
    (Scopus)
  • 肌に貼り付けるだけで生体情報をモニタリングする電子ナノ絆創膏

    山岸 健人, 武岡 真司, 藤枝 俊宣

    Biophilia   5 ( 4 ) 23 - 29  2017年  [招待有り]

  • Glue-Free Stacked Luminescent Nanosheets Enable High-Resolution Ratiometric Temperature Mapping in Living Small Animals

    Takuya Miyagawa, Toshinori Fujie, Ferdinandus, Tat Thang Vo Doan, Hirotaka Sato, Shinji Takeoka

    ACS APPLIED MATERIALS & INTERFACES   8 ( 49 ) 33377 - 33385  2016年12月  [査読有り]

     概要を見る

    In this paper, a microthermograph, temperature mapping with high spatial resolution, was established using luminescent molecules embedded ultrathin polymeric films (nanosheets), and demonstrated in a living small animal to map out and visualize temperature shift due to animal's muscular activity. Herein, we report super flexible and self-adhesive (no need of glue) nanothermosensor consisting of stacked two different polymeric nanosheets with thermosensitive (Eu-tris (dinaphthoylmethane)-bis-trioctylphosphine oxide: EuDT) and insensitive (Rhodamine 800) dyes being embedded. Such stacked nanosheets allow for the ratiometric thermometry, with which the undesired luminescence intensity shift due to focal drift or animal's z-axis displacement is eliminated and the desired intensity shift solely due to the temperature shift of the sample (living muscle) can be acquired. With the stacked luminescent nanosheets, we achieved the first-ever demonstration of video filming of chronologically changing temperature-shift distribution from the rest state to the active state of the muscles in the living animal. The polymer nanosheet engineering and in vivo microthermography presented in the paper are promising technologies to microscopically explore the heat production and heat transfer in living cells, tissues, and organisms with high spatial resolution beyond what existing thermometric technologies such as infrared thermography have ever achieved.

    DOI PubMed

    Scopus

    27
    被引用数
    (Scopus)
  • Fibrinogen γ-Chain Peptide-Coated Adenosine 5' Diphosphate-Encapsulated Liposomes Rescue Mice From Lethal Blast Lung Injury via Adenosine Signaling.

    Hagisawa K, Kinoshita M, Miyawaki H, Sato S, Miyazaki H, Takeoka S, Suzuki H, Iwaya K, Seki S, Shono S, Saitoh D, Nishida Y, Handa M

    Critical care medicine   44 ( 9 ) E827 - E837  2016年09月  [査読有り]

    DOI PubMed

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    11
    被引用数
    (Scopus)
  • Phospholipase Cβ1 induces membrane tubulation and is involved in caveolae formation.

    Inaba T, Kishimoto T, Murate M, Tajima T, Sakai S, Abe M, Makino A, Tomishige N, Ishitsuka R, Ikeda Y, Takeoka S, Kobayashi T

    Proceedings of the National Academy of Sciences of the United States of America   113 ( 28 ) 7834 - 7839  2016年07月  [査読有り]

    DOI PubMed

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    25
    被引用数
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  • Massive Fabrication of Polymer Microdiscs by Phase Separation and Freestanding Process

    Hong Zhang, Mao Fujii, Yosuke Okamura, Li Zhang, Shinji Takeoka

    ACS APPLIED MATERIALS & INTERFACES   8 ( 25 ) 16296 - 16302  2016年06月  [査読有り]

     概要を見る

    We present a facile method to fabricate polymer thin films with tens of nanometers thickness and several micrometers size (also called "microdiscs" herein) by applying phase separation of polymer blend. A water-soluble supporting layer is employed to obtain a freestanding microdisc suspension. Owing to their miniaturized size, microdiscs can be injected through a syringe needle. Herein, poly(D,L-lactic acid) microdiscs were fabricated with various thicknesses and sizes, in the range from ca. 10 to 60 nm and from ca. 1.0 to 10.0 mu m, respectively. Magnetic nanoparticles were deposited on polymer microdiscs with a surface coating method. The magnetic manipulation of microdiscs in a liquid environment under an external magnetic field was achieved with controllable velocity by adjusting the microdisc dimensions and the loading amount of magnetic components. Such biocompatible polymer microdiscs are expected to serve as injectable vehicles for targeted drug delivery.

    DOI PubMed

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    8
    被引用数
    (Scopus)
  • Polylactic acid nanosheets in prevention of postoperative intestinal adhesion and their effects on bacterial propagation in an experimental model

    A. Hinoki, A. Saito, M. Kinoshita, J. Yamamoto, D. Saitoh, S. Takeoka

    British Journal of Surgery   103 ( 6 ) 692 - 700  2016年05月  [査読有り]

     概要を見る

    Background Ultrathin films (nanosheets) adhere tightly to organ surfaces but prevent adhesion to other organs. The antiadhesive effect of nanosheets and their effect on bacterial propagation were investigated in a murine intestinal adhesion model. Methods Polylactic acid nanosheets (approximately 80 nm thick) were produced. Serosal defects were created by peeling off the intestinal serosa
    these were left open or covered with nanosheets or Seprafilm® and the formation of intestinal adhesions was analysed. To examine bacterial propagation, a nanosheet or Seprafilm® was placed on intact murine jejunum followed by Escherichia coli inoculation at the site. Results Treatment both with nanosheets and with Seprafilm® reduced postoperative intestinal adhesion (mean adhesion score 0·67 for nanosheets, 0·43 for Seprafilm® and 2·87 for no antiadhesive treatment
    P &lt
    0·001 for nanosheets or Seprafilm® versus no adhesive treatment). Nanosheet treatment did not affect bacterial propagation in the peritoneal cavity, whereas Seprafilm®-treated mice showed bacterial propagation, leading to increased mortality. Conclusion Nanosheets may be effective novel antiadhesive agents even in the presence of bacterial contamination. Surgical relevance Intra-abdominal adhesions following surgical contamination can trigger postoperative complications and lead to deterioration in long-term quality of life. However, currently there are no effective antiadhesion materials to prevent the formation of adhesions. Treatment with ultrathin nanosheets effectively reduced postoperative intestinal adhesion in an experimental mouse model, and did not affect bacterial propagation in the peritoneal cavity. These nanosheets are potent novel antiadhesive materials that potentially can be applied even in contaminated conditions.

    DOI PubMed

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    18
    被引用数
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  • Development of a ubiquitously transferrable silver-nanoparticle-loaded polymer nanosheet as an antimicrobial coating

    Keisuke Ito, Akihiro Saito, Toshinori Fujie, Hiromi Miyazaki, Manabu Kinoshita, Daizoh Saitoh, Shinya Ohtsubo, Shinji Takeoka

    JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B-APPLIED BIOMATERIALS   104 ( 3 ) 585 - 593  2016年04月  [査読有り]

     概要を見る

    Ultra-thin polymer films (nanosheets) fabricated by a layer-by-layer (LbL) method possess unique properties such as high flexibility, adhesive strength, and transparency, and can be peeled off from a substrate and attached to various surfaces via a water-soluble supporting film. Therefore, flexible and transferrable LbL nanosheets are convenient tools as coating materials. Here, we fabricated a novel antimicrobial coating material by embedding silver nanoparticles (AgNPs) in an LbL nanosheet composed of layers of chitosan and sodium alginate (Ag-LbL nanosheet) by means of a photo-reduction method. Optimizing the amount of irradiated energy applied led to robust antimicrobial efficacy against methicillin-resistant Staphylococcus aureus (MRSA), sufficient to meet ISO standards (ISO 22196), while maintaining the flexibility and adhesive potency of the LbL nanosheet. Thus, the Ag-LbL nanosheet is a promising coating material that can provide antimicrobial efficacy to various surfaces. (c) 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 585-593, 2016.

    DOI PubMed

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    17
    被引用数
    (Scopus)
  • Interfacial effects on the crystallization and surface properties of poly(l- lactic acid) ultrathin films

    Akihiro Udagawa, Toshinori Fujie, Yuko Kawamoto, Akihiro Saito, Shinji Takeoka, Toru Asahi

    POLYMER JOURNAL   48 ( 2 ) 157 - 161  2016年02月  [査読有り]

     概要を見る

    Polymer crystallization affects structural and mechanical properties of polymer thin films. In this study, we focused on the thermal annealing-induced crystallization in semi-crystalline poly(l-lactic acid) (PLLA) ultrathin films (referred as nanosheets) was investigated in terms of interfacial interaction of PLLA with air and substrate. The surface structure of the PLLA nanosheets observed by atomic force microscopy showed that roughness of the air-side surface increased due to crystallization of PLLA under thermal annealing, whereas that of the substrate-side surface changed little. The elastic moduli and the physical adhesiveness of the nanosheets also changed only on the surface of the air side from crystallization, in contrast to the substrate side. The X-ray diffraction studies of the PLLA nanosheets with different thickness showed that the crystalline contents steeply increased below ca. 200 nm. These results indicated that the crystallization was enhanced near the surface of the air side and restricted near that of the substrate side due to the different interfacial association of the polymer chains in the nanosheet.

    DOI

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    7
    被引用数
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  • Development of Inexpensive Skin Adhesive Electronic Device - RFID Tag Implementation on Ultrathin Polymer Film -

    H.HAYATA, M.OKAMOTO, S.TAKEOKA, E.IWASE, T.FUJIE, H.IWATA

    Int. Conf. on Flexible and Printed Electronics   O5-4  2016年  [査読有り]

  • Facilely Fabricated Luminescent Nanoparticle Thermosensor for Real-Time Microthermography in Living Animals

    Ferdinandus, Arai S, Takeoka S, Ishiwata S, Suzuki M, Sato H

    ACS Sensors   1 ( 10 ) 1222 - 1227  2016年  [査読有り]

    DOI

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    29
    被引用数
    (Scopus)
  • Development of a ubiquitously transferrable silver-nanoparticle-loaded polymer nanosheet as an antimicrobial coating.

    Ito Keisuke, Saito Akihiro, Fujie Toshinori, Miyazaki Hiromi, Kinoshita Manabu, Saitoh Daizoh, Ohtsubo Shinya, Takeoka Shinji

    Journal of biomedical materials research. Part B, Applied biomaterials   104 ( 3 )  2016年  [査読有り]

    DOI PubMed

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    17
    被引用数
    (Scopus)
  • Large-Scale Fabrication of Porous Polymer Nanosheets for Engineering Hierarchical Cellular Organization

    Suzuki, Shoichiro, Nishiwaki, Keisuke, Takeoka, Shinji, Fujie, Toshinori

    ADVANCED MATERIALS TECHNOLOGIES   in press  2016年  [査読有り]

    DOI

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    16
    被引用数
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  • ホスホリルコリン基を有するポリイミドの合成と生体適合性ナノシートの作製

    浅尾 幸平, 荻野 真里, 岩野 篤, 岡村 陽介, 武岡 真司, 長瀬 裕

    高分子論文集   73 ( 1 ) 76 - 86  2016年01月  [査読有り]

    DOI

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    2
    被引用数
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  • Stretchable, adhesive and ultra-conformable elastomer thin films

    Nobutaka Sato, Atsushi Murata, Toshinori Fujie, Shinji Takeoka

    SOFT MATTER   12 ( 45 ) 9202 - 9209  2016年  [査読有り]

     概要を見る

    Thermoplastic elastomers are attractive materials because of the drastic changes in their physical properties above and below the glass transition temperature (T-g). In this paper, we report that free-standing polystyrene (PS, T-g: 100 degrees C) and polystyrene-polybutadiene-polystyrene triblock copolymer (SBS, T-g: -70 degrees C) thin films with a thickness of hundreds of nanometers were prepared by a gravure coating method. Among the mechanical properties of these thin films determined by bulge testing and tensile testing, the SBS thin films exhibited a much lower elastic modulus (ca. 0.045 GPa, 212 nm thickness) in comparison with the PS thin films (ca. 1.19 GPa, 217 nm thickness). The lower elastic modulus and lower thickness of the SBS thin films resulted in higher conformability and thus higher strength of adhesion to an uneven surface such as an artificial skin model with roughness (R-a = 10.6 mu m), even though they both have similar surface energies. By analyzing the mechanical properties of the SBS thin films, the elastic modulus and thickness of the thin films were strongly correlated with their conformability to a rough surface, which thus led to a high adhesive strength. Therefore, the SBS thin films will be useful as coating layers for a variety of materials.

    DOI PubMed

  • Focal calcium monitoring with targeted nanosensors at the cytosolic side of endoplasmic reticulum

    Yanyan Hou, Satoshi Arai, Yoshiaki Takei, Atsushi Murata, Shinji Takeoka, Madoka Suzuki

    SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS   17 ( 1 ) 293 - 299  2016年  [査読有り]

     概要を見る

    Ca2+ distribution is spatially and temporally non-uniform inside cells due to cellular compartmentalization. However, Ca2+ sensing with small organic dyes, such as fura-2 and fluo-4, has been practically applied at a single cell level where the averaged signal from freely diffusing dye molecules is acquired. In this study, we aimed to target azide-functionalized fura-2 (N-3-fura-2) to a specific site of subcellular compartments to realize focal Ca2+ sensing. Using scAVD (single-chain avidin)-biotin interaction and a copper-free click reaction system, we linked N-3-fura-2 to specifically-targeted scAVD protein fused with a red fluorescent protein mCherry, so that Ca2+ sensors conjugated with four N-3-fura-2 dyes with dibenzocyclooctyne (DBCO)-PEG4-biotin as a linker were generated at subcellular compartments in living cells. In cytoplasm, N-3-fura-2 showed a prolonged retention period after binding to scAVD. Furthermore, the reacted N-3-fura-2 was retained inside cells even after free dyes were washed out by methanol fixation. When scAVD was overexpressed on endoplasmic reticulum (ER) membranes, N-3-fura-2 was accumulated on ER membranes. Upon histamine stimulation, which increases cytosolic Ca2+ concentration, ER-localized N-3-fura-2 successfully sensed the Ca2+ level changes at the cytosolic side of ER membrane. Our study demonstrated specific targeting of N-3-fura-2 to subcellular compartments and the ability of sensing focal Ca2+ level changes with the specifically targeted Ca2+ sensors.
    [GRAPHICS]
    .

    DOI PubMed

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    2
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  • Pharmacokinetic Properties of Single and Repeated Injection of Liposomal Platelet Substitute in a Rat Model of Red Blood Cell Transfusion-Induced Dilutional Thrombocytopenia

    Mai Hashimoto, Kazuaki Taguchi, Shigeru Ogaki, Hiroshi Watanabe, Manabu Kinoshita, Kahoko Nishikawa, Shinji Takeoka, Yasuo Ikeda, Makoto Handa, Masaki Otagiri, Toru Maruyama

    JOURNAL OF PHARMACEUTICAL SCIENCES   104 ( 11 ) 3968 - 3976  2015年11月  [査読有り]

     概要を見る

    A preclinical study of dodecapeptide ((400)HHLGGAKQAGDV(411)) (H12)-(adenosine diphosphate, ADP)-liposomes for use as a synthetic platelet (PLT) substitute under conditions of red blood cell (RBC) transfusion-induced dilutional thrombocytopenia is limited to pharmacological effect. In this study, the pharmacokinetics of H12-(ADP)-liposomes in RBC transfusion-induced dilutional thrombocytopenic rats were evaluated. As evidenced by the use of C-14, H-3 double-radiolabeled H12-(ADP)-liposomes in which the encapsulated ADP and liposomal membrane were labeled with C-14 and H-3, respectively, the H12-(ADP)-liposomes remained intact in the blood circulation for up to 3 h after injection, and were mainly distributed to the liver and spleen. The encapsulated ADP was mainly eliminated in the urine, whereas the outer membrane was mainly eliminated in the feces. These successive pharmacokinetic properties of the H12-(ADP)-liposomes in RBC transfusion-induced dilutional thrombocytopenic rats were similar to those in healthy rats, except for the shorter retention time in the circulation. When H12-(ADP)-liposomes were repeatedly injected into RBC transfusion-induced dilutional thrombocytopenic rats at intervals of 5 days at a dose of 10 mg lipids/kg, the second dose of injected H12-(ADP)-liposomes were rapidly cleared from the circulation, namely, via the accelerated blood clearance phenomenon. These novel pharmacokinetic findings provide useful information for the further development of H12-(ADP)-liposomes as a PLT substitute. (c) 2015 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:3968-3976, 2015

    DOI PubMed

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    1
    被引用数
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  • Patchwork Coating of Fragmented Ultra-Thin Films and Their Biomedical Applications in Burn Therapy and Antithrombotic Coating

    Yosuke Okamura, Yu Nagase, Shinji Takeoka

    MATERIALS   8 ( 11 ) 7604 - 7614  2015年11月  [査読有り]

     概要を見る

    We have proposed free-standing centimeter-sized ultra-thin films (nanosheets) for biomedical applications. Such nanosheets exhibit unique properties such as transparency, flexibility, and good adhesiveness. However, they are only easily adhered to broad and flat surfaces due to their dimensions. To this end, we recently proposed an innovative nanomaterial: the nanosheets fragmented into submillimeter-size pieces. Intriguingly, such fragmented nanosheets could be adhered to uneven and irregular surfaces in addition to flat surfaces in a spread-out patchwork manner. We herein review the fabrication procedure and characterization of fragmented nanosheets composed of biodegradable polyesters and thermostable bio-friendly polymers, and their biomedical applications in burn therapy and antithrombotic coating using a patchwork coating.

    DOI PubMed

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    4
    被引用数
    (Scopus)
  • Effect of Repeated Injections of Adenosine Diphosphate-Encapsulated Liposomes Coated with a Fibrinogen γ-Chain Dodecapeptide Developed as a Synthetic Platelet Substitute on Accelerated Blood Clearance in a Healthy and an Anticancer Drug-Induced Thrombocyt

    Taguchi K, Hashimoto M, Ogaki S, Watanabe H, Takeoka S, Ikeda Y, Handa M, Otagiri M, Maruyama T

    Journal of pharmaceutical sciences   104 ( 9 ) 3084 - 3091  2015年09月  [査読有り]

    DOI PubMed

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    3
    被引用数
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  • Establishment of a total liquid ventilation system using saline-based oxygen micro/nano-bubble dispersions in rats

    Kenta Kakiuchi, Kenichi Matsuda, Norikazu Harii, Keitaro Sou, Junko Aoki, Shinji Takeoka

    JOURNAL OF ARTIFICIAL ORGANS   18 ( 3 ) 220 - 227  2015年09月  [査読有り]

     概要を見る

    Micro/nano-bubbles are practical nanomaterials designed to increase the gas content in liquids. We attempted to use oxygen micro/nano-bubble dispersions as an oxygen-rich liquid as a means for total liquid ventilation. To determine the oxygen content in the bubble dispersion, a new method based on a spectrophotometric change between oxy- and deoxy-hemoglobin was established. The oxygen micro/nano-bubble dispersion was supplied to an experimental total ventilation liquid in anesthetic rats. Though the amount of dissolving oxygen was as low as 6 mg/L in physiological saline, the oxygen content in the oxygen micro/nano-bubble dispersion was increased to 45 mg/L. The positive correlation between the oxygen content and the life-saving time under liquid ventilation clearly indicates that the life-saving time is prolonged by increasing the oxygen content in the oxygen micro/nano-bubble dispersion. This is the first report indicating that the oxygen micro/nano-bubbles containing a sufficient amount of oxygen are useful in producing oxygen-rich liquid for the process of liquid ventilation.

    DOI PubMed

    Scopus

    8
    被引用数
    (Scopus)
  • Sustainable antimicrobial effect of silver sulfadiazine-loaded nanosheets on infection in a mouse model of partial-thickness burn injury

    Keisuke Ito, Akihiro Saito, Toshinori Fujie, Keisuke Nishiwaki, Hiromi Miyazaki, Manabu Kinoshita, Daizoh Saitoh, Shinya Ohtsubo, Shinji Takeoka

    ACTA BIOMATERIALIA   24   87 - 95  2015年09月  [査読有り]

     概要を見る

    Partial-thickness burn injury has the potential for reepithelialization and heals within 3 weeks. If the wound is infected by bacteria before reepithelization, however, the depth of disruption increases and the lesion easily progresses to the full-thickness dermal layers. In the treatment of partial-thickness burn injury, it is important to prevent the wound area from bacterial infection with an antimicrobial dressing. Here, we have tested the antimicrobial properties of polymeric ultra-thin films composed of poly(lactic acid) (termed "PLA nanosheets"), which have high flexibility, adhesive strength and transparency, and silver sulfadiazine (AgSD), which exhibits antimicrobial efficacy. The AgSD-loaded nanosheet released Ag+ for more than 3 days, and exerted antimicrobial efficacy against methicillin-resistant Staphylococcus aureus (MRSA) in an in vitro Kirby-Bauer test. By contrast, a cell viability assay indicated that the dose of AgSD used in the PLA nanosheets did not show significant cytotoxicity toward fibroblasts. In vivo evaluation using a mouse model of infection in a partial-thickness burn wound demonstrated that the nanosheet significantly reduced the number of MRSA bacteria on the lesion (more than 10(5)-fold) and suppressed the inflammatory reaction, thereby preventing a protracted wound healing process. (C) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

    DOI PubMed

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    80
    被引用数
    (Scopus)
  • Roll to roll processing of ultraconformable conducting polymer nanosheets

    Zucca, A, Zucca, A, Yamagishi, K, Fujie, T, Fujie, T, Takeoka, S, Takeoka, S, Mattoli, V, Greco, F

    Journal of Materials Chemistry C   3 ( 25 ) 6539 - 6548  2015年07月  [査読有り]

    DOI

  • 衝撃波による致死的肺出血マウスに対する人工血小板(H12‐ADP‐liposome)の救命効果

    萩沢康介, 木下学, 宮脇博基, 佐藤俊一, 鈴木英紀, 土井麻美, 武岡真司, 小野聡, 斎藤大蔵, 西田育弘

    Shock   29 ( 2 ) 1 - 8  2015年02月

    J-GLOBAL

  • Treatment with fibrinogen γ-chain peptide-coated, adenosine 5'-diphosphate-encapsulated liposomes as an infusible hemostatic agent against active liver bleeding in rabbits with acute thrombocytopenia.

    Hagisawa K, Nishikawa K, Yanagawa R, Kinoshita M, Doi M, Suzuki H, Iwaya K, Saitoh D, Seki S, Takeoka S, Handa M, Nishida Y

    Transfusion   55 ( 2 ) 314 - 325  2015年02月  [査読有り]

    DOI PubMed

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    15
    被引用数
    (Scopus)
  • Sustainable antimicrobial effect of silver sulfadiazine-loaded nanosheets on infection in a mouse model of partial-thickness burn injury.

    Ito Keisuke, Saito Akihiro, Fujie Toshinori, Nishiwaki Keisuke, Miyazaki Hiromi, Kinoshita Manabu, Saitoh Daizoh, Ohtsubo Shinya, Takeoka Shinji

    ACTA BIOMATERIALIA   24  2015年  [査読有り]

    DOI PubMed

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    80
    被引用数
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  • A ratiometric fluorescent molecular probe for visualization of mitochondrial temperature in living cells

    Mitsumasa Homma, Yoshiaki Takei, Atsushi Murata, Takafumi Inoue, Shinji Takeoka

    CHEMICAL COMMUNICATIONS   51 ( 28 ) 6194 - 6197  2015年  [査読有り]

     概要を見る

    Mitochondrial thermodynamics is the key to understand cellular activities related to homeostasis and energy balance. Here, we report the first ratiometric fluorescent molecular probe (Mito-RTP) that is selectively localized in the mitochondria and visualize the temperature. We confirmed that Mito-RTP could work as a ratiometric thermometer in a cuvette and living cells.

    DOI PubMed

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    106
    被引用数
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  • A Cu-free clickable fluorescent probe for intracellular targeting of small biomolecules

    Kento Yamagishi, Kazuaki Sawaki, Atsushi Murata, Shinji Takeoka

    CHEMICAL COMMUNICATIONS   51 ( 37 ) 7879 - 7882  2015年  [査読有り]

     概要を見る

    We synthesized a novel cyclooctyne-based clickable fluorescent probe with versatile properties such as high cell-membrane permeability and free diffusibility in the cell. Our probe "FC-DBCO'' was conjugated to an azide-modified mannose via a Cu-free click reaction in living HeLa cells and displayed intracellular specific fluorescence imaging with low background signals.

    DOI PubMed

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    14
    被引用数
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  • Micro-thermography in millimeter-scale animals by using orally-dosed fluorescent nanoparticle thermosensors

    Satoshi Arai, Ferdinandus, Shinji Takeoka, Shin'ichi Ishiwata, Hirotaka Sato, Madoka Suzuki

    ANALYST   140 ( 22 ) 7534 - 7539  2015年  [査読有り]

     概要を見る

    We propose an instant micro-thermography method using a fluorescent-nanoparticle thermosensor capable of reporting temperature as the fluorescence intensity ratio of the temperature-sensitive dye to the reference. We demonstrate "temperature mapping" inside a fruit fly larva that was orally dosed with nanoparticle thermosensors.

    DOI PubMed

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    24
    被引用数
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  • 人工血小板製剤のフロンティア 血小板減少状態における血小板代替物H12(ADP)リポゾームの体内動態解析

    橋本 麻衣, 田口 和明, 大柿 滋, 異島 優, 渡邊 博志, 西川 可穗子, 木下 学, 武岡 真司, 池田 康夫, 半田 誠, 小田切 優樹, 丸山 徹

    人工血液   22 ( 1 ) 27 - 27  2014年11月  [査読有り]

  • Homeotropic alignment of dendritic columnar liquid crystal induced by hydrogen-bonded triphenylene core bearing fluoroalkyl chains.

    Shinsuke Ishihara, Yusuke Furuki, Jonathan P Hill, Katsuhiko Ariga, Shinji Takeoka

    Journal of nanoscience and nanotechnology   14 ( 7 ) 5130 - 7  2014年07月  [査読有り]  [国際誌]

     概要を見る

    A 1:3 molar complex of the fluoroalkyl side chain-substituted 2,6,10-tris-carboxymethoxy-3,7,11-tris(4,4,5,5,6,6,7,7,7-nonafluoroheptyloxy)triphenylene (TPF4) with the second generation dendron 3,5-bis(3,4-bis-dodecyloxybenzyloxy)-N-pyridin-4-yl-benzamide (DN) assembled through complementary hydrogen bonding to form a supramolecular columnar liquid crystal, which exhibited homeotropic alignment when sandwiched between octadecyltrichlorosilane (OTS)-coated or indium tin oxide (ITO)-coated glass plates due to specific interactions between the fluoroalkyl side chains and the substrates.

    DOI PubMed

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    9
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  • Enhanced cellular uptake of maleimide-modified liposomes via thiol-mediated transport

    Tianshu Li, Shinji Takeoka

    International Journal of Nanomedicine   9 ( 1 ) 2849 - 2861  2014年06月  [査読有り]

     概要を見る

    With a small amount of maleimide modification on the liposome surface, enhanced cellular uptake of liposomes and drug-delivery efficiency can be obtained both in vitro and in vivo. Herein, we describe the mechanisms underlying this enhanced cellular uptake. Suppression of the cellular uptake of maleimide-modified liposomes (M-GGLG, composed of 1,5-dihexadecyl N,N-diglutamyl-lysyl-L-glutamate [GGLG]/cholesterol/poly(ethylene glycol) - 1,2-distearoyl-sn-glycero-3-phosphoethanolamine [PEG5000-DSPE]/maleimide [M]-PEG5000-Glu2C18 at a molar ratio of 5:5:0.03:0.03) caused by temperature block and addition of serum was alleviated compared with that of liposomes without maleimide modification (GGLG liposomes, composed of GGLG/cholesterol/PEG5000-DSPE/PEG5000-Glu2C18 at a molar ratio of 5:5:0.03:0.03). When 0.01 nM N-ethylmaleimide was used to pre-block cellular thiols, the cellular uptake of M-GGLG liposomes was decreased to approximately 70% in HeLa, HCC1954, MDA-MB-468, and COS-7 cell lines. Moreover, inhibition of a thiol-related reductase such as protein disulfide isomerase resulted in a 15%-45% inhibition of the cellular uptake of M-GGLG liposomes, whereas GGLG liposomes were not influenced. Further, single and mixed inhibitors of clathrin-mediated endocytosis, caveolae-mediated endocytosis, and macropinocytosis did not efficiently inhibit the cellular uptake of M-GGLG liposomes. Using confocal microscopy, we verified that M-GGLG liposomes were localized partially in lysosomes after inhibition of the mentioned conventional endocytic pathways. Therefore, it was hypothesized that the mechanisms underlying the enhanced cellular uptake of liposomes by maleimide modification was thiol-mediated membrane trafficking, including endocytosis and energy-independent transport. © 2014 Li and Takeoka.

    DOI PubMed

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    49
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  • Periosteum-Mimetic Structures Made from Freestanding Microgrooved Nanosheets

    Xuetao Shi, Toshinori Fujie, Akihiro Saito, Shinji Takeoka, Ying Hou, Yiwei Shu, Mingwei Chen, Hongkai Wu, Ali Khademhosseini

    ADVANCED MATERIALS   26 ( 20 ) 3290 - +  2014年05月  [査読有り]

     概要を見る

    A "sticker-like" PLGA nanosheet with microgrooved patterns is developed through a facile combination of spin coating and micropatterning techniques. The resulting microgrooved PLGA nanosheets can be physically adhered on flat or porous surfaces with excellent stability in aqueous environments and can harness the spatial arrangements of cells, which make it a promising candidate for generating biomimic periosteum for bone regenerative applications.

    DOI PubMed

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  • 抗生剤担持ナノシートを用いた難治性創部細菌感染に対する新規治療戦略(Nobel therapeutic strategy against burn-wound bacterial infection using antibiotic-loaded nanosheet)

    木下 学, 齊藤 晃広, 宮崎 裕美, 藤枝 俊宣, 武岡 真司, 五十嵐 正巳, 中島 正裕, 中島 弘幸, 四ノ宮 成祥, 関 修司

    日本細菌学雑誌   69 ( 1 ) 137 - 137  2014年02月

  • Orbital Shaking Promoted Vascular Elastogenesis in Cultured Rat Aortic Smooth Muscle Cells

    Shiraishi Ryosuke, Iwasaki Kiyotaka, Aida Takashi, Saito Shumpei, Zin Nur Khatijah Mohd, Takeoka Shinji, Umezu Mitsuo, Minamisawa Susumu

    BIOPHYSICAL JOURNAL   106 ( 2 ) 615A  2014年01月  [査読有り]

    DOI

  • Intracellular delivery of universal proteins using a lysine headgroup containing cationic liposomes: Deciphering the uptake mechanism

    Satya Ranjan Sarker, Ryosuke Hokama, Shinji Takeoka

    Molecular Pharmaceutics   11 ( 1 ) 164 - 174  2014年01月  [査読有り]

     概要を見る

    An amino acid-based cationic lipid having a TFA counterion (trifluoroacetic acid counterion) in the lysine headgroup was used to deliver functional proteins into human cervical cancer cells, HeLa, in the presence of serum. Proteins used in the study were fluorescein isothiocyanate (FITC) labeled bovine serum albumin, mouse anti-F actin antibody [NH3], and goat anti mouse IgG conjugated with FITC. The formation of liposome/protein complexes was confirmed using native polyacrylamide gel electrophoresis. Furthermore, the complexes were characterized in terms of their size and zeta potential at different pH values and found to be responsive to changes in pH. The highest delivery efficiency of the liposome/albumin complexes was 99% at 37 °C. The liposomes effectively delivered albumin and antibodies as confirmed by confocal laser scanning microscopy (CLSM). Inhibition studies showed that the cellular uptake mechanism of the complexes was via caveolae-mediated endocytosis, and the proteins were subsequently released from either the early endosomes or the caveosomes as suggested by CLSM. Thus, lysine-based cationic liposomes can be a useful tool for intracellular protein delivery. © 2013 American Chemical Society.

    DOI PubMed

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    40
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  • Enhanced cellular uptake of maleimide-modified liposomes via thiol-mediated transport

    Tianshu Li, Shinji Takeoka

    INTERNATIONAL JOURNAL OF NANOMEDICINE   9   2849 - 2861  2014年  [査読有り]

     概要を見る

    With a small amount of maleimide modification on the liposome surface, enhanced cellular uptake of liposomes and drug-delivery efficiency can be obtained both in vitro and in vivo. Herein, we describe the mechanisms underlying this enhanced cellular uptake. Suppression of the cellular uptake of maleimide-modified liposomes (M-GGLG, composed of 1,5-dihexadecyl N, N-diglutamyl-lysyl-L-glutamate [GGLG]/cholesterol/poly(ethylene glycol) 1,2- distearoyl-sn-glycero-3-phosphoethanolamine [PEG(5000)-DSPE]/maleimide [M]-PEG(5000) -Glu2C(18) at a molar ratio of 5: 5: 0.03: 0.03) caused by temperature block and addition of serum was alleviated compared with that of liposomes without maleimide modification (GGLG liposomes, -composed of GGLG/cholesterol/PEG(5000)-DSPE/PEG(5000)-Glu2C(18) at a molar ratio of 5: 5: 0.03: 0.03). When 0.01 nM N-ethylmaleimide was used to pre-block cellular thiols, the cellular uptake of M-GGLG liposomes was decreased to approximately 70% in HeLa, HCC1954, MDA-MB-468, and COS-7 cell lines. Moreover, inhibition of a thiol-related reductase such as protein disulfide isomerase resulted in a 15%-45% inhibition of the cellular uptake of M-GGLG liposomes, whereas GGLG liposomes were not influenced. Further, single and mixed inhibitors of clathrin-mediated endocytosis, caveolae-mediated endocytosis, and macropinocytosis did not efficiently inhibit the cellular uptake of M-GGLG liposomes. Using confocal microscopy, we verified that M-GGLG liposomes were localized partially in lysosomes after inhibition of the mentioned conventional endocytic pathways. Therefore, it was hypothesized that the mechanisms underlying the enhanced cellular uptake of liposomes by maleimide modification was thiol-mediated membrane trafficking, including endocytosis and energy-independent transport.

    DOI

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    49
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  • A Nanoparticle-Based Ratiometric and Self-Calibrated Fluorescent Thermometer for Single Living Cells

    Yoshiaki Takei, Satoshi Arai, Atsushi Murata, Masao Takabayashi, Kotaro Oyama, Shin'ichi Ishiwata, Shinji Takeoka, Madoka Suzuki

    ACS NANO   8 ( 1 ) 198 - 206  2014年01月  [査読有り]

     概要を見る

    The homeostasis of body temperature and energy balance is one of the major principles in biology. Nanoscale thermometry of aqueous solutions is a challenging but crucial technique to understand the molecular basis of this essential process. Here, we developed a ratiometric nanothermometer (RNT) for intracellular temperature measurement in real time. Both the thermosensitive fluorophore, beta-diketonate chelate europium(III) thenoyltrifluoroacetonate, and the thermoinsensitive fluorophore, rhodamine 101, which was used as a self-reference, are embedded in a polymeric particle that protects the fluorophores from intracellular conditions. The ratiometric measurement of single RNT spots is independent of the displacement of the RNT along the z-axis. The temperature is therefore determined at the location of each RNT under an optical microscope regardless of the dynamic movement of living cells. As a demonstration of the spot-by-spot intracellular thermometry, we successfully followed the temperature change in individual RNT spots in a single cell together with the Ca2+ burst induced by the Ca2+ ionophore ionomycin. The temperature increases differently among different spots, implying heterogeneous heat production in the cell. We then show that, in some spots, the temperature gradually decreases, while in others it remains high. The average temperature elevation within a cell is positively correlated to the increase in Ca2+, suggesting that the activity and/or number of heat sources are dependent on the Ca2+ concentration.

    DOI PubMed

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    179
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  • Cationic amino acid based lipids as effective nonviral gene delivery vectors for primary cultured neurons

    Yumiko Aoshima, Ryosuke Hokama, Keitaro Sou, Satya Ranjan Sarker, Kabuto Iida, Hideki Nakamura, Takafumi Inoue, Shinji Takeoka

    ACS Chemical Neuroscience   4 ( 12 ) 1514 - 1519  2013年12月  [査読有り]

     概要を見る

    The delivery of specific genes into neurons offers a potent approach for treatment of diseases as well as for the study of neuronal cell biology. Here we investigated the capabilities of cationic amino acid based lipid assemblies to act as nonviral gene delivery vectors in primary cultured neurons. An arginine-based lipid, Arg-C3-Glu2C14, and a lysine-based lipid, Lys-C3-Glu2C14, with two different types of counterion, chloride ion (Cl-) and trifluoroacetic acid (TFA -), were shown to successfully mediate transfection of primary cultured neurons with plasmid DNA encoding green fluorescent protein. Among four types of lipids, we optimized their conditions such as the lipid-to-DNA ratio and the amount of pDNA and conducted a cytotoxicity assay at the same time. Overall, Arg-C3-Glu2C14 with TFA- induced a rate of transfection in primary cultured neurons higher than that of Lys-C 3-Glu2C14 using an optimal weight ratio of lipid-to-plasmid DNA of 1. Moreover, it was suggested that Arg-C 3-Glu2C14 with TFA- showed the optimized value higher than that of Lipofectamine2000 in experimental conditions. Thus, Arg-C3-Glu2C14 with TFA- is a promising candidate as a reliable transfection reagent for primary cultured neurons with a relatively low cytotoxicity. © 2013 American Chemical Society.

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    18
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  • A novel application of maleimide for advanced drug delivery: In vitro and in vivo evaluation of maleimide-modified pH-sensitive liposomes

    Tianshu Li, Shinji Takeoka

    International Journal of Nanomedicine   8   3855 - 3866  2013年10月  [査読有り]

     概要を見る

    Maleimide is a stable and easy-to-handle moiety that rapidly and covalently conjugates thiol groups of cysteine residues in proteins or peptides. Herein, we use maleimide to modify the surface of liposomes in order to obtain an advanced drug delivery system. Employing a small amount (0.3 mol%) of maleimide-polyethylene glycol (PEG) to modify the surface of the liposomes M-GGLG-liposomes, composed of 1,5-dihexadecyl N,N-diglutamyl-lysyl-L-glutamate (GGLG)/cholesterol/poly(ethylene glycol) 1,2-distearoyl-sn-glycero-3-phosphoethanolamine (PEG5000-DSPE)/maleimide-PEG5000-Glu2C18 at a molar ratio of 5:5:0.03:0.03, drug delivery efficiency was remarkably improved both in vitro and in vivo compared to unmodified liposomes (GGLG-liposomes, composed of GGLG/cholesterol/PEG5000-DSPE/PEG5000-Glu2C18 at a molar ratio of 5:5:0.03:0.03). Moreover, this modification did not elicit any detectable increase in cytotoxicity. The maleimide-modification did not alter the physical characteristics of the liposomes such as size, zeta potential, pH sensitivity, dispersibility and drug encapsulation efficiency. However, M-GGLG-liposomes were more rapidly (≥2-fold) internalized into HeLa, HCC1954, and MDA-MB-468 cells compared to GGLG-liposomes. In vivo, M-GGLG-liposomes encapsulating doxorubicin (M-GGLG-DOX-liposomes) also showed a more potent antitumor effect than GGLG-DOX-liposomes and the widely used 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC)-DOX-liposomes after two subcutaneous injections around breast cancer tissue in mice. The biodistribution of liposomes in this model was observed using an in vivo imaging system, which showed that M-GGLG-liposomes were present for significantly longer at the injection site compared to GGLG-liposomes. The outstanding biological functions of the maleimide-modified liposomes as a novel drug delivery system make them ideally suited to a wide range of applications. © 2013 Li and Takeoka.

    DOI PubMed

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  • Application of nanosheets as an anti-adhesion barrier in partial hepatectomy

    Daisuke Niwa, Masatsugu Koide, Toshinori Fujie, Nobuhito Goda, Shinji Takeoka

    JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B-APPLIED BIOMATERIALS   101 ( 7 ) 1251 - 1258  2013年10月  [査読有り]

     概要を見る

    Postoperative adhesion often causes serious adverse effects such as bowl obstruction, chronic abdominal pain, pelvic pain, and infertility. We previously reported that a poly-L-lactic acid (PLLA) nanosheet can efficiently seal a surgical incision without scarring. In this report, we examined whether the PLLA nanosheet can form an effective anti-adhesion barrier in partial hepatectomy accompanied by severe hemorrhaging in rats. To evaluate the anti-adhesive property of the nanosheet, the liver wound surface was covered with TachoComb((R)), a well-known hemostat material used in clinical procedures, and then with the PLLA nanosheet. Dressing the wound surface with TachoComb((R)) alone caused severe adhesion with omentum and/or residual parts of the liver. By contrast, combinational usage of TachoComb((R)) and the PLLA nanosheet significantly reduced such adhesion, presumably by inhibiting the permeation of oozing blood cells and the infiltration of fibroblastic cells. Moreover, the nanosheet displayed low permeability against serum proteins as well as cells in vitro, supporting the notion that the PLLA nanosheet has anti-adhesive properties in vivo. These results strongly suggested that the PLLA nanosheet is a promising material for reducing unwanted postoperative adhesion. (c) 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 101B: 1251-1258, 2013.

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  • Pharmacokinetic study of the structural components of adenosine diphosphate-encapsulated liposomes coated with fibrinogen γ-chain dodecapeptide as a synthetic platelet substitute.

    Taguchi K, Ujihira H, Ogaki S, Watanabe H, Fujiyama A, Doi M, Okamura Y, Takeoka S, Ikeda Y, Handa M, Otagiri M, Maruyama T

    Drug metabolism and disposition: the biological fate of chemicals   41 ( 8 ) 1584 - 1591  2013年08月  [査読有り]

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  • Development of Latanoprost-Loaded Biodegradable Nanosheet as a New Drug Delivery System for Glaucoma

    Kenji Kashiwagi, Keisuke Ito, Hiroki Haniuda, Shinya Ohtsubo, Shinji Takeoka

    INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE   54 ( 8 ) 5629 - 5637  2013年08月  [査読有り]

     概要を見る

    PURPOSE. We investigated the IOP reduction and safety of latanoprost-loaded biodegradable nanosheet (LBNS) as a new antiglaucoma drug delivery system (DDS).
    METHODS. We fabricated a 40 nm thick multilayered biodegradable nanosheet that is composed of chitosan and sodium alginate by means of the layer-by-layer method. Latanoprost isopropyl ester was loaded on the nanosheet to prepare 25, 2.5, and 0.25 mu g/cm(2) LBNSs. A nanosheet without latanoprost isopropyl ester (NS) and 0.005% latanoprost ophthalmic solution were prepared as controls. LBNSs or NS was applied to rat cornea, and IOP was monitored for 9 days. Local adverse effects and eye scratching movement also were investigated. The amount of latanoprost acid in aqueous humor and was measured in rabbits.
    RESULTS. The 0.25 mu g/cm(2) LBNS and 0.005% latanoprost ophthalmic solution showed significant IOP reduction only for 1 day after application, whereas the IOP reduction rates of 2.5 mu g/cm(2) LBNS at 1, 2, 4, 7, and 9 days after application were -27.0% +/- 14.8%, -22.0% +/- 16.7%, -25.8% +/- 18.0%, -22.7% +/- 20.9%, and -6.6% +/- 17.0%, respectively. The 25 mu g/cm(2) LBNS reduced IOP in a similar manner. The 25 mu g/cm(2) LBNS induced transient hyperemia, whereas the 0.25 and 2.5 mu g/cm(2) LBNSs did not exert any local adverse effects. The eye scratching movement test showed that application of 25 mu g/cm(2) LBNS did not cause any irritation of the eye. Latanoprost acid was detected in aqueous humor up to 6 days after application of 2.5 mu g/cm(2) LBNS.
    CONCLUSIONS. LBNS may be used as a novel antiglaucoma DDS.

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  • Effective control of massive venous bleeding by "multioverlapping therapy" using polysaccharide nanosheets in a rabbit inferior vena cava injury model.

    Kohsuke Hagisawa, Akihiro Saito, Manabu Kinoshita, Toshinori Fujie, Naoki Otani, Satoshi Shono, Young-Kwang Park, Shinji Takeoka

    Journal of vascular surgery. Venous and lymphatic disorders   1 ( 3 ) 289 - 97  2013年07月  [査読有り]  [国際誌]

     概要を見る

    OBJECTIVE: To investigate the efficacy of multioverlapping therapy using a polysaccharide nanosheet having 75-nm thickness for sealing and stopping massive venous hemorrhage. METHODS: The hydrostatic durability of the polysaccharide nanosheet was evaluated in vitro when secured to an incised silicon tube. For in vivo studies, the inferior vena cava (IVC) of rabbits was cut longitudinally, and multiple polysaccharide nanosheets were overlapped onto the injured IVC. RESULTS: The mechanical hydrostatic durability of the nanosheets was gradually augmented by an increasing number of multilayered nanosheets in vitro. This durability was saturated at 80 ± 6 mm Hg by four layers of nanosheets, which was robust enough to seal injured vessel walls of the large IVC. Multioverlapping therapy using nanosheets effectively sealed and stopped bleeding from the injured IVC in vivo. One month later, no inflammatory tissue response was observed around the nanosheet attachment sites of the IVC, while conventional suturing repair in control rabbits showed a severe inflammatory response around the sutured area. CONCLUSIONS: The multioverlapping therapy using the polysaccharide nanosheets will effectively stop massive venous bleeding without adverse effects in the immediate or chronic postoperative setting.

    DOI PubMed

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  • [Development of nanoparticle for coagulant].

    Okamura Y, Takeoka S

    Nihon Jibiinkoka Gakkai kaiho   116 ( 6 ) 673 - 678  2013年06月  [査読有り]

     概要を見る

    血小板は, 血液凝固系と連動した巧妙かつ複雑な止血機構を有しており, これらすべての機能を人工系で模倣することは非現実的といっても過言ではない. 感染の危険性がなく長期間保存可能な血小板代替物として, 生体投与可能なナノ粒子に活性化血小板を認識できる分子 (フィブリノーゲンγ鎖C末端ドデカペプチド, HHLGGAKQAGDV: H12) を担持させることで, それが血管損傷部位へ特異的に集積して血栓形成を誘導する起点となり, 集積したナノ粒子によって出血部位を充填し止血能を補助できるとの発想に基づいて, 極めて単純な血小板代替物を設計した. さらに, 血小板凝集を惹起するアデノシン5-二リン酸 (ADP) をリポソームの内水相に封入することで止血能を増幅させることにも成功している.

    DOI PubMed CiNii

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  • Arginine-based cationic liposomes for efficient in vitro plasmid DNA delivery with low cytotoxicity

    Satya Ranjan Sarker, Yumiko Aoshima, Ryosuke Hokama, Takafumi Inoue, Keitaro Sou, Shinji Takeoka

    International Journal of Nanomedicine   8   1361 - 1375  2013年04月  [査読有り]

     概要を見る

    Background: Currently available gene delivery vehicles have many limitations such as low gene delivery efficiency and high cytotoxicity. To overcome these drawbacks, we designed and synthesized two cationic lipids comprised of n-tetradecyl alcohol as the hydrophobic moiety, 3-hydrocarbon chain as the spacer, and different counterions (eg, hydrogen chloride [HCl] salt or trifluoroacetic acid [TFA] salt) in the arginine head group. Methods: Cationic lipids were hydrated in 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) buffer to prepare cationic liposomes and characterized in terms of their size, zeta potential, phase transition temperature, and morphology. Lipoplexes were then prepared and characterized in terms of their size and zeta potential in the absence or presence of serum. The morphology of the lipoplexes was determined using transmission electron microscopy and atomic force microscopy. The gene delivery efficiency was evaluated in neuronal cells and HeLa cells and compared with that of lysine-based cationic assemblies and Lipofectamine™ 2000. The cytotoxicity level of the cationic lipids was investigated and compared with that of Lipofectamine™ 2000. Results: We synthesized arginine-based cationic lipids having different counterions (ie, HCl-salt or TFA-salt) that formed cationic liposomes of around 100 nm in size. In the absence of serum, lipoplexes prepared from the arginine-based cationic liposomes and plasmid (p) DNA formed large aggregates and attained a positive zeta potential. However, in the presence of serum, the lipoplexes were smaller in size and negative in zeta potential. The morphology of the lipoplexes was vesicular. Arginine-based cationic liposomes with HCl-salt showed the highest transfection efficiency in PC-12 cells. However, arginine-based cationic liposomes with TFA salt showed the highest transfection efficiency in HeLa cells, regardless of the presence of serum, with very low associated cytotoxicity. Conclusion: The gene delivery efficiency of amino acid-based cationic assemblies is influenced by the amino acids (ie, arginine or lysine) present as the hydrophilic head group and their associated counterions. © 2013 Sarker et al, publisher and licensee Dove Medical Press Ltd.

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  • Tapping-mode AFM study of tip-induced polymer deformation under geometrical confinement

    Hong Zhang, Yukio Honda, Shinji Takeoka

    Langmuir   29 ( 5 ) 1333 - 1339  2013年02月  [査読有り]

     概要を見る

    The morphological stability of polymer films is critically important to their application as functional materials. The deformation of polymer surfaces on the nanoscale may be significantly influenced by geometrical confinement. Herein, we constructed a mechanically heterogeneous polymer surface by phase separation in a thin polymer film and investigated the deformation behavior of its nanostructure (∼30 nm thickness and ∼100 nm average diameter) with tapping-mode atomic force microscopy. By changing different scan parameters, we could induce deformation localized to the nanostructure in a controllable manner. A quantity called the deformation index is defined and shown to be correlated to energy dissipation by tip-sample interaction. We clarified that the plastic deformation of a polymer on the nanoscale is energy-dependent and is related to the glass-to-rubber transition. The mobility of polymer chains beneath the tapping tip is enhanced, and in the corresponding region a rubberlike deformation with the lateral motion of the tip is performed. The method we developed can provide insight into the geometrical confinement effects on polymer behavior. © 2013 American Chemical Society.

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    11
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  • Application of poly-l-lactic acid nanosheet as a material for wound dressing

    Shimpo Aoki, Manabu Kinoshita, Hiromi Miyazaki, Akihiro Saito, Toshinori Fujie, Keiichi Iwaya, Shinji Takeoka, Daizoh Saitoh

    Plastic and Reconstructive Surgery   131 ( 2 ) 236 - 240  2013年02月  [査読有り]

     概要を見る

    The authors evaluated the efficacy of an ultrathin nanosheet consisting of poly-L-lactic acid (75 nm thick) as a wound dressing material. A full-thickness skin defect was made on the backs of mice and overlapped with or without the poly-L-lactic acid nanosheet. Wound healing was more rapidly improved by overlapping with the nanosheet, especially in the early healing period (at 4 to 6 days). The remaining wound area in the treatment group was significantly smaller at 4 days than in the control group. Histologically, a clear layer was observed over the granulation layer by the nanosheet therapy at 4 days. Thus, overlapping therapy with the poly-L-lactic acid nanosheet accelerated wound healing and formed a clear layer just above the granulation tissue. The poly-L-lactic acid nanosheet may have potential as a novel wound dressing to promote wound healing. Copyright © 2013 by the American Society of Plastic Surgeons.

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  • Novel therapeutic use of polysaccharide nanosheets for arachnoid plasty and enhancement of venous tensile strength in rat microneurosurgery

    Naoki Otani, Manabu Kinoshita, Toshinori Fujie, Akihiro Saito, Shinji Takeoka, Daizoh Saitoh, Kohsuke Hagisawa, Hiroshi Nawashiro, Katsuji Shima

    JOURNAL OF CLINICAL NEUROSCIENCE   20 ( 2 ) 295 - 299  2013年02月  [査読有り]

     概要を見る

    Subdural effusion sometimes occurs during neurosurgery after opening the Sylvian fissure, due to cerebrospinal fluid (CSF) leakage from the torn arachnoid membrane. Unexpected bleeding from the fragile bridging veins may also result from brain retraction. Neurosurgeons must always watch carefully for these complications during surgery. To prevent such complications, we have attempted the clinical application of a polysaccharide nanosheet that is semi-absorbent and has a potent physical adhesive strength to investigate its therapeutic utility for arachnoid plasty and enhancement of bridging vein tensile strength in Sprague-Dawley rats. The use of overlapping nanosheets completely prevented CSF leakage from injured arachnoid membranes in the cerebral cortex. No inflammatory infiltration was observed on the cerebral surface after 6 months of follow up. In addition, the use of nanosheet bandages significantly reinforced venous tensile strength. This reinforcement increased with the number of overlaid nanosheets. We report that polysaccharide nanosheets can be used for arachnoid plasty without chemical bonding agents and for reinforcement of venous tensile strength in rat vessels. Nanosheets may be an effective neurosurgical tool. (C) 2012 Elsevier Ltd. All rights reserved.

    DOI PubMed

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    5
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  • A novel application of maleimide for advanced drug delivery: in vitro and in vivo evaluation of maleimide-modified pH-sensitive liposomes

    Tianshu Li, Shinji Takeoka

    INTERNATIONAL JOURNAL OF NANOMEDICINE   8   3855 - 3866  2013年  [査読有り]

     概要を見る

    Maleimide is a stable and easy-to-handle moiety that rapidly and covalently conjugates thiol groups of cysteine residues in proteins or peptides. Herein, we use maleimide to modify the surface of liposomes in order to obtain an advanced drug delivery system. Employing a small amount (0.3 mol%) of maleimide-polyethylene glycol (PEG) to modify the surface of the liposomes M-GGLG-liposomes, composed of 1,5-dihexadecyl N,N-diglutamyl-lysyl-L-glutamate (GGLG)/cholesterol/poly(ethylene glycol) 1,2-distearoyl-sn-glycero-3-phosphoethanolamine (PEG(5000)-DSPE)/maleimide-PEG(5000)-Glu2C(18) at a molar ratio of 5:5:0.03:0.03, drug delivery efficiency was remarkably improved both in vitro and in vivo compared to unmodified liposomes (GGLG-liposomes, composed of GGLG/cholesterol/PEG(5000)-DSPE/PEG(5000)-Glu2C(18) at a molar ratio of 5: 5: 0.03: 0.03). Moreover, this modification did not elicit any detectable increase in cytotoxicity. The maleimide-modification did not alter the physical characteristics of the liposomes such as size, zeta potential, pH sensitivity, dispersibility and drug encapsulation efficiency. However, M-GGLG-liposomes were more rapidly (&gt;= 2-fold) internalized into HeLa, HCC1954, and MDA-MB-468 cells compared to GGLG-liposomes. In vivo, M-GGLG-liposomes encapsulating doxorubicin (M-GGLG-DOX-liposomes) also showed a more potent antitumor effect than GGLG-DOX-liposomes and the widely used 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC)-DOX-liposomes after two subcutaneous injections around breast cancer tissue in mice. The biodistribution of liposomes in this model was observed using an in vivo imaging system, which showed that M-GGLG-liposomes were present for significantly longer at the injection site compared to GGLG-liposomes. The outstanding biological functions of the maleimide-modified liposomes as a novel drug delivery system make them ideally suited to a wide range of applications.

    DOI

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  • Arginine-based cationic liposomes for efficient in vitro plasmid DNA delivery with low cytotoxicity

    Satya Ranjan Sarker, Yumiko Aoshima, Ryosuke Hokama, Takafumi Inoue, Keitaro Sou, Shinji Takeoka

    INTERNATIONAL JOURNAL OF NANOMEDICINE   8   1361 - 1375  2013年  [査読有り]

     概要を見る

    Background: Currently available gene delivery vehicles have many limitations such as low gene delivery efficiency and high cytotoxicity. To overcome these drawbacks, we designed and synthesized two cationic lipids comprised of n-tetradecyl alcohol as the hydrophobic moiety, 3-hydrocarbon chain as the spacer, and different counterions (eg, hydrogen chloride [HCl] salt or trifluoroacetic acid [TFA] salt) in the arginine head group.
    Methods: Cationic lipids were hydrated in 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) buffer to prepare cationic liposomes and characterized in terms of their size, zeta potential, phase transition temperature, and morphology. Lipoplexes were then prepared and characterized in terms of their size and zeta potential in the absence or presence of serum. The morphology of the lipoplexes was determined using transmission electron microscopy and atomic force microscopy. The gene delivery efficiency was evaluated in neuronal cells and HeLa cells and compared with that of lysine-based cationic assemblies and Lipofectamine (TM) 2000. The cytotoxicity level of the cationic lipids was investigated and compared with that of Lipofectamine (TM) 2000.
    Results: We synthesized arginine-based cationic lipids having different counterions (ie, HCl-salt or TFA-salt) that formed cationic liposomes of around 100 nm in size. In the absence of serum, lipoplexes prepared from the arginine-based cationic liposomes and plasmid (p) DNA formed large aggregates and attained a positive zeta potential. However, in the presence of serum, the lipoplexes were smaller in size and negative in zeta potential. The morphology of the lipoplexes was vesicular. Arginine-based cationic liposomes with HCl-salt showed the highest transfection efficiency in PC-12 cells. However, arginine-based cationic liposomes with TFA salt showed the highest transfection efficiency in HeLa cells, regardless of the presence of serum, with very low associated cytotoxicity.
    Conclusion: The gene delivery efficiency of amino acid-based cationic assemblies is influenced by the amino acids (ie, arginine or lysine) present as the hydrophilic head group and their associated counterions.

    DOI

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    30
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  • 止血能を有するナノ粒子(血小板代替物)の開発と現状

    岡村 陽介, 武岡 真司

    日本耳鼻咽喉科学会会報   116   673 - 678  2013年

  • Drift and fluctuating motion of artificial platelets during the lateral transport and adhesion process near the wall.

    Tobimatsu, H, Paragon, A, Okamura, Y, Takeoka, S, Sudo, R, Ikeda, Y, Tanishita, K

    J. Biorheol.   26   11 - 20  2013年  [査読有り]

  • Fragmentation of Poly(lactic acid) Nanosheets and Patchwork Treatment for Burn Wounds

    Yosuke Okamura, Koki Kabata, Manabu Kinoshita, Hiromi Miyazaki, Akihiro Saito, Toshinori Fujie, Shinya Ohtsubo, Daizoh Saitoh, Shinji Takeoka

    ADVANCED MATERIALS   25 ( 4 ) 545 - 551  2013年01月  [査読有り]

     概要を見る

    Freestanding poly(L-lactic acid) (PLLA) nanosheets are mass-produced by a simple combination of a spin-coating-assisted multi-layering process and a peeling technique. The resulting PLLA nanosheets are fragmented by homogenization and then reconstructed into a "patchwork" sheet on various surfaces without any adhesive reagents. The patchwork is shown to offer excellent protection against burn wound infection with Pseudomonas aeruginosa, and may therefore be an alternative to conventional burn therapy for prevention of infection.

    DOI PubMed

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    64
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  • Selective Molecular Permeability Induced by Glass Transition Dynamics of Semicrystalline Polymer Ultrathin Films

    Toshinori Fujie, Yuko Kawamoto, Hiroki Haniuda, Akihiro Saito, Koki Kabata, Yukio Honda, Eriko Ohmori, Toru Asahi, Shinji Takeoka

    MACROMOLECULES   46 ( 2 ) 395 - 402  2013年01月

     概要を見る

    Most polymers solidify below a glass transition temperature (;), which is important for the fabrication of polymeric materials. The glass transition dynamics (GTD) of polymers alters their physical properties and therefore the range of applications suitable for the particular materials. In this regard, most GTD studies were oriented to the thermodynamics of amorphous polymer systems, while little studies were known for semicrystalline polymers. Here, we focus on the glassy and crystalline properties of semicrystalline polymers such as poly(L-lactic acid) (PLLA) and envisage to control the nanostructure of free-standing PLLA ultrathin films (referred as "PLLA nanosheets"), via thermodynamic rearrangement of polymer chains entangled in a quasi-two-dimensional interface during the GTD process. The annealing process on the PLLA nanosheets (&lt;100 nm thick) resulted in the formation of semicrystalline domains and microscopic apertures with polymer chains (similar to 100 nm in size). Such nanostructure surprisingly induced selective molecular permeability, which was controlled as a function of film thickness and inherent crystallinity. The present methodology demonstrates the direct conversion of thermodynamic properties of semicrystalline polymers into the functional nanostructured polymeric materials.

    DOI

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    24
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  • Intracellular click reaction with a fluorescent chemical Ca2+ indicator to prolong its cytosolic retention

    Yoshiaki Takei, Atsushi Murata, Kento Yamagishi, Satoshi Arai, Hideki Nakamura, Takafumi Inoue, Shinji Takeoka

    CHEMICAL COMMUNICATIONS   49 ( 66 ) 7313 - 7315  2013年  [査読有り]

     概要を見る

    The powerful strategy of "intracellular click reaction" was used to retain a chemical Ca2+ indicator in the cytosol. Specifically, a novel clickable Ca2+ indicator "N-3-fura-2 AM" was coupled with dibenzylcyclooctyl-modified biomacromolecules via copper-free click reaction in living cells and Ca2+ oscillation was observed for an extended period of time.

    DOI PubMed

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    7
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  • Pharmacokinetic study of adenosine diphosphate-encapsulated liposomes coated with fibrinogen γ-chain dodecapeptide as a synthetic platelet substitute in an anticancer drug-induced thrombocytopenia rat model.

    Taguchi K, Ujihira H, Watanabe H, Fujiyama A, Doi M, Takeoka S, Ikeda Y, Handa M, Otagiri M, Maruyama T

    Journal of pharmaceutical sciences   102 ( 10 ) 3852 - 3859  2013年  [査読有り]

    DOI PubMed

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    7
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  • Novel therapeutic use of polysaccharide nanosheets for arachnoid plasty and enhancement of venous tensile strength in rat microneurosurgery

    Naoki Otani, Manabu Kinoshita, Toshinori Fujie, Akihiro Saito, Shinji Takeoka, Daizoh Saitoh, Kohsuke Hagisawa, Hiroshi Nawashiro, Katsuji Shima

    Journal of Clinical Neuroscience Corresponding   20 ( 2 ) 301 - 305  2012年12月

    DOI

  • Ability of fibrinogen γ-derived dodecapeptides with different sequences to bind to rat platelets

    Koji Tokutomi, Toshiaki Tagawa, Maki Korenaga, Masatoshi Chiba, Tomohiro Asai, Naohide Watanabe, Shinji Takeoka, Makoto Handa, Yasuo Ikeda, Naoto Oku

    International Journal of Pharmaceutics   438 ( 1-2 ) 296 - 301  2012年11月  [査読有り]

    DOI PubMed

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    2
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  • Fibrinogen γ-chain peptide-coated, adenosine diphosphate-encapsulated liposomes rescue thrombocytopenic rabbits from non-compressible liver hemorrhage

    Nishikawa K, Hagisawa K, Kinoshita M, Shono S, Katsuno S, Doi M, Yanagawa R, Suzuki H, Iwaya K, Saitoh D, Sakamoto T, Seki S, Takeoka S, Handa M

    Journal of Thrombosis and Haemostasis   10 ( 10 ) 2137 - 2148  2012年10月

    DOI

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    26
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  • Coordinative Nanoporous Polymers Synthesized with Hydrogen-Bonded Columnar Liquid Crystals

    Shinsuke Ishihara, Yusuke Furuki, Jonathan P. Hill, Katsuhiko Ariga, Shinji Takeoka

    JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY   12 ( 10 ) 7885 - 7895  2012年10月  [査読有り]

     概要を見る

    In this paper, we report the development of nanoporous polymer which demonstrates the coordination property toward zinc porphyrin. A hydrogen-bonded columnar liquid crystalline precursor composed of a triphenylene template and three equivalent of the surrounding dendric amphiphile bearing a pyridyl head group and a polymerizable aliphatic chain, was covalently fixed by photo-polymerization, and then the subsequent selective removal of the template successively resulted in a nanoporous polymer in which the pore wall is modified with pyridyl groups. The nanoporous polymer reflected the conformation of template, and displayed considerable coordination ability of the pyridyl groups towards zinc porphyrin. The coordinative nanoporous polymer is promising as a nano-scaled scaffold for the organization of dyes into functional supramolecular architectures.

    DOI PubMed

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    5
    被引用数
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  • Heterofunctional nanosheet controlling cell adhesion properties by collagen coating

    Daisuke Niwa, Toshinori Fujie, Thorsten Lang, Nobuhito Goda, Shinji Takeoka

    JOURNAL OF BIOMATERIALS APPLICATIONS   27 ( 2 ) 131 - 141  2012年08月

     概要を見る

    Recently, biomaterials have been widely used in a variety of medical applications. We previously reported that a poly-l-lactic acid (PLLA) nanosheet shows anti-adhesive properties and constitutes a useful biomaterial for preventing unwanted wound adhesion in surgical operations. In this article, we examine whether the PLLA nanosheet can be specifically modified with biomacromolecules on one surface only. Such an approach would endow each side of the nanosheet with discrete functions, that is anti-adhesive and pro-healing properties. We fabricated two distinct PLLA nanosheets: (i) collagen cast on the surface of a PLLA nanosheet (Col-Cast-PLLA) and (ii) collagen spin-coated on the nanosheet (Col-Spin-PLLA). In the Col-Spin-PLLA nanosheet, the collagen layer had a thickness of 5-10 nm on the PLLA surface and displayed increased hydrophilicity compared to both PLLA and Col-Cast-PLLA nanosheets. In addition, atomic force microscopy showed disorganized collagen fibril formation on the PLLA layer when covered using the spin-coating method, while apparent bundle formations of collagen were formed in the Col-Cast-PLLA nanosheet. The Col-Spin-PLLA nanosheet provided a microenvironment for cells to adhere and spread. By contrast, the Col-Cast-PLLA nanosheet displayed reduced cell adhesion compared to the Col-Spin-PLLA nanosheet. Consistent with these findings, immunocytochemical analysis clearly showed fine networks of actin filaments in cells cultured on the Col-Spin-PLLA, but not the Col-Cast-PLLA nanosheet. Therefore, the Col-Spin-PLLA nanosheet was shown to be more suitable for acting as a scaffold. In conclusion, we have succeeded in developing a heterofunctional nanosheet comprising a collagen modified side, which has the ability to rapidly adhere cells, and an unmodified side, which acts as an adhesion barrier, by using a spin-coating technique.

    DOI

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    23
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  • Therapeutic efficacy of an antibiotic-loaded nanosheet in a murine burn-wound infection model

    Akihiro Saito, Hiromi Miyazaki, Toshinori Fujie, Shinya Ohtsubo, Manabu Kinoshita, Daizoh Saitoh, Shinji Takeoka

    ACTA BIOMATERIALIA   8 ( 8 ) 2932 - 2940  2012年08月  [査読有り]

     概要を見る

    Polymeric ultra-thin films (nanosheets) possess unique properties that make them suitable materials for various biomedical applications. In our previous study, we assessed the use of an antibiotic (tetracycline, TC)-loaded nanosheet (or "TC-nanosheet") for the treatment of gastrointestinal tissue defects. The nanosheet consisted of three functional layers: layer-by-layer nanosheet as a stable platform, TC as an antimicrobial agent with autofluorescence for tracing, and a poly(vinyl acetate) nanosheet to act as a protecting layer. The TC-nanosheet has high flexibility, adhesive strength and transparency. Here, we evaluated the effectiveness of the TC-nanosheet in preventing full thickness burn-wound infections. In an in vivo study, murine dorsal skin was injured by full-thickness burns and then infected with Pseudomonas aeruginosa (P. aeruginosa), a common bacterium causing burn-associated infections. The wound site was treated either with a TC-nanosheet, TC-unloaded nanosheet or left untreated. Wound management was facilitated by the high transparency of the TC-nanosheet. The TC-nanosheet significantly improved burn-wound infection by P. aeruginosa in mice. Indeed, all mice treated with the TC-nanosheet survived, whereas the other treatment groups displayed increased rates of mortality due to bacterial infection. According to histological analyses and viable bacterial counting in the liver (bacterial translocation), the TC-nanosheets were able to prevent not only the local inflammation but also systemic inflammation. We conclude that the TC-nanosheet can act as an effective treatment for full-thickness burn-wound infection. Hence, the TC-nanosheet is a promising therapeutic tool for burn-wound management in severely burn-injured patients. (c) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

    DOI PubMed

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    47
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  • Mass Spectrometric Screening of Ligands with Lower Off-Rate from a Clicked-Based Pooled Library

    Satoshi Arai, Shota Hirosawa, Yusuke Oguchi, Madoka Suzuki, Atsushi Murata, Shin'ichi Ishiwata, Shinji Takeoka

    ACS COMBINATORIAL SCIENCE   14 ( 8 ) 451 - 455  2012年08月  [査読有り]

     概要を見る

    This paper describes a convenient screening method using ion trap electrospray ionization mass spectrometry to classify ligands to a target molecule in terms of kinetic parameters. We demonstrate this method in the screening of ligands to a hexahistidine tag from a pooled library synthesized by click chemistry. The ion trap mass spectrometry analysis revealed that higher stabilities of ligand-target complexes in; the gas phase were related to lower dissociation rate constants, i.e., off-rates in solution. Finally, we prepared a fluorescent probe utilizing the ligand with lowest off-rate and succeeded in performing single molecule observations of hexahistidine-tagged myosin V walking on actin filaments.

    DOI PubMed

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    2
    被引用数
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  • An ultrathin poly(L-lactic acid) nanosheet as a burn wound dressing for protection against bacterial infection

    Hiromi Miyazaki, Manabu Kinoshita, Akihiro Saito, Toshinori Fujie, Koki Kabata, Etsuko Hara, Satoshi Ono, Shinji Takeoka, Daizoh Saitoh

    WOUND REPAIR AND REGENERATION   20 ( 4 ) 573 - 579  2012年07月  [査読有り]

     概要を見る

    Burn wounds are highly susceptible to bacterial infection due to impairment of the skin's integrity. Therefore, prevention of bacterial colonization/infection in the wound is crucial for the management of burns, including partial-thickness burn injuries. Although partial-thickness burn injuries still retain the potential for reepithelialization, the complication of wound infection severely impairs the reepithelialization even in such superficial burn injuries. We recently developed a biocompatible nanosheet consisting of poly(l-lactic acid) (PLLA). The PLLA nanosheets have many useful and advantageous biological properties for their application as a wound dressing, such as sufficient flexibility, transparency, and adhesiveness. We herein investigated the suitability of the PLLA nanosheets as a wound dressing for partial-thickness burn wounds in mice. The PLLA nanosheets tightly adhered to the wound without any adhesive agents. Although wound infection with Pseudomonas aeruginosa in the controls significantly impaired reepithelialization of burn wounds, dressing with the PLLA nanosheet markedly protected against bacterial wound infection, thereby improving wound healing in the mice receiving partial-thickness burn injuries. The PLLA nanosheet also showed a potent barrier ability for protecting against bacterial penetration in vitro. The ultrathin PLLA nanosheet may be applied as a protective dressing to reduce environmental contamination of bacteria in a partial-thickness burn wound.

    DOI PubMed

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    37
    被引用数
    (Scopus)
  • Morphological Evolution within Spin-Cast Ultrathin Polymer Blend Films Clarified by a Freestanding Method

    Hong Zhang, Shinji Takeoka

    MACROMOLECULES   45 ( 10 ) 4315 - 4321  2012年05月

     概要を見る

    Polymer phase separation has established a series of bottom-up nanofabrication methods. Owing to the intrinsic immiscibility of most polymer blends, phase separation is typically produced by rapid quenching during spin-casting. However, the full sequence of events that occur during this process is still unclear, especially in the case of ultrathin polymer blend films. Herein, a freestanding method is first introduced to obtain morphological information from the bottom side of the film. We demonstrate that when the thickness of ultrathin film is comparable to the dimensional scale of the phase separation domains, it is feasible to prepare perforated films with uniform nanopores via selective solvent etching. Our results also provide direct evidence that the spinodal decomposition mechanism plays an important role in determining the final morphology within the ultrathin polymer blend films. These findings are of practical value in the fabrication of desired nanostructures by polymer phase separation.

    DOI

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    28
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  • Evaluation of the influence of ionization states and spacers in the thermotropic phase behaviour of amino acid-based cationic lipids and the transfection efficiency of their assemblies

    Satya Ranjan Sarker, Satoshi Arai, Motohide Murate, Hiroshi Takahashi, Masaki Takata, Toshihide Kobayashi, Shinji Takeoka

    International Journal of Pharmaceutics   422 ( 1-2 ) 364 - 373  2012年01月

     概要を見る

    The influence of both the ionization states and the hydrocarbon chain spacer of a series of amino acid-based cationic lipids was evaluated in terms of gene delivery efficiency and cytotoxicity to the COS-7 cell line and compared with that of Lipofectamine™ 2000. We synthesized a series of amino acid-based cationic lipids with different ionization states (i.e., -NH 2, -NH 3+Cl - or -NH 3+TFA -) in the lysine head group and different hydrocarbon chain spacers (i.e., 0, 3, 5 or 7 carbon atoms) between the hydrophilic head group and hydrophobic moieties. In the 3-carbon series, the cationic assemblies formed a micellar structure in the presence of -NH 3+Cl - and a vesicular structure both in the presence of -NH 2 and -NH 3+TFA -. Differential scanning calorimetry (DSC) data revealed a significantly lower (8.1°C) gel-to-liquid crystalline phase transition temperature for cationic assemblies bearing -NH 3+TFA - when compared to their -NH 2 counterparts. Furthermore, the zeta potential of cationic assemblies having -NH 3+TFA - in the hydrophilic head group was maximum followed by -NH 3+Cl - and -NH 2 irrespective of their hydrocarbon chain spacer length. The gene delivery efficiency in relation to the ionization states of the hydrophilic head group was as follows: -NH 3+TFA - > -NH 3+Cl - > -NH 2. © 2011 Elsevier B.V.

    DOI PubMed

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    26
    被引用数
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  • Walking nanothermometers: spatiotemporal temperature measurement of transported acidic organelles in single living cells

    Kotaro Oyama, Masao Takabayashi, Yoshiaki Takei, Satoshi Arai, Shinji Takeoka, Shin'ichi Ishiwata, Madoka Suzuki

    LAB ON A CHIP   12 ( 9 ) 1591 - 1593  2012年

     概要を見る

    We fabricated fluorescent nanoparticles which monitor temperature changes without sensitivity to pH (4-10) and ionic strength (0-500 mM). The nanothermometers spontaneously enter living HeLa cells via endocytosis, enclosed in acidic organelles, i.e., endosome/lysosome, and then transported along microtubules in a temperature-dependent manner, working as "walking nanothermometers".

    DOI

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    81
    被引用数
    (Scopus)
  • A TEMPO-conjugated fluorescent probe for monitoring mitochondrial redox reactions

    Shota Hirosawa, Satoshi Arai, Shinji Takeoka

    CHEMICAL COMMUNICATIONS   48 ( 40 ) 4845 - 4847  2012年  [査読有り]

     概要を見る

    We report a mitochondrial targeted redox probe (MitoRP) that comprises a nitroxide radical (TEMPO) moiety and coumarin 343. Using isolated mitochondria in the presence/absence of substrates and inhibitors of oxidative phosphorylation, we demonstrated that MitoRP is a useful probe to monitor the electron flow associated with complex I.

    DOI PubMed

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    56
    被引用数
    (Scopus)
  • 高分子系ナノシートの外科手術用創傷被覆材、癒着防止剤としての可能性

    武岡 真司, 藤枝 俊宣

    MATERIAL STAGE   12 ( 7 ) 16 - 19  2012年

    CiNii

  • 同種皮膚マイクロスキングラフティングによる新規熱傷治療法の基礎研究

    宮﨑裕美, 永野穂高, 野原良介, 木下 学, 齋藤晃広, 小野 聡, 武岡真司, 齋藤大蔵

    熱傷   38 ( 1 ) 31 - 38  2012年

  • 生体投与可能なナノ構造体の構築と血小板代替物への応用

    岡村陽介, 武岡真司

    人工血液   20 ( 2 ) 38 - 47  2012年

  • Ultrastructural analysis of thrombin-induced interaction between human platelets and liposomes carrying fibrinogen γ-chain dodecapeptide as a synthetic platelet substitute

    Hidenori Suzuki, Yosuke Okamura, Yasuo Ikeda, Shinji Takeoka, Makoto Handa

    Thrombosis Research   128 ( 6 ) 552 - 559  2011年12月

    DOI

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    11
    被引用数
    (Scopus)
  • カチオン性アミノ酸型脂質リポソームによる神経細胞への遺伝子導入の評価

    青島 由美子, Ranjan Sarker Satya, 井上 貴文, 武岡 真司

    日本バイオマテリアル学会大会予稿集   33回   213 - 213  2011年11月  [査読有り]

  • Novel technique of overlaying a poly-l-lactic acid nanosheet for adhesion prophylaxis and fixation of intraperitoneal onlay polypropylene mesh in a rabbit model

    Keiichi Fujino, Manabu Kinoshita, Akihiro Saitoh, Hidekazu Yano, Kahoko Nishikawa, Toshinori Fujie, Keiichi Iwaya, Minoru Kakihara, Shinji Takeoka, Daizoh Saitoh, Yuji Tanaka

    SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES   25 ( 10 ) 3428 - 3436  2011年10月

     概要を見る

    Background One problem with polypropylene mesh (PPM) used to repair abdominal wall hernias is dense adhesions to the visceral surface. The authors developed the biocompatible poly-l-lactic acid (PLLA) nanosheet (thickness &lt; 100 nm), which has the unique ability to adhere tightly to tissues but not to opposing tissues. This study investigated the antiadhesive and fixative characteristics of the PLLA nanosheet after placement of intraperitoneal onlay PPM (IPOM) overlaid with a PLLA nanosheet on intact peritoneum.
    Methods The PLLA nanosheet was fabricated by the spin-coating method and peeling technique with polyvinyl alcohol (PVA) as a supporting film. Two 1.5-cm-square pieces of mesh were implanted on each peritoneal side of the midline incision. The mesh was fixed to the peritoneum with a suture and then overlaid with a 4-cm-square piece of Seprafilm or nanosheet. To examine the fixative property, mesh was overlaid with Seprafilm or nanosheet without a fixed suture. After 4 weeks, mesh adhesion, inflammatory reaction, fixation, and dislocation of mesh were evaluated.
    Results Nanosheet-overlaid meshes were flexible and fit over the peritoneum. Adhesion was observed in 10% of the nanosheet-overlaid meshes and in 50% of the Seprafilm-overlaid meshes. The adhesion tenacity grade was significantly lower with the nanosheet-overlaid meshes (0.1 +/- A 0.1) than with the Seprafilm-overlaid meshes (1.0 +/- A 0.4) (p = 0.029), and the percentage of the adhesion area also was lower with the nanosheet-overlaid meshes (1.0 +/- A 1.0% vs 8.5 +/- A 3.2%; p = 0.037). The mean inflammatory cell counts were lower with the nanosheet-overlaid meshes (p = 0.0023). Regarding the fixative property, 37.5% of the nanosheet-overlaid meshes were fixated on the peritoneum, but no Seprafilm-overlaid mesh was fixated.
    Conclusions Overlaying of a PLLA nanosheet was effective for adhesion prophylaxis of intraperitoneal mesh. It also may have a possible beneficial effect on fixation of mesh.

    DOI

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    25
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  • Intravenous injection of Hb-vesicles (artificial oxygen carriers) after hemodilution with a series of plasma expanders (water-soluble biopolymers) in a rat repeated hemorrhage model.

    H. Sakai, N. Miyagawa, H. Horinouchi, S. Takeoka, M. Takaori, E. Tsuchida, K. Kobayashi

    Polymers Adv. Technol.   22   1216-1222  2011年08月  [査読有り]

    DOI

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    4
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  • Gas bioengineering using hemoglobin-vesicles for versatile clinical application.

    H. Sakai, S. Takeoka, K. Kobayashi

    Current Pharmaceutical Design   17   2352-2359  2011年07月

    DOI

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    4
    被引用数
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  • Fabrication, Properties, and Biomedical Applications of Nanosheets

    Toshinori Fujie, Yosuke Okamura, Shinji Takeoka

    Functional Polymer Films   2   907 - 931  2011年06月  [査読有り]

     概要を見る

    Nanosheets, ultrathin sheet-shaped materials, have several advantages in the biomedical field
    a large contact area in the biointerface, noncovalent adhesion, small amount ofmaterial required, and dual surfaces for heterofunctionalization. In terms of a drug-delivery vehicle, the sheet-shaped carriers perform unique dynamic functions over spherically shaped carriers. For surgical dressing, the sheet-shaped materials can densely overlap the tissue defect site without the need for chemical adhesive reagents. In this review, we propose a methodology for the preparation of freestanding, ultrathin nanosheets with a huge aspect ratio and heterosurfaces, fabricated through molecular assembly. In their practical biomedical applications, the micrometer-sized nanosheet was constructed by exploiting a micropatterned substrate with a precisely controlled size, applicable for injectable sheet-shaped drug carriers, whereas the giant nanosheets, with an aspect ratio of &gt
    106, can act as novel biomaterials for surgical dressing in the next generation of minimally invasive treatments. © 2011 Wiley-VCH Verlag GmbH &amp
    Co. KGaA.

    DOI

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    12
    被引用数
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  • Multiplex analysis of sphingolipids using amine-reactive tags (iTRAQ)

    Takuji Nabetani, Asami Makino, Francoise Hullin-Matsuda, Taka-aki Hirakawa, Shinji Takeoka, Nozomu Okino, Makoto Ito, Toshihide Kobayashi, Yoshio Hirabayashi

    JOURNAL OF LIPID RESEARCH   52 ( 6 ) 1294 - 1302  2011年06月

     概要を見る

    Ceramides play a crucial role in divergent signaling events, including differentiation, senescence, proliferation, and apoptosis. Ceramides are a minor lipid component in terms of content; thus, highly sensitive detection is required for accurate quantification. The recently developed isobaric tags for relative and absolute quantitation (iTRAQ) method enables a precise comparison of both protein and aminophospholipids. However, iTRAQ tagging had not been applied to the determination of sphingolipids. Here we report a method for the simultaneous measurement of multiple ceramide and monohexosylceramide samples using iTRAQ tags. Samples were hydrolyzed with sphingolipid ceramide N-deacylase (SCDase) to expose the free amino group of the sphingolipids, to which the N-hydroxysuccinimide group of iTRAQ reagent was conjugated. The reaction was performed in the presence of a cleavable detergent, 3-[3-(1,1-bisalkyloxyethyl)pyridine-1-yl]propane-1-sulfonate (PPS) to both improve the hydrolysis and ensure the accuracy of the mass spectrometry analysis performed after iTRAQ labeling. This method was successfully applied to the profiling of ceramides and monohexosylceramides in sphingomyelinase-treated Madin Darby canine kidney (MDCK) cells and apoptotic Jurkat cells.-Nabetani, T., A. Makino, F. Hullin-Matsuda, T. Hirakawa, S. Takeoka, N. Okino, M. Ito, T. Kobayashi, and Y. Hirabayashi. Multiplex analysis of sphingolipids using amine-reactive tags (iTRAQ). J. Lipid Res. 2011. 52: 1294-1302.

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  • Aqueous Colloidal Mesoporous Nanoparticles with Ethenylene-Bridged Silsesquioxane Frameworks

    Chihiro Urata, Hironori Yamada, Ryutaro Wakabayashi, Yuko Aoyama, Shota Hirosawa, Satoshi Arai, Shinji Takeoka, Yusuke Yamauchi, Kazuyuki Kuroda

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   133 ( 21 ) 8102 - 8105  2011年06月

     概要を見る

    Aqueous colloidal mesoporous nanoparticles with ethenylene-bridged silsesquioxane frameworks with a uniform diameter of similar to 20 nm were prepared from bis(triethoxysilyl)ethenylene in a basic aqueous solution containing cationic surfactants. The nanopartides, which had higher hydrolysis resistance under aqueous conditions, showed lower hemolytic activity toward bovine red blood cells than colloidal mesoporous silica nanoparticles.

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  • Free-Standing Poly(L-lactic acid) Nanofilms Loaded with Superparamagnetic Nanoparticles

    Silvia Taccola, Andrea Desii, Virginia Pensabene, Toshinori Fujie, Akihiro Saito, Shinji Takeoka, Paolo Dario, Arianna Menciassi, Virgilio Mattoli

    LANGMUIR   27 ( 9 ) 5589 - 5595  2011年05月

     概要を見る

    Freely suspended nanocomposite thin films based on soft polymers and functional nanostructures have been widely investigated for their potential application as active elements in microdevices. However, most studies are focused on the preparation of nanofilms composed of polyelectrolytes and charged colloidal particles. Here, a new technique for the preparation of poly(L-lactic acid) free-standing nanofilms embeddidng superparamagnetic iron oxide nanoparticles is presented. The fabrication process, based on a spin-coating deposition approach, is described, and the influence of each production parameter on the morphology and magnetic properties of the final structure is investigated. Superparamagnetic free-standing nanofilms were obtained, as evidenced by a magnetization hysteresis measurement performed with a superconducting quantum interference device (SQUID). Nanofilm surface morphology and thickness were evaluated by atomic force microscopy (AFM), and the nanoparticle dispersion inside the composites was investigated by transmission electron microscopy (TEM). These nanofilms, composed of a biodegradable polyester and remotely controllable by external magnetic fields, are promising candidates for many potential applications in the biomedical field.

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  • A Few Immobilized Thrombins Are Sufficient for Platelet Spreading

    Yosuke Okamura, Roman Schmidt, Ines Raschke, Maik Hintze, Shinji Takeoka, Alexander Egner, Thorsten Lang

    BIOPHYSICAL JOURNAL   100 ( 8 ) 1855 - 1863  2011年04月

     概要を見る

    Eukaryotic cells respond to signaling molecules with picomolar to nanomolar sensitivities. However, molar concentrations give no suggestion of the sufficient number of molecules per cell and are confusing when referring to physiological situations in which signaling molecules act in an immobilized state. Here, we studied platelet adhesion by thrombin, a key step in normal hemostasis and pathological arterial thrombosis. We generated a biofunctional nanosheet surface to mimic the in vivo solid-state interaction between platelets and thrombin at sites of injured tissues. We observed that &lt;10 molecules readily activate platelets with high specificity, resulting in platelet adhesion and spreading. This number is much lower than expected from previous experiments in solution, in which the sole activation of platelets required a &gt;1000-fold stoichiometric excess of thrombin. We conclude that immobilizing thrombin apposed to the membrane receptor allows platelets to respond with very high sensitivity. Moreover, we propose that irreversible cell activation may require several ligands to avoid activation by single, mislocalized signaling molecules.

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  • Decoration of fibrinogen γ-chain peptide on adenosine diphosphate-encapsulated liposomes enhances binding of the liposomes to activated platelets

    Koji Tokutomi, Toshiaki Tagawa, Maki Korenaga, Masatoshi Chiba, Tomohiro Asai, Naohide Watanabe, Shinji Takeoka, Makoto Handa, Yasuo Ikeda, Naoto Oku

    International Journal of Pharmaceutics   407 ( 1-2 ) 151 - 157  2011年04月

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  • Chirality Sensing by Nonchiral Porphines

    Jan Labuta, Shinsuke Ishihara, Atsuomi Shundo, Satoshi Arai, Shinji Takeoka, Katsuhiko Ariga, Jonathan P. Hill

    CHEMISTRY-A EUROPEAN JOURNAL   17 ( 13 ) 3558 - 3561  2011年03月

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  • Increased viscosity of hemoglobin-based oxygen carriers retards NO-binding when perfused through narrow gas-permeable tubes

    Hiromi Sakai, Naoto Okuda, Shinji Takeoka, Eishun Tsuchida

    MICROVASCULAR RESEARCH   81 ( 2 ) 169 - 176  2011年03月

     概要を見る

    Increased fluid viscosity of a solution of hemoglobin-based oxygen carriers (HBOCs) reduces vasoconstrictive effects because increased shear stress on the vascular wall enhances the production of vasorelaxation factors such as NO. Nevertheless, on a microcirculatory level, it remains unclear how viscosity affects the reaction of HBOCs and NO. In this study, different HBOCs were perfused through narrow gas-permeable tubes (25 mu m inner diameter at 1 mm/s centerline velocity; hemoglobin concentration [Hb] = 5 g/dL). The reaction was examined microscopically based on the Hb visible-light absorption spectrum. When immersed in a NO atmosphere, the NO-binding of deoxygenated Hb solution (viscosity, 1.1 cP at 1000 s(-1)) in the tube occurred about twice as rapidly as that of red blood cells (RBCs): 1.6 cP. Binding was reduced by PEGylation (PEG-Hb, 7.7 cP), by addition of a high molecular weight hydroxyethyl starch (HES) (2.8 cP), and by encapsulation to form Hb-vesicles (HbVs, 1.5 cP; particle size 279 nm). However, the reduction was not as great as that shown for RBCs. A mixture of HbVs and HES (6.2 cP) showed almost identical NO-binding to that of RBCs. Higher viscosity and particle size might reduce lateral diffusion when particles are flowing. The HbVs with HES showed the slowest NO-binding. Furthermore, Hb encapsulation and PEGylation, but not HES-addition, tended to retard CO-binding. Increased viscosity reportedly enhances production of endothelium NO. In addition, our results show that the increased viscosity also inhibits the reaction with NO. Each effect might mitigate vasoconstriction. (C) 2010 Elsevier Inc. All rights reserved.

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  • 高分子ナノシートの物性と医療展開

    齊藤晃広, 武岡真司

    未来材料   11 ( 3 ) 24 - 28  2011年03月

    CiNii

  • 分子集合科学による高分子超薄膜(ナノシート)の調製とナノ絆創膏としての医療展開

    武岡真司

    応用物理   80 ( 2 ) 133 - 136  2011年02月

  • Fluorescent "Turn-on" system utilizing a quencher-conjugated peptide for specific protein labeling of living cells

    Satoshi Arai, Su-In Yoon, Atsushi Murata, Masao Takabayashi, Xiaoyu Wu, Yixin Lu, Shinji Takeoka, Miwako Ozaki

    BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS   404 ( 1 ) 211 - 216  2011年01月

     概要を見る

    A specific protein fluorescent labeling method has been used as a tool for bio-imaging in living cells. We developed a novel system of switching "fluorescent turn on" by the recognition of a fluorescent probe to a hexahistidine-tagged (His-tag) protein. The tetramethyl rhodamine bearing three nitrilotriacetic acids, which was used as a fluorescent probe to target a His-tagged protein, formed a reversible complex with the quencher, (Dabcyl)-conjugated oligohistidines, in the homogeneous solution, causing fluorescence of the fluorophore to be quenched. The complex when applied to living cells (COS-7) expressing His-tagged proteins on the cell surface caused the quencher-conjugated oligohistidines to be dissociated from the complex by specific binding of the fluorescent probe to the tagged protein, resulting in the fluorescent emission. The complex that did not participate in the binding event remained in the quenched state to maintain a low level of background fluorescence. (C) 2010 Elsevier Inc. All rights reserved.

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  • Convenient method for surface modification by patching a freestanding anti-biofouling nanosheet

    Toshinori Fujie, Hiroki Haniuda, Shinji Takeoka

    JOURNAL OF MATERIALS CHEMISTRY   21 ( 25 ) 9112 - 9120  2011年

     概要を見る

    A convenient method for surface modification is crucially important for the preparation of a functional interface. The precise control of surface properties by chemical and physical approaches is expected to enhance the potential application of innovative nanomaterials. In this study, we propose a methodology for convenient surface modification using a freestanding anti-biofouling ultra-thin film (nanosheet) bearing poly(2-methacryloyloxyethyl phosphorylcholine: MPC) (i.e., pMPC-nanosheets). The physicochemical properties of the pMPC-nanosheet such as physiological stability, surface wettability and anti-biofouling were precisely controlled by means of thermal crosslinking of the nanosheet, the grafting amount of MPC and tuning the thickness of pMPC brushes. These approaches revealed physicochemical insight into the pMPC-nanosheet and its remarkable biological response. The pMPC-nanosheet was prepared via a spin-coating assisted layer-by-layer method in combination with atom transfer radical polymerization of MPC. The freestanding pMPC-nanosheet, comprising an 11 nm-thick pMPC brushed layer with a hydrophilic surface, was easily transferred by tweezers, cut by scissors, patterned by a needle and patched onto various interfaces with the aid of a water-soluble supporting film. The pMPC-nanosheets patched on cell culture substrates displayed anti-biofouling properties such as anti-coagulant activity against human whole blood as well as the potential to microscopically pattern murine fibroblast cells. The present study not only reveals physicochemical properties of the surface-functionalized nanosheet for biological application, but also constitutes an alternative approach to conventional lithographic techniques using photoresists and micro-patterned molds; thereby providing a new tool in the field of nanobiotechnology.

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  • Ultra-thin conductive free-standing PEDOT/PSS nanofilms

    Francesco Greco, Alessandra Zucca, Silvia Taccola, Arianna Menciassi, Toshinori Fujie, Hiroki Haniuda, Shinji Takeoka, Paolo Dario, Virgilio Mattoli

    SOFT MATTER   7 ( 22 ) 10642 - 10650  2011年

     概要を見る

    Free-standing conductive ultra-thin films based on poly(3,4-ethylenedioxythiophene)/poly (styrenesulfonate) (PEDOT/PSS) are realized. A fabrication process based on a modified Supporting Layer technique is proposed that provides for the easy production of conductive nanofilms having a very large surface area with typical thickness of tens of nanometres. The proposed free-standing nanofilms can be manipulated, folded and unfolded in water many times without suffering from cracks, disaggregation or from loss of conductive properties. After collecting them onto rigid or soft substrates, they retain their functionality. Structural and functional properties of the nanofilms are described by means of their thickness, topography, conductivity and Young's modulus. Strong dependences of these properties on residual water, post-deposition treatments and environmental moisture are clearly evidenced. Possible applications are foreseen in the field of sensing and actuation, as well as in the biomedical field, e. g. as smart substrates for cell culturing and stimulation.

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  • Release abilities of adenosine diphosphate from phospholipid vesicles with different membrane properties and their hemostatic effects as a platelet substitute

    Yosuke Okamura, Shunsuke Katsuno, Hidenori Suzuki, Hitomi Maruyama, Makoto Handa, Yasuo Ikeda, Shinji Takeoka

    JOURNAL OF CONTROLLED RELEASE   148 ( 3 ) 373 - 379  2010年12月

     概要を見る

    We have constructed phospholipid vesicles with hemostatic activity as a platelet substitute. The vesicles were conjugated with a dodecapeptide (HHLGGAKQAGDV, H12), which is a fibrinogen gamma-chain carboxy-terminal sequence (gamma 400-411). We have recently exploited these vesicles as a potential drug delivery system by encapsulation of adenosine 5'-diphosphate (ADP) (H12-(ADP)-vesicles).
    Here we explore the relationship between the ADP release from H12-(ADP)-vesicles with different membrane properties and their hemostatic effects. In total, we prepared five kinds of H12-(ADP)-vesicles with different lamellarities and membrane flexibilities. By radioisotope-labeling, we directly show that H12-(ADP)-vesicles were capable of augmenting platelet aggregation by releasing ADP in an aggregation-dependent manner. The amount of ADP released from the vesicles was dependent on their membrane properties. Specifically, the amount of ADP released increased with decreasing lamellarity and tended to increase with increasing membrane flexibility. Our in vivo results clearly demonstrated that H12-(ADP)-vesicles with the ability to release ADP exert considerable hemostatic action in terms of correcting prolonged bleeding time in a busulphan-induced thrombocytopenic rat model.
    We propose a recipe to control the hemostatic abilities of H12-(ADP)-vesicles by modulating ADP release based on membrane properties. We believe that this concept will be invaluable to the development of platelet substitutes and other drug carriers. (C) 2010 Elsevier B.V. All rights reserved.

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  • Construction of a 'turn-on' fluorescent probe system for His-tagged proteins

    Atsushi Murata, Satoshi Arai, Su-In Yoon, Masao Takabayashi, Miwako Ozaki, Shinji Takeoka

    BIOORGANIC & MEDICINAL CHEMISTRY LETTERS   20 ( 23 ) 6905 - 6908  2010年12月

     概要を見る

    Hexahistidine ((His)(6)) tags are used to purify genetically engineered proteins. Herein, we describe the construction of a 'turn-on' fluorescent probe system that consists of the fluorescence quencher, Dabcyl, conjugated to (His)(6), and fluorescent tetramethylrhodamine conjugated to nitrilotriacetic acid, which, in the presence of Ni2+, can bind (His)(6). The system is turned off when Dabcyl-(His)(6) is bound to the fluorescent nitrilotriacetic acid derivative. The binding strength of this system was assessed using electrospray ionization mass spectrometry, fluorescence correlation spectroscopy, and fluorescence intensity distribution analysis-polarization. Although there was no significant enhancement in fluorescence after addition of an equimolar amount of ubiquitin, the fluorescence increased from 14% to 40% of its initial intensity when an equimolar amount of (His)(6)-ubiquitin was added. Therefore, this system should be able to specifically recognize (His)(6)-proteins with good resolution and has the additional advantage that a washing step is not required to remove fluorescent probe, that is, not bound to the (His)(6)-protein. (C) 2010 Elsevier Ltd. All rights reserved.

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  • 高分子超薄膜(ナノシート)の医用材料としての展開

    藤枝 俊宣, 武岡 真司

    高分子   59 ( 12 ) 930 - 931  2010年12月

    CiNii

  • FLUORESCENT "TURN-ON" SYSTEM UTILIZING THE QUENCHER-CONJUGATED PEPTIDE TOWARD SPECIFIC PROTEIN LABELLING IN LIVE CELL

    S. Yoon, S. Arai, A. Murata, M. Takabayashi, X. Wu, Y. Lu, S. Takeoka, M. Ozaki

    JOURNAL OF NEUROCHEMISTRY   115   27 - 28  2010年10月

  • Adhesion and proliferation of skeletal muscle cells on single layer poly(lactic acid) ultra-thin films

    Leonardo Ricotti, Silvia Taccola, Virginia Pensabene, Virgilio Mattoli, Toshinori Fujie, Shinji Takeoka, Arianna Menciassi, Paolo Dario

    BIOMEDICAL MICRODEVICES   12 ( 5 ) 809 - 819  2010年10月

     概要を見る

    An increasing interest in bio-hybrid systems and cell-material interactions is evident in the last years. This leads towards the development of new nano-structured devices and the assessment of their biocompatibility. In the present study, the development of free-standing single layer poly(lactic acid) (PLA) ultra-thin films is described, together with the analysis of topography and roughness properties. The biocompatibility of the PLA films has been tested in vitro, by seeding C2C12 skeletal muscle cells, and thus assessing cells shape, density and viability after 24, 48 and 72 h. The results show that free-standing flexible PLA nanofilms represent a good matrix for C2C12 cells adhesion, spreading and proliferation. Early differentiation into myotubes is also allowed. The biocompatibility of the novel ultra-thin films as substrates for cell growth promotes their application in the fields of regenerative medicine, muscle tissue engineering, drug delivery, and-in general-in the field of bio-hybrid devices.

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    51
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  • Synthesis and self-assembling behavior of a porphyrin bearing multiple meso-conjugated barbiturates

    Satoshi Arai, Toshiya Okamura, Shinji Takeoka

    TETRAHEDRON LETTERS   51 ( 39 ) 5177 - 5180  2010年09月

     概要を見る

    An efficient procedure through deprotection of 2,4,6-trimethoxypyrimidine derivative afforded porphyrinato zinc bearing multi-barbiturates acting as multiple hydrogen bonding sites at the meso positions. Addition of excess amphiphilic triaminopyrimidine derivative, as a complementary motif to the barbiturate, in an aqueous solution of porphyrin conjugated with multiple barbiturates at the meso positions resulted in precipitation. The cast film from the chloroform solution of the precipitate indicated the formation of a well-defined porphyrin assembly. (c) 2010 Elsevier Ltd. All rights reserved.

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  • Dual therapeutic action of antibiotic-loaded nanosheets for the treatment of gastrointestinal tissue defects

    Toshinori Fujie, Akihiro Saito, Manabu Kinoshita, Hiromi Miyazaki, Shinya Ohtsubo, Daizoh Saitoh, Shinji Takeoka

    BIOMATERIALS   31 ( 24 ) 6269 - 6278  2010年08月

     概要を見る

    An ultra-thin polymer film (nanosheet) composed of polysaccharides (i.e., polysaccharide nanosheet) provides sufficient adhesiveness, flexibility and robustness to act as an effective wound dressing. We have recently demonstrated the sealing effect of a nanosheet on a murine cecal puncture. Nevertheless, a small percentage of bacteria penetrated the nanosheet because of its ultra-thin structure. Here, we have developed an antibiotic-loaded nanosheet to inhibit bacterial penetration and investigated its therapeutic efficacy using a model of a murine cecal puncture. Tetracycline (TC) was sandwiched between a poly(vinylacetate) (PVAc) layer and the polysaccharide nanosheet (named PVAc-TC-nanosheet). Under physiological conditions, TC was released from the nanosheet for 6 h. Microscopic observation between the interface of the PVAc-TC-nanosheet and bacteria demonstrated how its potent anti-microbial effect was achieved. In vivo studies show that overlapping therapy with the PVAc-TC-nanosheet (thickness: 177 nm) significantly increases mouse survival rate after cecal puncture as well as suppressing an increase in the intraperitoneal bacterial count and leukocyte count. (C) 2010 Elsevier Ltd. All rights reserved.

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  • Sealing effect of a polysaccharide nanosheet for murine cecal puncture

    Toshinori Fujie, Manabu Kinoshita, Satoshi Shono, Akihiro Saito, Yosuke Okamura, Daizoh Saitoh, Shinji Takeoka

    SURGERY   148 ( 1 ) 48 - 58  2010年07月

     概要を見る

    Background. Recent developments in nanobiotechnology have led us to develop a method of producing a free-standing polymer nanosheet composed of polysaccharides (ie, polysaccharide nanosheet) with a thickness of tens of nanometers. Owing to its enormous aspect ratio, the polysaccharide nanosheet is semi-absorbent and has a physical adhesive strength 7 5-fold greater than that of conventional films of &gt; 1 mu m thickness. Herein, we have investigated the therapeutic sealing effect of this polysaccharide nanosheet on murine cecal puncture as a wound dressing material.
    Methods. Murine cecum was punctured and then overlapped with the polysaccharide nanosheet Thereafter, we evaluated its sealing effect on bacterial peritonitis as well as the protection offered by the polysaccharide nanosheet against bacterial permeability using an in vitro transmembrane assay
    Results. The 39-nm-thick polysaccharide nanosheet overlapped tightly the perforated recant. No adhering agents were required because of the ability of the polysaccharide nanosheet to adhere to the tissue surface by physical adsorption (eg, van der Waals interaction) Sealing the perforated cecum with the polysaccharide nanosheet increased survival rate without postoperative adhesion by comparison with untreated mice (90 vs 30%, P &lt; .01) These data were supported by the improvement in peritonitis related to bacterial counts, white blood cell counts, and the serum tumor necrosis factor level. Moreover, using an. in vitro transmembrane assay, we showed that the polysaccharide nanosheet inhibited effectively bacterial penetration.
    Conclusion. We have demonstrated the potential clinical benefits of the nanosheet-type biomaterial that can be used for repairing a cecal colotomy without chemical bonding agents (Surgery 2010;148 48-58)

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  • 穿孔性腹膜炎に対するナノシートの応用

    藤枝俊宣, 木下学, 齋藤大蔵, 武岡真司

    Surgery Frontiea   17   37 - 43  2010年06月

  • Visualization of liposomes carrying fibrinogen gamma-chain dodecapeptide accumulated to sites of vascular injury using computed tomography

    Yosuke Okamura, Kaoruko Eto, Hitomi Maruyama, Makoto Handa, Yasuo Ikeda, Shinji Takeoka

    NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE   6 ( 2 ) 391 - 396  2010年04月

     概要を見る

    We have constructed liposomes with hemostatic activity as a platelet substitute using moderately thrombocytopenic rats. The liposomes were conjugated with the dodecapeptide (HHLGGAKQAGDV: H12), which is a fibrinogen gamma-chain C-terminal sequence (gamma 400-411). To visualize liposome accumulation at the site of vascular injury by in vivo computed tomography, a water-soluble contrast dye, N,N&apos;-bis[2-hydroxy-1-(hydroxylmethyl)ethyl]-5-[(2S)-2-hydroxylpropanoylamino]-2,4,6-triiodoisophthalamide (iopamidol), was encapsulated into the H12-conjugated liposomes. We achieved direct visualization of specific accumulation of the H12(iopamidol)liposomes at the jugular vein injured by ferric chloride and succeeded in semiquantitative analyses of the accumulated amount of H12-liposomes in the injured site. We therefore propose that H12-liposomes that are specifically recruited to, and exert their hemostatic activity at the site of vascular injury, have a significant potential as a carrier and/or as an ideal platelet substitute. Furthermore, the H12-(iopamidol)liposomes would also be clinically useful as diagnostic agents for pathological thrombus detection and as contrast dyes for hepatosplenography.
    From the Clinical Editor: The authors have constructed liposomes with hemostatic activity as a platelet substitute using moderately thrombocytopenic rats. They propose that H12-liposomes that are specifically recruited to, and exert their hemostatic activity at the site of vascular injury, have a significant potential as a carrier and/or as an ideal platelet substitute. Furthermore, the H12-(iopamidol)liposomes would also be clinically useful as diagnostic agents for thrombus detection and as contrast dyes for hepatosplenography. (C) 2010 Elsevier Inc. All rights reserved.

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  • Hemoglobin encapsulation in vesicles retards NO and CO binding and O-2 release when perfused through narrow gas-permeable tubes

    Hiromi Sakai, Naoto Okuda, Atsushi Sato, Tatsuya Yamaue, Shinji Takeoka, Eishun Tsuchida

    AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY   298 ( 3 ) H956 - H965  2010年03月

     概要を見る

    Sakai H, Okuda N, Sato A, Yamaue T, Takeoka S, Tsuchida E. Hemoglobin encapsulation in vesicles retards NO and CO binding and O-2 release when perfused through narrow gas-permeable tubes. Am J Physiol Heart Circ Physiol 298: H956-H965, 2010. First published December 31, 2009; doi:10.1152/ajpheart.00741.2009.-Intravenous administration of cell-free Hb induces vasoconstriction and circulatory disorders, presumably because of the intrinsic affinities to endogenous nitric oxide (NO) and carbon monoxide (CO) as vasorelaxation factors and because of the facilitated O-2 release that might induce autoregulatory vasoconstriction. We examined these gas reactions when Hb-containing solutions of four kinds were perfused through artificial narrow tubes at a practical Hb concentration (10 g/dl). Purified Hb solution, polymerized bovine Hb (Poly(B)Hb), encapsulated Hb [Hb-vesicles (HbV), 279 nm], and red blood cells (RBCs) were perfused through a gas-permeable narrow tube (25 mu m inner diameter) at 1 mm/s centerline velocity. The level of reactions was determined microscopically based on the visible-light absorption spectrum of Hb. When the tube was immersed in NO and CO atmospheres, both NO binding and CO binding of deoxygenated Hb (deoxy-Hb) and Poly(B)Hb in the tube was faster than those of HbV and RBCs, and HbV and RBCs showed almost identical binding rates. When the tube was immersed in a N-2 atmosphere, oxygenated Hb and Poly(B)Hb showed much faster O-2 release than did HbV and RBCs. Poly(B)Hb showed a faster reaction than Hb because of the lower O-2 affinity of Poly(B)Hb than Hb. The diffusion process of the particles was simulated using Navier-Stokes and Maxwell-Stefan equations. Results clarified that small Hb (6 nm) diffuses laterally and mixes rapidly. However, the large-dimension HbV shows no such rapid diffusion. The purely physicochemical differences in diffusivity of the particles and the resulting reactivity with gas molecules are one factor inducing biological vasoconstriction of Hb-based oxygen carriers.

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  • Evaluation of pH-responsive liposomes containing amino acid-based zwitterionic lipids for improving intracellular drug delivery in vitro and in vivo

    Yosuke Obata, Shoji Tajima, Shinji Takeoka

    JOURNAL OF CONTROLLED RELEASE   142 ( 2 ) 267 - 276  2010年03月

     概要を見る

    We developed pH-responsive liposomes containing synthetic glutamic acid-based zwitterionic lipids and evaluated their properties both in vitro and in vivo with the aim of constructing an efficient liposome-based systemic drug delivery system. The glutamic acid-based lipids; 1,5-dihexadecyl N-glutamyl-L-glutamate (L1) and 1,5-dihexadecyl N,N-diglutamyl-lysyl-L-glutamate (L2) were synthesized as a pH-responsive component of liposomes that respond to endosomal pH. The zeta potential of liposomes containing L1 or L2 was positive when the solution pH was below 4.6 or 5.6, respectively, but negative at higher pH values. The pH-responsive liposomes showed improved fusogenic potential to an endosome-mimicking anionic membrane at acidic pH, where the zeta potential of the liposomes was positive. We then prepared doxorubicin (DOX)-encapsulating liposomes containing L1 or 12, and clarified by confocal microscopic studies that the contents were rapidly transferred into both the cytoplasm and nucleus. Release of DOX from the endosomes mediated by the pH-responsive liposomes dramatically inhibited cancer cell growth. The L2-liposomes were slightly more effective than L1-liposomes as a drug delivery system. Intravenously injected L2-liposomes displayed blood persistence comparable to that of conventional phospholipid (PC)-based liposomes. Indeed, the antitumor efficacy of L2-liposomes was higher than that of PC-based liposomes against a xenograft breast cancer tumor in vivo. Thus, the high performance of L2-liposomes results from both efficient intracellular drug delivery and comparable blood persistence in comparison with the conventional PC-based liposomes in vitro and in vivo. (C) 2009 Elsevier B.V. All rights reserved.

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  • Evaluation of cationic liposomes composed of an amino acid-based lipid for neuronal transfection

    Yosuke Obata, Gianni Ciofani, Vittoria Raffa, Alfred Cuschieri, Arianna Menciassi, Paolo Dario, Shinji Takeoka

    NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE   6 ( 1 ) 70 - 77  2010年02月

     概要を見る

    We investigated the ability of cationic liposomes composed of 1,5-dihexadecyl N-arginyl-L-glutamate (Arg-Glu2C(16)) to carry nucleic acids into neuronal cells. Such liposomes have been shown to have a remarkable capacity for transfecting immortalized cell lines. Lipoplexes between the Arg-Glu2C(16) liposomes and plasmid DNA encoding green fluorescent protein (GFP) were analyzed in terms of lipoplex formation, intracellular DNA trafficking, transfection efficiency, and cytotoxicity in neuronal SH-SY5Y cells. A maximum number of cells expressing GFP was obtained with lipoplexes at a lipid-to-DNA ratio of 15. With these lipoplexes, 16% of the cells were GFP- positive, which was approximately fourfold higher than the level obtained with a commercially available transfection reagent, Lipofectamine 2000. Furthermore, as a result of the low cytotoxicity of the Arg-Glu2C(16) lipoplexes, the proportion of GFP- positive cells could be increased to 25% by increasing the concentration of lipoplexes that was applied to the cells. We have demonstrated that Arg-Glu2C(16), as a model cationic amino acid-based lipid, has a high capability as a gene carrier, even for neuronal transfection.
    From the Clinical Editor: In this study, specific cationic liposomes were characterized as nucleic acid transfection agents for neuronal cells. A fourfold higher transfection rate with low cytotoxicity was reported compared to Lipofectamine 2000, a commercial reagent. The authors conclude that the studied cationic liposomes have a high capability as a gene carrier for neuronal transfection. This may become clinically significant in future gene therapy efforts of neuronal diseases. (C) 2010 Elsevier Inc. All rights reserved.

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  • Drift and fluctuating motion of artificial platelet during adhesion process near the wall

    H. Tobimatsu, A. Paragon, Y. Okamura, S. Takeoka, R. Sudo, K. Tanishita

    IFMBE Proceedings   31   1075 - 1078  2010年  [査読有り]

     概要を見る

    To obtain long trajectories including lateral motion, we built a travelling stage of microscope for tracking particles moving through flow channel and estimated the lateral motion which contributes to NWE and adhesion. We employed recombinant Glycoprotein Ib alpha conjugated latex beads (rGPIbalpha-LB) as platelet substitute. These particles were observed at wall shear rate (WSR) of 200, 500, and 1000 /s with hematocrit of 0 and 40% of washed red blood cells in rectangular flow channel which had vWf surface. We tracked the particle as Lagrangian method and separated the trajectory of particle with drift and fluctuating motion, and investigated quantitatively the motion which contributes to NWE and adhesion to the wall surface. Trajectories of rGPIbalpha-LB were tracked from obtained movies. Then lateral gradient which reflects a drift motion of the particle toward the wall and dispersion coefficient which reflects a fluctuating motion of the particle were calculated. The rGPIbalpha-LB moved only along axial direction with 0% hematocrit. As hematocrit increases, rGPIbalpha-LB moved toward near the wall (about 0.9R) and the position was similar to that of NWE in previous studies. The dispersion coefficient increased near the wall and as WSR and hematocrit increased. In the near wall region, adhered particles showed significantly a tendency toward the wall and high fluctuating motion compared with non-contact particles. We concluded the particle which has drift motion toward the wall with high fluctuating motion induced by the presence of RBC and high shear contributes to interact to the wall surface and adhesion from NWE region. © 2010 International Federation for Medical and Biological Engineering.

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  • ~体内組織に『癒着しない』~ナノシートからなる手術用フィルムの開発

    藤枝 俊宣, 松谷 哲行, 木下 学, 武岡 真司

    MATERIAL STAGE   10 ( 4 ) 4 - 6  2010年  [招待有り]

    CiNii

  • 医療応用に向けた高分子超薄膜の新展開

    藤枝俊宣, 齋藤晃広, 武岡 真司

    表面   48 ( 7 ) 211 - 219  2010年  [査読有り]  [招待有り]

    CiNii

  • Basic consideration on tissue adhesion and sealing of ultra-thin nanobiomaterial in visceral pleural defect repair

    Matsutani, N, Fujie, T, Ozeki, Y, Takeoka, S

    JACSURG(日本呼吸器外科学会雑誌),   1   2 - 7  2010年

  • A nano-fibrous assembly of collagen-hyaluronic acid for controlling cell-adhesive properties

    Toshinori Fujie, Sho Furutate, Daisuke Niwa, Shinji Takeoka

    SOFT MATTER   6 ( 19 ) 4672 - 4676  2010年

     概要を見る

    We report an artificially fabricated extracellular matrix (ECM)-like nanostructure, which utilizes self-assembly of collagen and hyaluronic acid in a quasi two-dimensional space of tens-of-nm thickness, displaying different cellular adhesive characteristics depending on the structural properties between the fibril and non-fibril elements. This nano-fibrous assembly will facilitate a mechanobiological approach for the development of tissue-engineering scaffolds.

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  • Free-Standing Biodegradable Poly(lactic acid) Nanosheet for Sealing Operations in Surgery

    Yosuke Okamura, Koki Kabata, Manabu Kinoshita, Daizoh Saitoh, Shinji Takeoka

    ADVANCED MATERIALS   21 ( 43 ) 4388 - +  2009年11月

     概要を見る

    A free-standing biodegradable nanosheet composed of poly(L-lactic acid) (PLLA) was shown to have excellent sealing efficacy for a gastric incision as a novel wound dressing material that did not require adhesive agents, and the PLLA nanosheet-induced wound repair showed neither scars nor tissue adhesion. This material may, therefore, be an ideal alternative to conventional tissue repairing procedures using suture/ligation in surgery.

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    143
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  • Free-Standing Biodegradable Poly(lactic acid) Nanosheet for Sealing Operations in Surgery

    Yosuke Okamura, Koki Kabata, Manabu Kinoshita, Daizoh Saitoh, Shinji Takeoka

    ADVANCED MATERIALS   21 ( 43 ) 4388 - +  2009年11月

     概要を見る

    A free-standing biodegradable nanosheet composed of poly(L-lactic acid) (PLLA) was shown to have excellent sealing efficacy for a gastric incision as a novel wound dressing material that did not require adhesive agents, and the PLLA nanosheet-induced wound repair showed neither scars nor tissue adhesion. This material may, therefore, be an ideal alternative to conventional tissue repairing procedures using suture/ligation in surgery.

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    143
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  • Novel Platelet Substitutes: Disk-Shaped Biodegradable Nanosheets and their Enhanced Effects on Platelet Aggregation

    Yosuke Okamura, Yoshihito Fukui, Koki Kabata, Hidenori Suzuki, Makoto Handa, Yasuo Ikeda, Shinji Takeoka

    BIOCONJUGATE CHEMISTRY   20 ( 10 ) 1958 - 1965  2009年10月

     概要を見る

    We have studied biocompatible spherical carriers carrying a dodecapeptide, HHLGGAKQAGDV (H12), on their surface as platelet substitutes. This peptide is a fibrinogen gamma-chain carboxy-terminal sequence (gamma 400-411) and specifically recognizes the active form of glycoprotein IIb/IIIa on activated platelets. Our purpose is to assess the possibility of making a novel platelet substitute consisting of disk-shaped nanosheets having a large contact area for the targeting site, rather than conventional small contact area spherical carriers. ne H12 peptide was conjugated to the surface of the free-standing nanosheets made of biodegradable poly(D,L-lactide-co-glycolide) (PLGA). These H12-PLGA nanosheets were fabricated onto 3 mu m disk-shaped patterned hydrophobic octadecyl regions on a SiO(2) substrate. By way of comparison, spherical H12-PLGA microparticles with the same surface area and conjugation number of H12 were also prepared. The resulting H12-PLGA nanosheets specifically interacted with the activated platelets adhered on the collagen surface at twice the rate of the H12-PLGA microparticles under flow conditions, and showed platelet thrombus formation in a two-dimensional spreading manner. Thus, H12-PLGA nanosheets might be a suitable candidate novel platelet alternative substitute for infused human platelet concentrates for the treatment of bleeding in patients with severe thrombocytopenia.

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    35
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  • Novel Platelet Substitutes: Disk-Shaped Biodegradable Nanosheets and their Enhanced Effects on Platelet Aggregation

    Yosuke Okamura, Yoshihito Fukui, Koki Kabata, Hidenori Suzuki, Makoto Handa, Yasuo Ikeda, Shinji Takeoka

    BIOCONJUGATE CHEMISTRY   20 ( 10 ) 1958 - 1965  2009年10月

     概要を見る

    We have studied biocompatible spherical carriers carrying a dodecapeptide, HHLGGAKQAGDV (H12), on their surface as platelet substitutes. This peptide is a fibrinogen gamma-chain carboxy-terminal sequence (gamma 400-411) and specifically recognizes the active form of glycoprotein IIb/IIIa on activated platelets. Our purpose is to assess the possibility of making a novel platelet substitute consisting of disk-shaped nanosheets having a large contact area for the targeting site, rather than conventional small contact area spherical carriers. ne H12 peptide was conjugated to the surface of the free-standing nanosheets made of biodegradable poly(D,L-lactide-co-glycolide) (PLGA). These H12-PLGA nanosheets were fabricated onto 3 mu m disk-shaped patterned hydrophobic octadecyl regions on a SiO(2) substrate. By way of comparison, spherical H12-PLGA microparticles with the same surface area and conjugation number of H12 were also prepared. The resulting H12-PLGA nanosheets specifically interacted with the activated platelets adhered on the collagen surface at twice the rate of the H12-PLGA microparticles under flow conditions, and showed platelet thrombus formation in a two-dimensional spreading manner. Thus, H12-PLGA nanosheets might be a suitable candidate novel platelet alternative substitute for infused human platelet concentrates for the treatment of bleeding in patients with severe thrombocytopenia.

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    35
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  • Adhesive, Flexible, and Robust Polysaccharide Nanosheets Integrated for Tissue-Defect Repair

    Toshinori Fujie, Noriyuki Matsutani, Manabu Kinoshita, Yosuke Okamura, Akihiro Saito, Shinji Takeoka

    ADVANCED FUNCTIONAL MATERIALS   19 ( 16 ) 2560 - 2568  2009年08月

     概要を見る

    Recent developments in nanotechnology have led to a method for producing free-standing polymer nanosheets as a macromolecular organization. Compared with bulk films, the large aspect ratio of such nanosheets leads to unique physical properties, such as transparency, noncovalent adhesion, and high flexibility. Here, a biomedical application of polymer nanosheets consisting of biocompatible and biodegradable polysaccharides is reported. Micro-scratch and bulge tests indicate that the nanosheets with a thickness of tens of nanometers have sufficient physical adhesiveness and mechanical strength for clinical use. A nanosheet of 75 nm thickness, a critical load of 9.1 x 10(4) N m(-1), and an elastic modulus of 9.6 GPa is used for the minimally invasive repair of a visceral pleural defect in beagle dogs without any pleural adhesion caused by wound repair. For the first time, clinical benefits of sheet-type nano-biomaterials based on molecular organization are demonstrated, suggesting that novel therapeutic tools for overlapping tissue wounds will be possible without the need for conventional surgical interventions.

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    161
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  • Mechanism of Flocculate Formation of Highly Concentrated Phospholipid Vesicles Suspended in a Series of Water-Soluble Biopolymers

    Hiromi Sakai, Atsushi Sato, Shinji Takeoka, Eishun Tsuchida

    BIOMACROMOLECULES   10 ( 8 ) 2344 - 2350  2009年08月

     概要を見る

    Polyethylene glycol-modified vesicles (liposomes) encapsulating hemoglobin (HbV) are artificial oxygen carriers that have been developed as a transfusion alternative. The HbV suspension in an albumin solution is nearly Newtonian; other biopolymers, hydroxyethyl starch (HES), dextran (DEX), and modified fluid gelatin, induce flocculation of HbVs through depletion interaction and render the suspensions as non-Newtonian. The flocculation level increased with hydrodynamic radius (R(h)) or radius of gyration (R(g)) of series of HES or DEX with different molecular weights at a constant polymer concentration (4 wt %). However, the flocculation level differed markedly among the polymers. A crowding index (C(i)) representing the crowding level of a polymer solution is defined as (excluded volume of one polymer) x (molar concentration) x Avogadro&apos;s number, using R(h) or R(g). All polymers&apos; flocculation level increases when C(i) approaches 1: when the theoretical total excluded Volumes approach the entire solution Volume, the excluded HbV particles are forced to flocculate.

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  • Peculiar flow patterns of RBCs suspended in viscous fluids and perfused through a narrow tube (25 μm)

    Sakai, H, Sato, A, Okuda, N, Takeoka, S, Maeda, N, Tsuchida, E

    Amer. J. Phys-Heart Circ. Phys.   297 ( 2 ) H583 - H589  2009年08月

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  • Hydrodynamic Transformation of a Freestanding Polymer Nanosheet Induced by a Thermoresponsive Surface

    Toshinori Fujie, Jin Young Park, Atsushi Murata, Nicel C. Estillore, Maria Celeste R. Tria, Shinji Takeoka, Rigoberto C. Advincula

    ACS APPLIED MATERIALS & INTERFACES   1 ( 7 ) 1404 - 1413  2009年07月

     概要を見る

    Freestanding quasi-two-dimensional ultrathin films (e,g., 41 nm thick polymer nanosheets) were produced. on which stimuli-responsive 47 nm chick polymer brushes were constructed by atom transfer radical polymerization (ATRP) of poly(N-isopropylacrylamide). The resulting surfaces of the multilayered polysaccharide ultrathin films were evaluated by ellipsometry, IR imaging, In situ variable-temperature atomic force microscopy (AFM), and contact angle measurements. The morphological transformation of the freestanding polymer nanosheet bearing thermoresponsive polymer brushes was observed macroscopically through reversible structural color changes at the air-water interface. The dynamic shape change of the nanosheetwas also monitored with the addition of a surfactant such as sodium n-dodecylsulfate to reduce the hydrophobicity of the surface, It was then demonstrated chat the highly flexible freestanding polymer nanosheet is capable of acting as a unique platform for inducing stimuli-responsive I behavior in nanomaterials.

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  • Effect of hemoglobin vesicles, cellular-type artificial oxygen carriers, on the ex vivo expansion of human hematopoietic stem/progenitor cells using a coculture system with human stromal cells.

    M. Yamaguchi, M. Fujihara, S. Wakamoto, H. Sakai, S. Takeoka, E. Tsuchida, H. Hamada, H. Azuma, H. Ikeda

    ASAIO J.   55   200-205  2009年05月  [査読有り]

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  • Plasmid DNA-encapsulating liposomes: Effect of a spacer between the cationic head group and hydrophobic moieties of the lipids on gene expression efficiency

    Yosuke Obata, Shunsuke Saito, Naoya Takeda, Shinji Takeoka

    BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES   1788 ( 5 ) 1148 - 1158  2009年05月

     概要を見る

    We have synthesized a series of cationic amino acid-based lipids having a spacer between the cationic head group and hydrophobic moieties and examined the influence of the spacer on a liposome gene delivery system. As a comparable spacer, a hydrophobic spacer with a hydrocarbon chain composed of 0, 3, 5, 7, or 11 carbons, and a hydrophilic spacer with an oxyethylene chain (10 carbon and 3 oxygen molecules) were investigated. Plasmid DNA (pDNA)-encapsulating liposomes were prepared by mixing an ethanol solution of the lipids with an aqueous solution of pDNA. The zeta potentials and cellular uptake efficiency of the cationic liposomes containing each synthetic lipid were almost equivalent. However, the cationic lipids with the hydrophobic spacer were subject to fuse with biomembrane-mimicking liposomes. 1,5-Dihexadecyl-N-lysyl-N-heptyl-L-glutamate, having a seven carbon atom spacer, exhibited the highest fusogenic potential among the synthetic lipids. Increased fusion potential correlated with enhanced gene expression efficiency. By contrast, an oxyethylene chain spacer showed low gene expression efficiency. We conclude that a hydrophobic spacer between the cationic head group and hydrophobic moieties is a key component for improving pDNA delivery. (C) 2009 Elsevier B.V. All rights reserved.

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  • Biocompatibility Study of Hemoglobin Vesicles, Cellular-Type Artificial Oxygen Carriers, with Human Umbilical Cord Hematopoietic Stem/Progenitor Cells Using an In Vitro Expansion System

    Miki Yamaguchi, Mitsuhiro Fujihara, Shinobu Wakamoto, Hiromi Sakai, Shinji Takeoka, Eishun Tsuchida, Hirofumi Hamada, Hiroshi Azuma, Hisami Ikeda

    ASAIO JOURNAL   55 ( 3 ) 200 - 205  2009年05月

     概要を見る

    Hemoglobin vesicles (HbVs), liposomal oxygen carriers containing human hemoglobin, are candidates for development of a clinically useful transfusion alternative. Our previous in vivo animal studies of massive HbV dosages demonstrated the lack of any suppressive effect on hematopoiesis. Before starting clinical trials, we aimed to examine the details of the biocompatibility of HbVs with human hematopoietic stem/progenitor cells. We investigated the effect of HbVs at a concentration of up to 3 vol/vol (%) on expansion of human umbilical cord (CB) hernatopoietic stem/progenitor cells, using a coculture system of human TERT-transfected bone marrow stromal cells and CD34(+) cells in vitro. The exposure of CB CD34(+) cells to HbVs up to 14 days suppressed the expansion of total cells and the CD34(+) cells themselves, whereas the empty liposomes, that did not contain Hb, had modestly inhibitory effects on the expansion of these cells. As a result, the number of colonies obtained from the expanded CD34(+) cells was inhibited by the exposure to HbVs. In contrast, exposure to HbVs for 3 days had no effect on the expansion of CD34(+) cells and only slightly decreased the number of total cells. Our in vitro experimental condition does not fully recreate the physiological condition, and the effect of the direct contact of HbV would be magnified because of the absence of shielding by the vasculature and the lack of the reticuloendothelial system and blood stream. However, the present data raise some concern regarding hematopoiesis, and one has to pay attention to this in future human clinical trials. ASAIO Journal 2009; 55:200-205.

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  • Fabrication of free-standing albumin-nanosheets having heterosurfaces

    Yosuke Okamura, Takahiro Goto, Daisuke Niwa, Yoshihito Fukui, Masanobu Otsuka, Norikazu Motohashi, Tetsuya Osaka, Shinji Takeoka

    JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A   89A ( 1 ) 233 - 241  2009年04月

     概要を見る

    Sheet-shaped carriers, having both obverse and reverse surfaces and thus a large contact area for targeting a site, have several advantages over spherical-shaped carriers, which have an extremely small contact area for targeting sites. Here, we proposed a novel method to prepare a free-standing ultrathin and biocompatible nanosheet having heterosurfaces, by a combination of four processes: (1) specific adsorption of recombinant human serum albumin (rHSA) molecules onto a patterned octadecyltrimethoxysilane self-assembled monolayer region (ODS-SAM), (2) preparation of nanosheets of rHSA molecules bearing thiol groups (SH-rHSA) via two-dimensionally disulfide crosslinking, (3) surface modification of the resulting nanosheet, and. (4) preparation of the free-standing nanosheet by detachment from the ODS-SAM. The SH-rHSA molecules at pH 5.0 and a concentration of 1 mu g/ml, were specifically adsorbed on the patterned ODS-SAM regions by hydrophobic interaction, and were two-dimensionally crosslinked in the presence of copper ion as an oxidant. The rHSA-nanosheets were then simply detached from the ODS-SAM by treatment with surfactant. We succeeded in the preparation of rectangular (10 mu m X 30 mu m) and ultrathin (4.5 +/- 1.0 nm) rHSA-nanosheets on a patterned ODS-SAM, and could also obtain free-standing rHSA-nanosheets having heterosurfaces by Surface modification with fluorescent latex beads. Thus, the rHSA-nanosheets having heterosurfaces could be regarded as a new biomaterial for drug carriers, hemostatic reagents, wound dressing for burn injury, and so forth. (c) 2008 Wiley Periodicals, Inc. J Biomed Mater Res 89A: 233-241, 2009

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    6
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  • Development of fibrinogen gamma-chain peptide-coated, adenosine diphosphate-encapsulated liposomes as a synthetic platelet substitute

    Y. Okamura, S. Takeoka, K. Eto, I. Maekawa, T. Fujie, H. Maruyama, Y. Ikeda, M. Handa

    JOURNAL OF THROMBOSIS AND HAEMOSTASIS   7 ( 3 ) 470 - 477  2009年03月

     概要を見る

    Background: The dodecapeptide HHLGGAKQAGDV (H12), corresponding to the fibrinogen gamma-chain carboxy-terminal sequence (gamma 400-411), is a specific binding site of the ligand for platelet GPIIb/IIIa complex. We have evaluated H12-coated nanoparticles (polymerized albumin or liposome) as platelet function-supporting synthetic products. Objectives: To strengthen the hemostatic ability of H12-coated particles as a platelet substitute, we exploited installation of a drug delivery function by encapsulating adenosine diphosphate (ADP) into liposomes [H12-(ADP)-liposomes]. Methods and results: Via selective interaction with activated platelets through GPIIb/IIIa, H12-(ADP)-liposomes were capable of augmenting agonist-induced platelet aggregation by releasing ADP in an aggregation-dependent manner. When intravenously injected into rats, liposomes were readily targeted to sites of vascular injury as analyzed on computed tomography. In fact, comparable to fresh platelets, liposomes exhibited considerable hemostatic ability for correcting prolonged bleeding time in a busulphan-induced thrombocytopenic rabbit model. In addition, the liposomes showed no activating or aggregating effects on circulating platelets in normal rabbits. Conclusion: H12-(ADP)-liposome may thus offer a promising platelet substitute, being made with only synthetic materials and exerting hemostatic functions in vivo via reinforcement of primary thrombus formation by residual platelets in thrombocytopenia at sites of vascular injury, but not in circulation.

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    59
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  • Influence of hemoglobin vesicles, cellular-type artificial oxygen carriers, on human umbilical cord blood hematopoietic progenitor cells in vitro.

    M. Yamaguchi, M. Fujihara, S. Wakamoto, H. Sakai, S. Takeoka, E. Tsuchida, H. Azuma, H. Ikeda

    J. Biomed. Materials Res. A.   88A   34-42  2009年02月  [査読有り]

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  • Boron Nitride Nanotubes: A Novel Vector for Targeted Magnetic Drug Delivery

    Gianni Ciofani, Vittoria Raffa, Jun Yu, Ying Chen, Yosuke Obata, Shinji Takeoka, Arianna Menciassi, Alfred Cuschieri

    CURRENT NANOSCIENCE   5 ( 1 ) 33 - 38  2009年02月

     概要を見る

    Whereas several biomedical applications of carbon nanotubes have been proposed, the use of boron nitride nanotubes (BNNTs) in this field has been largely unexplored despite their unique and potentially useful properties. Our group has recently initiated an experimental program aimed at the exploration of the interactions between BNNTs and living cells. In the present paper, we report on the magnetic properties of BNNTs containing Fe catalysts which confirm the feasibility for their use as nanovectors for targeted drug delivery. The magnetisation curves of BNNTs characterised by the present study are typical of superparamagnetic materials with important parameters, including magnetic permeability and magnetic momentum, derived by employing Langevin theory. In-vitro tests have demonstrated the feasibility for influencing the uptake of BNNTs by living cells by exposure to an external magnetic source. A finite element method analysis devised to predict this effect produced predictive data with close agreement with the experimental observations.

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    91
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  • Realization, characterization and functionalization of lipidic wrapped carbon nanotubes

    Gianni Ciofani, Yosuke Obata, Izumi Sato, Yosuke Okamura, Vittoria Raffa, Arianna Menciassi, Paolo Dario, Naoya Takeda, Shinji Takeoka

    JOURNAL OF NANOPARTICLE RESEARCH   11 ( 2 ) 477 - 484  2009年02月

     概要を見る

    Mass-produced carbon nanotubes (CNTs) are strongly aggregated and highly hydrophobic, and processes to make them water soluble are required for biological applications. Both covalent and non-covalent strategies are pursued for obtaining stable, highly concentrated CNT aqueous dispersions. Covalent functionalization has the great disadvantage of producing an irreversible chemical modification of nanotubes, thus alterating their mechanical, chemical and electric properties. On the other hand, non-covalent functionalization is often obtained by employing surfactants that sensibly affect cell viability. Moreover, derivatization with biological moieties is often impossible through non-covalent CNT dispersion. This paper proposes a non-covalent dispersion of multi-wall CNT based on a lipidic mixture that can guarantee high concentration and high stability as well as high cytocompatibility. Moreover, CNTs wrapped with a lipid membrane are realized to demonstrate that the proposed CNTs can be functionalised with a dodecapeptide that specifically recognizes activated platelets without chemical modification of the nanotube itself.

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    12
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  • Selective surface modification of free-standing polysaccharide nanosheet with micro/nano-particles identified by structural color changes

    Toshinori Fujie, Yosuke Okamura, Shinji Takeoka

    COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS   334 ( 1-3 ) 28 - 33  2009年02月

     概要を見る

    The chemical and physical modification of a material surface is important for practical applications. In this study, we utilized the bilateral nature of a free-standing polysaccharide nanosheet as a platform for surface modification, selectively modifying the upper and lower surfaces with different sizes of latex beads. By means of a water-soluble sacrificial layer, we adsorbed latex beads with the diameter of 200 rim onto the obverse surface of the polysaccharide nanosheet as well as latex beads with that of 2 mu m onto the reverse side. The optical characteristics of the nanosheet were analyzed on the basis of &apos;thin film interference theory&apos; by making stepwise increments in thickness through sequentially overlaying free-standing 30nm polysaccharide nanosheets onto a SiO(2) substrate. The surface of the polysaccharide nanosheet was quite flat and smooth. Having confirmed by optical and scanning electron microscopy that we had achieved selective surface modification of the polysaccharide nanosheet with micro/nano-latex beads, we noted a unique optical property when the nanosheet was adsorbed on the SiO(2) substrate. The localization of the beads on the nanosheet surface produced structural colors in the films due to an optical interference. This selective surface modification technique will be utilized to create &apos;smart&apos; nanocomposites possessing different surface functions. (C) 2008 Elsevier B.V. All rights reserved.

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    23
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  • FLUID RESUSCITATION WITH ARTIFICIAL OXYGEN CARRIERS IN HEMORRHAGED RATS: PROFILES OF HEMOGLOBIN-VESICLE DEGRADATION AND HEMATOPOIESIS FOR 14 DAYS

    Hiromi Sakai, Yasushi Seishi, Yosuke Obata, Shinji Takeoka, Hirohisa Horinouichi, Eishun Tsuchida, Koichi Kobayashi

    SHOCK   31 ( 2 ) 192 - 200  2009年02月

     概要を見る

    Polyethylene glycol (PEG)-modified hemoglobin (Hb) vesicles (HbVs) are artificial oxygen carriers encapsulating a concentrated Hb solution in phospholipid vesicles. In our previous studies, HbV showed a sufficient resuscitative effect comparable to that of red blood cells in hemorrhagic shock animal models during several hours' observation. However, the profiles of the recovery, including hematopoiesis and elimination of HbV, remain unknown. This study conducted 14-day observations of Wistar rats after hemorrhagic shock and fluid resuscitation with HbV suspended in recombinant human serum albumin. Shock was induced by 50% blood withdrawal from a femoral artery. The rats showed hypotension, metabolic acidosis, and hyperventilation. After 15 min, they received HbV or shed autologous blood through a femoral vein. Both groups showed rapid recovery of hemodynamic and blood gas parameters. No meaningful difference was found between groups. After decannulation and awakening, the rats were housed in cages. The reduced hematocrit of the HbV group returned to the original level in 7 days. Plasma enzyme levels were slightly higher in both groups at 1 day because of systemic reperfusion injury. Splenomegaly was considerable in the HbV group because of the HbV accumulation and extramedullar hematopoiesis, but it subsided within 14 days. Along with the HbV elimination in the spleen and liver, immunohistochemistry with anti-PEG antibody revealed that PEG-conjugated lipid had disappeared within 14 days. In conclusion, HbV showed a sufficient resuscitative effect comparable to that of red blood cell transfusion. Phagocytized HbV disappeared within 14 days. Elevated hematopoiesis contributed to complete hematocrit recovery within 7 days.

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  • Biomedical application of polysaccharide nanosheet for tissue-defect repair

    Fujie, Toshinori, Matsutani, Noriyuki, Kinoshtia, Manabu, Okamura, Yosuke, Saito, Akihiro, Takeoka, Shinji

    Polym. Prepr. (Am. Chem. Soc., Div. Polym. Chem.)   50 ( 2 ) 432 - 433  2009年  [査読有り]

  • ナノテクノロジーにより作成した超極薄膜ナノシートを用いた穿孔性腹膜炎時の穿孔部閉鎖治療

    木下 学, 小野 聡, 藤枝 俊宣, 平木 修一, 辻本 広紀, 木村 曉史, 下野 浩貴, 岡村 陽介, 宮崎 裕美, 庄野 聡, 武岡 真司, 齋藤 大蔵, 関 修司

    日本腹部救急医学会雑誌   29 ( 6 ) 807 - 808  2009年  [招待有り]

    CiNii

  • 世界一薄い絆創膏を開発

    武岡 真司, 藤枝 俊宣

    化学   59 ( 11 ) 825 - 831  2009年  [招待有り]

  • Systemic administration of hemoglobin vesicles elevates tumor tissue oxygen tension and modifies tumor response to irradiation.

    M. Yamamoto, Y. Izumi, H. Horinouchi, Y. Teramura, H. Sakai, M. Kohno, M. Watanabe, T. Adachi, E. Ikeda, S. Takeoka, E. Tsuchida, K. Kobayashi

    J. Surg. Res.   151   48-54  2009年01月  [査読有り]

    DOI

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    22
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  • Motion of polymerized albumin particles in a model arteriole in the presence of red blood cells

    Tetsuya Tsuji, Shinji Takeoka, Yosuke Okamura, Ryo Sudo, Yasuo Ikeda, Kazuo Tanishita

    Journal of Biorheology   23 ( 1 ) 29 - 34  2009年

     概要を見る

    Polymerized albumin particles (poly Alb) with recombinant glycoprotein Ibα (rGPIbα-poly Alb) are a promising candidate for a platelet substitute. Thus, we focused on the lateral motion of poly Alb in the presence of red blood cells, because the lateral motion plays an important role in aggregate formation. We visualized the microscopic motion of poly Alb toward the immobilized ligand (von Willebrand factor, VWF) surface in a model arteriole with red blood cells with a high-speed camera. At a higher shear rate of 1,500 s-1, the concentration profile of poly Alb appeared to peak near the wall. This profile enhances the interaction between the particles and wall. Particularly the migration angle, being the angle of the poly Alb velocity vector, was enlarged near the wall and contributed to transfer of poly Alb toward the immobilized VWF surface. This tendency is desirable to achieve the adhesion of particles on the wall. © Japanese Society of Biorheology 2009.

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    1
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  • Fabrication and characterization of ultra-thin magnetic films for biomedical applications

    V. Mattoli, V. Pensabene, T. Fujie, S. Taccola, A. Menciassi, S. Takeoka, P. Dario

    PROCEEDINGS OF THE EUROSENSORS XXIII CONFERENCE   1 ( 1 ) 28 - +  2009年

     概要を見る

    Polymeric ultra-thin films, so called nanosheets, show peculiar properties making them potentially useful for several applications in biomedicine. Moreover, the possibility to functionalize these films by using different agents opens new and partially unexplored scenarios, including micro/nano sensing and actuation. This paper compares two different methods for the preparation of free-standing nanosheets, loaded with magnetic particles for no-contact manipulation in liquid environment. Morphology and functionalities of the two types of nanosheets have been characterized and compared. These magnetic nanosheets could find applications as free-standing carriers to be released and controlled in endoluminal surgery or as plasters with nanometric thickness to be delivered in situ on surgical incisions.

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    16
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  • Magnetic nanosheet adhesion to mucosal tissue

    V. Pensabene, V. Mattoli, A. Menciassi, P. Dario, T. Fujie, S. Takeoka

    2009 9TH IEEE CONFERENCE ON NANOTECHNOLOGY (IEEE-NANO)     403 - 407  2009年

     概要を見る

    Polymeric single layer nanosheets have been recently developed and proposed as drug-delivery systems. By spin coating deposition, the nanometric thickness can be easily controlled, and plenty of polymers can be deposed, thus obtaining biocompatible and resistant sheets. For all these reasons, the possibility to use them as drug carriers or "nanoplasters" for closing incisions (both externally and internally the human body) has been envisaged. One of most challenging issues is the handling and the positioning of these films within the working environment, controlling the movement of the film, possibly by using non invasive tools: the possibility to include magnetic components, such as magnetic nanoparticles or nanotubes, will pave the way for the effective use of nanosheets in the human body, by allowing precise positioning by an external magnetic field.

  • Deformability and adhesive force of artificial platelets measured by atomic force microscopy

    Toru Wada, Yosuke Okamura, Shinji Takeoka, Ryo Sudo, Yasuo Ikeda, Kazuo Tanishita

    Journal of Biorheology   23 ( 1 ) 35 - 40  2009年

     概要を見る

    Platelet glycoprotein GPIaIIa is an adhesive protein that recognizes collagen. We have investigated polymerized albumin particles conjugated with recombinant GPIaIIa (rGPIaIIa-poly Alb) for their platelet-like function. To evaluate the feasibility of these particles to achieve the hemostatic process, we measured the deformability (Young's modulus and spring constant) and the adhesive force of the particles using atomic force microscopy, which can measure the mechanical properties of individual cells. Our results showed that the Young's modulus of these particles was 2.3-fold larger than that of natural platelets and 12-fold larger than that of human red blood cells. The Young's modulus of the particles may have been determined by the properties of the polymerized albumin particle, although the glycoprotein of the platelet surface also contributed to the higher modulus. Our results also showed that the adhesive force of the rGPIaIIa-poly Alb with the collagen ligand was 52% of that of natural platelets. These two mechanical properties (deformability and adhesive force) of cells or particles, such as rGPIaIIa-poly Alb, are important specifications for the optimum design of platelet substitutes. © Japanese Society of Biorheology 2009.

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    6
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  • ナノメディシンに向けた医用材料の開発の現状と展望

    武岡 真司

    東京女子医科大学雑誌     96 - 102  2009年

  • Development of biodegradable nanosheets as nanoadhesive plaster

    Shinji Takeoka, Yosuke Okamura, Toshinori Fujie, Yoshihito Fukui

    PURE AND APPLIED CHEMISTRY   80 ( 11 ) 2259 - 2271  2008年11月

     概要を見る

    Sheet-shaped carriers having both obverse and reverse surfaces (thus, a large contact area for targeting a site and adhesive properties without any chemical cross-linker onto tissue surface) have several advantages as surgical dressings. These advantages include active targeting over spherically shaped carriers, which thus have an extremely small contact area for targeting sites. Here, we propose a novel methodology for preparation of a freestanding, ultra-thin, and biocompatible polymer nanosheet having heterosurfaces, fabricated through macromolecular assembly. In the context of biomedical applications, the targeted properties include injectable sheet-shaped drug carriers having precisely controlled size by exploiting micropatterned substrate, and giant polymer nanosheets composed of biocompatible polysaccharides. A huge aspect ratio, in excess of 10(6), is particularly applicable for novel surgical dressings. These biocompatible polymer nanosheets having heterosurfaces can thus be regarded as new biomaterials for minimally invasive treatment.

    DOI

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    20
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  • NO and CO binding profiles of hemoglobin vesicles as artificial oxygen carriers

    Hiromi Sakai, Atsushi Sato, Peter Sobolewski, Shinji Takeoka, John A. Frangos, Koichi Kobayashi, Marcos Intaglietta, Eishun Tsuchida

    BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS   1784 ( 10 ) 1441 - 1447  2008年10月

     概要を見る

    Hemoglobin vesicles (HbVs) are artificial oxygen carriers encapsulating purified and concentrated Hb solution in phospholipid vesicles (liposomes). We examined in-vitro reaction profiles of a formulation of HbV with NO and CO in anaerobic and aerobic conditions using stopped-flow spectrophotometry and a NO electrode. Reaction rate constants of NO to deoxygenated and oxygenated HbV were considerably smaller than those of cell-free Hb because of the intracellular NO-diffusion barrier. The reaction of CO with deoxygenated HbV was slightly slower than that of cell-free Hb solely because of the co-encapsulated allosteric effector, pyridoxal 5'-phosphate. The NO depletion in an aerobic condition in the presence of empty vesicles was monitored using a NO electrode, showing that the hydrophobic bilayer membrane of HbV, which might have higher gas solubility, does not markedly facilitate the O-2 and NO reaction, and that the intracellular Hb is the major component of NO depletion. In conclusion, HbV shows retarded gas reactions, providing some useful information to explain the absence of vasoconstriction and hypertension when they are intravenously injected. (c) 2008 Elsevier B.V. All rights reserved.

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    26
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  • Fibrinogen γ-chain peptide-coated, adenosine diphosphate-incorporated liposomes as a synthetic platelet substitute

    Handa, M, Okamura, Y, Takeoka, S, Ikeda, Y

    Transfusion   48 ( 2 ) 6A - 6A  2008年09月

  • POLY 88-Coordinative helical nanoporous polymer fabricated by template polymerization of hydrogen-bonded columnar liquid crystal

    Ishihara Shinsuke, Furuki Yusuke, Takeoka Shinji

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   236  2008年08月  [査読有り]

  • Helical arrangement of a hydrogen-bonded columnar liquid crystal induced by a centered triphenylene derivative bearing chiral side-chains

    Shinsuke Ishihara, Yusuke Furuki, Shinji Takeoka

    POLYMERS FOR ADVANCED TECHNOLOGIES   19 ( 8 ) 1097 - 1104  2008年08月

     概要を見る

    A hydrogen-bonded helical columnar liquid crystal was synthesized, in which the helical structure is induced by a centered triphenylene derivative bearing chiral side-chains. The triphenylene derivative, 2,6,10-tris(carboxymethoxy)-3,7,11-tris((S)-(-)-2-methyl-1-butanoxy)triphenylene (TPC4(S)), and a dendric amphiphile, 3,5-bis-(3,4-bis-dodecyloxy-benzyloxy)-N-pyridine-4-yl-benzamide (DenC12), were mixed in a 1:3 ratio to obtain a complex, TPC4(S)-DenC12. Analyses by H-1-NMR spectroscopy, diffusion ordered spectroscopy (DOSY), CD spectroscopy, infrared (IR) spectroscopy, polarized optical microscopy (POM), differential scanning calorimetry (DSC), and X-ray diffractometry revealed that TPC4(S)-DenC12 self-assembles to form helical columnar stacks in solution and a helical columnar liquid crystal in bulk. The hydrogen bonding between TPC4(S) and DenC12 is essential for the helical columnar organization, and the preference for a one-handed helical conformation is likely derived from the steric interaction between the chiral side-chains and the dendric amphiphiles in the packing of the hydrogen-bonded columnar assemblies. Copyright C(-) 2008 John Wiley & Sons, Ltd.

    DOI

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    12
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  • Haemostatic effects of polymerized albumin particles carrying fibrinogen gamma-chain dodecapeptide as platelet substitutes in severely thrombocytopenic rabbits

    Y. Okamura, T. Fujie, M. Nogawa, H. Maruyama, M. Handa, Y. Ikeda, S. Takeoka

    TRANSFUSION MEDICINE   18 ( 3 ) 158 - 166  2008年06月

     概要を見る

    Our purpose was to produce a platelet substitute that could enhance haemostatic ability using rabbits with severe thrombocytopenia. We have developed polymerized albumin particles (polyAlb) for treatment of bleeding and focused on a dodecapeptide, HHLGGAKQAGDV (H12), as a useful ligand for activated platelet. This sequence occurs only at the carboxy-terminus of the fibrinogen gamma-chain (gamma 400-411). H12 was conjugated to the surface of polyAlb modified with poly(ethylene glycol) (PEG) chains to produce blood-compatible particles (H12-PEG-polyAlb) that had prolonged blood residence time and enhanced stability in vitro and in vivo. The H12-PEG-polyAlb was administered intravenously to rabbits with severe thrombocytopenia, and the ear bleeding time was measured in order to evaluate the haemostatic effect. The H12-PEG-polyAlb significantly shortened the ear bleeding time of severely thrombocytopenic rabbits and showed no effect on the inhibition or promotion of endogenous and exogenous coagulation activities. Furthermore, we could assess the haemostatic capacity of the H12-PEG-polyAlb, based on the relationship between transfused platelet count and the bleeding time. The H12-PEG-polyAlb may be a suitable candidate for an alternative to human platelet concentrates infused to treat bleeding in patients with severe thrombocytopenia.

    DOI

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    27
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  • Evaluation of cationic assemblies constructed with amino acid based lipids for plasmid DNA delivery

    Yosuke Obata, Daisuke Suzuki, Shinji Takeoka

    BIOCONJUGATE CHEMISTRY   19 ( 5 ) 1055 - 1063  2008年05月

     概要を見る

    We synthesized cationic lipids bearing lysine, histidine, or arginine as a cationic headgroup for use in gene transfer studies. The cationic assemblies formed from lysine- or arginine-type lipids gave unilamellar vesicles (similar to 100 nm diameter), whereas the morphology of the histidine-type lipids was tube-like. The competences of the cationic assemblies were sufficient to form lipoplexes, and the resulting lipoplexes were evaluated in terms of gene expression efficiencies with COS-7 cells. The lysine- or arginine-type lipids exhibited higher gene expression efficiencies than that of Lipofectamine2000, a conventional transgenic reagent, indicating that stable lipoplexes could be prepared between spherical cationic assemblies and plasmid DNA. The gene expression efficiency in relation to the cationic headgroup of the lipids was as follows: lysine &gt;= arginine &gt; histidine. In addition, gene expression efficiency was enhanced by decreasing the length of the alkyl chain of the hydrophobic moiety. Unlike Lipofectamine2000, no reduction in transfection efficiency in the presence of fetal bovine serum was observed for the lipoplexes formed using synthetic cationic lipids. Moreover, the synthetic cationic lipids revealed remarkably low cytotoxicity compared with Lipofectamine2000. In conclusion, cationic assemblies formed from 1,5ditetradecyl-N-lysyl-L-glutamate or 1,5-ditetradecyl-N-arginyl-L-glutamate can be used as an effective plasmid DNA delivery system.

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    88
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  • Magnetic driven alginate nanoparticles for targeted drug delivery

    Gianni Ciofani, Vittoria Raffa, Yosuke Obata, Arianna Menciassi, Paolo Dario, Shinji Takeoka

    CURRENT NANOSCIENCE   4 ( 2 ) 212 - 218  2008年05月

     概要を見る

    The aim of this paper is to develop highly magnetized, biodegradable and biocompatible, polymeric nanoparticles for drug delivery in cell therapy. Alginate magnetic nanoparticles are realized by an emulsion/reticulation technique, after the dispersion of magnetite in an alginate solution. Such nanoparticles are characterized in terms of external morphology (FIB imaging), microstructure (TEM imaging), size distribution, zeta potential, magnetic properties (SQUID analysis) and drug release behaviour. Magnetization curves show the typical trend of superparamagnetic materials. Important parameters, such as magnetic permeability and magnetic momentum, are derived by employing Langevin theory. Experimental results reveal that a bi-exponential model fully describes the drug release. Finally, in vitro experiments on NIH/3T3 cells are carried out and demonstrate that our magnetic alginate nanoparticles can effectively drive the drug delivery towards an external magnetic field source.

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    24
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  • 高ずり応答血栓指向性ナノ粒子の開発

    是永 真規, 斉藤 浩, 梅村 昭男, 田川 俊明, 巌 徹, 千葉 雅俊, 野田 宗宏, 宮野 憲美, 谷口 友美, 神波 亜矢子, 服部 眞次, 岡村 陽介, 武岡 真司, 鈴木 英紀, 梶村 眞弓, 末松 誠, 横山 健次, 村田 満, 半田 誠, 池田 康夫

    薬剤学: 生命とくすり   68 ( Suppl. ) 174 - 174  2008年04月

  • Fabrication of free-standing nanoparticle-fused nanosheets and their hetero-modification using sacrificial film

    Yosuke Okamura, Saori Utsunomiya, Hidenori Suzuki, Daisuke Niwa, Tetsuya Osaka, Shinji Takeoka

    COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS   318 ( 1-3 ) 184 - 190  2008年04月

     概要を見る

    Sheet-shaped carriers, having obverse and reverse surfaces and thus a large contact area as a targeting site, have several advantages over spherical-shaped carriers, which have an extremely small contact area. Herein is proposed a novel method for the preparation of free-standing nanoparticle-fused nanosheets having uniform micrometer shape, nanometer thickness and heterogenous surfaces, using a water-soluble sacrificial film. This was achieved by combination of four processes: (1) specific adsorption of latex beads at pH 5.0 and a concentration of 1.0 x 10(11) mL(-1) onto a patterned dodecyltrimethoxysilane self-assembled monolayer (DTS-SAM) region by a conventional dry patterning process, (2) fabrication of the latex bead-sheet via thermal-fusion at 110 degrees C for 60s, (3) preparation of the free-standing nanosheet by detachment from the DTS-SAM, and (4) hetero-modification of the resulting nanosheet using a water-soluble poly(acrylic acid) as a sacrificial supporting film. Thus, this sheet-shaped carrier having hetero-surfaces can be regarded as a new material for delivery of drugs, hemostatic reagents and as wound dressings for bum injury, etc. (C) 2007 Elsevier B.V. All rights reserved.

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    19
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  • Loading of curcumin into macrophages using lipid-based nanoparticles

    Keitaro Sou, Shunsuke Inenaga, Shinji Takeoka, Eishun Tsuchida

    INTERNATIONAL JOURNAL OF PHARMACEUTICS   352 ( 1-2 ) 287 - 293  2008年03月

     概要を見る

    Curcumin (1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione, Cm) is a natural compound which possesses antioxidant, anti-inflammatory and anti-tumor ability. Here, phospholipid vesicles or lipid-nanospheres embedding Cm (CmVe or CmLn) were formulated to deliver Cm into tissue macrophages through intravenous injection. Cm could be solubilized in hydrophobic regions of these particles to form nanoparticle dispersions, and these formulations showed ability to scavenge reactive oxygen species as antioxidants in dispersions. At 6 h after intravenous injection in rats via the tail vein (2 mg Cm/kg bw), confocal microscopic observations of tissue sections showed that Cm was massively distributed in cells assumed as macrophages into the bone marrow and spleen. Taken together, these results indicate that the lipid-based nanoparticulates provide improved intravenous delivery of Cm to tissues macrophages, specifically bone marrow and splenic macrophages in present formulation, which has therapeutic potential as an antioxidant and anti-inflammatory. (C) 2007 Elsevier B.V. All rights reserved.

    DOI

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    169
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  • 特集: 血小板をつくろう -血小板代替物-

    半田 誠, 岡村 陽介, 武岡 真司, 池田 康夫

    日本血栓止血学会誌   19   774 - 778  2008年  [査読有り]

  • 生体吸収性高分子ナノシートの構築と新しい医用材料としての展開

    岡村 陽介, 藤枝 俊宣, 武岡 真司

    化学工業   59 ( 11 ) 825 - 831  2008年  [招待有り]

    CiNii

  • Encapsulation of concentrated hemoglobin solution in phospholipid vesicles retards the reaction with NO, but not CO, by intracellular diffusion barrier

    Hiromi Sakai, Atsushi Sato, Kaoru Masuda, Shinji Takeoka, Eishun Tsuchida

    JOURNAL OF BIOLOGICAL CHEMISTRY   283 ( 3 ) 1508 - 1517  2008年01月

     概要を見る

    One physiological significance of the red blood cell (RBC) structure is that NO binding of Hb is retarded by encapsulation with the cell membrane. To clarify the mechanism, we analyzed Hb-vesicles (HbVs) with different intracellular Hb concentrations, [Hb] in, and different particle sizes using stopped-flow spectrophotometry. The apparent NO binding rate constant, k(on)'((NO)), of HbV at [Hb](in) = 1 g/dl was 2.6 x 10(7) M-1 s(-1), which was almost equal to k(on)((NO)) of molecular Hb, indicating that the lipid membrane presents no obstacle for NO binding. With increasing [Hb] in to 35 g/dl, k(on)'((NO)) decreased to 0.9 x 10(7) M-1 s(-1), which was further decreased to 0.5 x 10(7) M-1 s(-1) with enlarging particle diameter from 265 to 452 nm. For CO binding, which is intrinsically much slower than NO binding, k(on)'((CO)) did not change greatly with [Hb] in and the particle diameter. Results obtained using diffusion simulations coupled with elementary binding reactions concur with these tendencies and clarify that NO is trapped rapidly by Hb from the interior surface region to the core of HbV at a high [Hb] in, retarding NO diffusion toward the core of HbV. In contrast, slow CO binding allows time for further CO- diffusion to the core. Simulations extrapolated to larger particles (8 mu m) showing retardation even for CO binding. The obtained k(on)'((NO)) and k(on)'((CO)) yield values similar to those reported for RBCs. In summary, the intracellular, not extracellular, diffusion barrier is predominant due to the rapid NO binding that induces a rapid sink of NO from the interior surface to the core, retarding further NO diffusion and binding.

    DOI

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    68
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  • 医用材料としての高分子超薄膜(ナノシート)の構築

    藤枝 俊宣, 岡村 陽介, 武岡 真司

    コンバーティック   10 ( 10 ) 137 - 143  2008年

    CiNii

  • 高分子ナノシートの構築と新しい医用材料としての展開

    岡村 陽介, 藤枝 俊宣, 武岡 真司

    化学工業   59   1 - 7  2008年

  • Novel Polymeric Nanosheets for Gerontic Applications

    Takeoka, S, Fukui, Y, Fujie, T, Okamura, Y

    Gerontechnology   7   220 - 224  2008年

  • 血液の仕組みと人工血液(血液代替物)へのアプローチ

    武岡 真司, 岡村 陽介

    化学と教育   56 ( 6 ) 2 - 5  2008年

     概要を見る

    輸血療法は,救急救命の中で重要な位置を占めている。しかし,保存期間が短い献血血液に依存している現状では,世界最高水準を誇る輸血システムであっても,血液型不適合や感染のリスクをゼロにはできず,少子高齢化による献血不足の深刻化や大災害の時への備蓄や経済問題など,多くの問題を抱えている。血液の機能の一部を補充でき,安全な人工血液(血液代替物)が開発されれば,医療に対する貢献度は大きい。最先端の分子集合技術を用いて実用可能な血液代替物(ここでは,赤血球代替物,血小板代替物)が開発されつつある。

    DOI CiNii

  • 人工血小板の開発

    岡村 陽介, 武岡 真司, 半田 誠, 池田 康夫

    Medical Science Digest,   3   138 - 140  2008年

  • Ubiquitous transference of a free-standing polysaccharide nanosheet with the development of a nano-adhesive plaster

    Toshinori Fujie, Yosuke Okamura, Shinji Takeoka

    ADVANCED MATERIALS   19 ( 21 ) 3549 - +  2007年11月

     概要を見る

    A free-standing polysaccharide nanosheet prepared by using a spin-coating-assisted layer-by-layer method is transferred from silicone rubber onto human skin (see figure) by fabricating a three-layered 'nano-adhesive plaster' involving a water-soluble sacrificial layer. By using this novel technique, conventional ultrathin films can be made without the need for a solid substrate.

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    134
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  • Rheological properties of hemoglobin vesicles (artificial oxygen carriers) suspended in a series of plasma-substitute solutions

    Hiromi Sakai, Atsushi Sato, Shinji Takeoka, Eishun Tsuchida

    LANGMUIR   23 ( 15 ) 8121 - 8128  2007年07月

     概要を見る

    Hemoglobin vesicles (HbV) or liposome-encapsulated Hbs are artificial oxygen carriers that have been developed for use as transfusion alternatives. The extremely high concentration of the HbV suspension (solutes, ca. 16 g/dL; volume fraction, ca. 40 vol %) gives it an oxygen-carrying capacity that is comparable to that of blood. The HbV suspension does not possess a colloid osmotic pressure. Therefore, HbV must be suspended in or co-injected with an aqueous solution of a plasma substitute (water-soluble polymer), which might interact with HbV. This article describes our study of the rheological properties of HbV suspended in a series of plasma substitute solutions of various molecular weights: recombinant human serum albumin (rHSA), dextran (DEX), modified fluid gelatin (MFG), and hydroxylethyl starch (HES). The HbV suspended in rHSA was nearly Newtonian. Other polymersHES, DEX, and MFGinduced HbV flocculation, possibly by depletion interaction, and rendered the suspensions as non-Newtonian with a shear-thinning profile (10(-4)-10(3) s(-1)). These HbV suspensions showed a high storage modulus (G') because of the presence of flocculated HbV. However, HbV suspended in rHSA exhibited a very low G'. The viscosities of HbV suspended in DEX, MFG, and high-molecular-weight HES solutions responded quickly to rapid step changes in shear rates of 0.1-100 s(-1) and a return to 0.1 s(-1), indicating that flocculation is both rapid and reversible. Microscopically, the flow pattern of the flocculated HbV that perfused through microchannels (4.5 mu m deep, 7 mu m wide, 20 cmH(2)O applied pressure) showed no plugging. Furthermore, the time required for passage was simply proportional to the viscosity. Collectively, the HbV suspension viscosity was influenced by the presence of plasma substitutes. The HbV suspension provides a unique opportunity to manipulate rheological properties for various clinical applications in addition to its use as a transfusion alternative.

    DOI

  • Prolonged hemostatic ability of polyethylene glycol-modified polymerized albumin particles carrying fibrinogen gamma-chain dodecapeptide

    Yosuke Okamura, Toshinori Fujie, Hitomi Maruyama, Makoto Handa, Yasuo Ikeda, Shinji Takeoka

    TRANSFUSION   47 ( 7 ) 1254 - 1262  2007年07月

     概要を見る

    BACKGROUND: Second-gene ration platelet (PLT) substitutes for treatment of bleeding were studied and the focus was on a dodecapeptide, HHLGGAKQAGDV (H12), which is a fibrinogen gamma-chain carboxy-terminal sequence (gamma 400-411) and exists only in a fibrinogen domain.
    STUDY DESIGN AND METHODS: H12 was conjugated to the surface of polymerized albumin particles (polyAlb) modified with polyethylene glycol (PEG) chains to produce biocompatible particles (H12-PEG-polyAlb) that had prolonged blood circulation t(1/2) and were more stable in vitro and in vivo compared with H12-polyAlb (not modified with PEG). H12-PEG-polyAlb was administered intravenously into thrombocytopenic rats and the t(1/2) of the particles and the tail bleeding time were measured to evaluate the prolongation in the hemostatic effect.
    RESULTS: H12-PEG-polyAlb particles modified with PEG prolonged the t1/2 and maintained specific binding ability to activated PLTs. The particles dose dependently shortened the tail bleeding time of thrombocytopenic rats 6 hours after injection.
    CONCLUSION: H12-PEG-polyAlb may be a suitable candidate for treatment of bleeding into thrombocytopenic patients as an alternative to PLT concentrate transfusion.

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  • Synthesis of porphyrins bearing uracyl groups and their assembly induced by melamine derivatives

    Satoshi Arai, Hiroki Ohshiro, Hiroyuki Nishide, Shinji Takeoka

    POLYMERS FOR ADVANCED TECHNOLOGIES   18 ( 6 ) 497 - 501  2007年06月

     概要を見る

    Self-assembled porphyrins via noncovalent bonding have attracted wide-ranging researchers in material science. We reported herein the synthesis of the tetraphenyl porphyrin derivatives bearing uracyl groups as acceptor-donor-acceptor (ADA) type hydrogen bonding units, through the condensation of 5,10- or 5,15-bis (3-amino-4-ethylhexylphenyl) porphyrin derivatives with 6-carboxyuracyl derivatives. When two porphyrins having uracyl groups at the different substituted positions were respectively mixed with a melamine derivative in benzene, H-1 NMR spectra showed that the 5,15 substituted uracyl porphyrin formed a hydrogen-bonded suprastructure with the melamine derivative as a complementary molecule to the uracyl moiety, although the other 5,10-substituted uracylporphyrin could not form such a structure. The SEM observation indicated that the mixture with the 5,15-substituted uracyl porphyrin and the melamine with long alkyl chains formed a sheet-like structure. Copyright (C) 2007 John Wiley & Sons, Ltd.

    DOI

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    3
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  • Selective uptake of surface-modified phospholipid vesicles by bone marrow macrophages in vivo

    Keitaro Sou, Beth Goins, Shinji Takeoka, Eishun Tsuchida, William T. Phillips

    BIOMATERIALS   28 ( 16 ) 2655 - 2666  2007年06月

     概要を見る

    An advantage of using vesicles (liposomes) as drug delivery carriers is that their pharmacokinetics can be controlled by surface characteristics, which can permit specific delivery of the encapsulated agents to organs or cells it? vivo. Here we report a vesicle formulation which targets the bone marrow after intravenous injection in rabbits. Surface modification of the vesicle with an anionic amphiphile; L-glutamic acid, N-(3-carboxy-1-oxopropyl)-, 1,5- dihexadecyl ester (SA) results in significant targeting of vesicles to bone marrow. Further incorporation of as little as 0.6 mol% of poly(ethylene glycol)-lipid (PEG-DSPE) passively enhanced the distribution of SA-vesicles into bone marrow and inhibited hepatic uptake. In this model, more than 60% of the intravenously injected vesicles were distributed to bone marrow within 6 h after administration of a small dose of lipid (15 mg/kg b.w.). Histological evidence indicates that the targeting was achieved due to uptake by bone marrow macrophages (BMM phi). The efficient delivery of encapsulated scintigraphic and fluorescent imaging agents to BMM phi suggests that vesicles are promising carriers for the specific targeting of BMM phi and may be useful for delivering a wide range of therapeutic agents to bone marrow. (c) 2007 Elsevier Ltd. All rights reserved.

    DOI

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  • A hydrogen-bonded supramolecular hexagonal columnar liquid crystal composed of a tricarboxylic triphenylene and monopyridyl dendrons

    Shinsuke Ishihara, Yuusuke Furuki, Shinji Takeoka

    CHEMISTRY LETTERS   36 ( 2 ) 282 - 283  2007年02月

     概要を見る

    Tricarboxylic triphenylene (TPC5) and monopyridyl dendron (DenC12) were mixed in 1:2, 1:3, and 1:4 molar ratios, and investigation by IR, DSC, and XRD studies proved that TPC5 and DenC12 self-assembled to form a hexagonal columnar liquid crystal with 1:3 molar stoichiometry via complementary hydrogen-bonds.

    DOI

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    10
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  • Manipulation of free-standing polysaccharide nanosheets and their application on a nano-adhesive plaster

    Takeoka, S, Fujie, T, Okamura, Y

    Polym. Prepr. (Am. Chem. Soc., Div. Polym. Chem.)   48 ( 2 ) 976 - 977  2007年  [査読有り]

  • 各種代用血漿剤に分散させたヘモグロビン小胞体(人工赤血球)とその血液混合系のレオロジー特性.

    佐藤 敦, 酒井 宏水, 武岡 真司, 土田 英俊

    日本ヘモレオロジー学会誌   10   3-11  2007年  [査読有り]

  • Enzymatic elimination of hydrogen peroxide by a mthemoglobin/L-tyrosine system

    Tomoyasu Atoji, Hirotaka Yatami, Motonari Aihara, Shinji Takeoka

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND BIOTECHNOLOGY   35 ( 6 ) 555 - 567  2007年

     概要を見る

    We studied the peroxidase activity of ferrylhemoglobin radical (Hb(Fe4+ = 0*)) generated by the reaction of metHb (Hb(Fe3+)) with hydrogen peroxide (H2O2). To clarify the behaviors of ferrylHb radical, it was isolated from the reaction mixture of metHb and H2O2 by GPC at 4 degrees C. The radical species underwent rapid autoreduction to metHb at 37 degrees C accompanied with denaturation; however, it was stable for several minutes at VC. In ESR measurements, the signal of the ferrylHb radical immediately disappeared in the presence of L-Tyrosine (L-Tyr), and simultaneously, the signal of the ferric heme increased. This suggested that the ferrylHb radical immediately converted to metHb by L-Tyr even at 4 degrees C. Furthermore, dimerized L-Tyr was detected in the reaction mixture. This showed that the ferrylHb radical was reduced to metHb by electron donation from L-Tyr. The enzymatic reaction using L-Tyr as the substrate resulted in the elimination of H2O2 in this system.

    DOI

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    2
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  • Effects of hemoglobin vesicles, a liposomal artificial oxygen carrier, on hematological responses, complement and anaphylactic reactions in rats

    Hideki Abe, Hiroshi Azuma, Miki Yamaguchi, Mitsuhiro Fujihara, Hisami Ikeda, Hiromi Sakai, Shinji Takeoka, Eishun Tsuchida

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND BIOTECHNOLOGY   35 ( 2 ) 157 - 172  2007年

     概要を見る

    Hemoglobin vesicle (HbV), a liposomal oxygen carrier containing human hemoglobin, was intravenously infused into rats. After the infusion of saline, the HbV or empty vesicle (EV), numbers of red cells, leukocytes and platelets in peripheral blood were unchanged during the observation period of one week in addition to each time point among three groups. However, the lymphocyte ratio transiently decreased and the granulocyte ratio increased in the HbV and EV groups at 6 h after the infusion. Those changes returned to the initial value one day after the infusion and those were maintained for the subsequent observation period. No dramatic change was seen in the ratio of CD4(+)/CD8(+) T cells. A transient decrease of the complement titer was observed three days after the infusion of HbV and EV, although the consumption of complement titer was not detected in rat serum by mixing HbV or EV in vitro, indicating that the transient decrease of complement titer in vivo was not due to the consumption of complement due to the interaction with HbV or EV. Multiple infusions of HbV caused the decrease of complement titer only after the first infusion and no allergic reaction was observed. No anaphylactic shock was observed in rats administered with EV several times, while ovalbumin (OVA) sensitized rats died with symptoms of respiratory distress after the second OVA administration. These results indicate that HbV could be administered without serious clinical symptoms or adverse reactions.

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    27
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  • Atropisomers of meso-conjugated uracyl porphyrin derivatives and their assembling structures

    Satoshi Arai, Daisuke Niwa, Hiroyuki Nishide, Shinji Takeoka

    ORGANIC LETTERS   9 ( 1 ) 17 - 20  2007年01月

     概要を見る

    We have synthesized a 5,15 meso-substituted methyluracyl porphyrin derivative bearing 6-methyluracyl units directly at the meso positions. The atropisomerization was regulated by steric replusion between the methyl substituents. When the atropisomers were mixed with alkylated melamine as a complementary hydrogen-bonding unit, the hydrogen-bonded assemblies were analyzed by diffusion-ordered spectroscopy (DOSY) in solution, which clarified that the alpha alpha isomer formed a face-to-face dimer, whereas the alpha beta isomer took a zigzag structure.

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    15
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  • ヘモグロビン小胞体(HbV)-リコンビナントアルブミン分散溶液による40%交換輸血:ラット脾臓内HbV代謝と造血に関する2週間の観察

    酒井宏水, 堀之内宏久, 山本学, 池田 栄二, 武岡真司, 高折益彦, 土田英俊, 小林紘一

    日本輸血細胞治療学会誌(二次掲載)   53 ( 1 ) 47 - 55  2007年

     概要を見る

    (背景) 輸血代替として開発されたヘモグロビン小胞体 (HbV, 粒径251±81nm) について, 動物投与試験によりその酸素運搬機能が明らかにされてきた. しかし投与後の中長期的な回復過程, 特に細網内皮系におけるHbVの分解と造血については十分な検討が為されていなかった. (方法) Wistar系ラット (♂, 60匹) を用い, HbVを5g/dL濃度のリコンビナントアルブミン溶液 (rHSA) に分散させた溶液 (HbV/rHSA), ラット保存赤血球をrHSAに分散させた溶液 (sRBC/rHSA), 或はrHSA溶液単独で, 循環血液量の40%を急速交換した. その後最長14日間の血液学的, 血液生化学的解析, および組織病理学的検討を実施した. (結果) HbV/rHSA群とrHSA群では, 血液交換後に低下したヘマトクリット値 (Hct, 約26%) が, 7日後には交換前の値 (43%) にまで回復した. 血中エリスロポエチン濃度は, 全群で上昇した. 特にrHSA群で1日後に最も高い値を示し (321±123IU/L), 貧血状態を反映したと考えられた (HbV/rHSA, 153±22 ; sRBC/rHSA, 63±7 ; baseline, 21±3). また, 同時に全群で脾臓肥大を認めた (HbV/rHSA>rHSA>sRBC/rHSA). 組織病理学的観察から, 脾臓に捕捉されたHbVは14日以内に完全に消失した. しかし, ヘモジデリン沈着がHbV/rHSA群およびsRBC/rHSA群に認められた. また, rHSA群とHbV/rHSA群の赤脾髄に多量の赤芽球が存在した. (結論) 40%交換輸血において, 脆弱な赤血球が細網内皮系で捕捉分解される生理的機序と同様の経路を経て, HbVが捕捉代謝される過程が予想された. また, 造血機能の亢進によりHctが7日以内に完全に支障無く回復することを確認した.

    DOI CiNii

  • Development of Nano-Biotechnology; from Artificial Platelets to Nano-Adhesive Plasters

    S. Takeoka

    The 4th 21COE International Symposium on “Practical Nano-Chemistry”, Tokyo   Program and Abstracts   5 - 5  2006年12月

  • Cooperative Effects of Platelets Aggregation of Platelet Substitutes at High Shear Rates;Mixed System of Fibrinogen gamma-Chain Dodecapeptide- or Glycoprotein Ibalpha-Conjugated Latex Beads under Flow Conditions

    Okamura, Y, Suzuki, H, Tsuchida, E, Handa, M, Ikeda, Y, Takeoka, S

    J. Artif. Organs   9 ( 4 ) 251 - 258  2006年12月

    DOI PubMed

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    33
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  • ナノ絆創膏の開発-ヘテロな表裏を持つ生分解ナノシートの開発-

    武岡真司

    第28回生体膜と薬物の相互作用シンポジウム ランチョンセミナー, 静岡    2006年11月

  • Hemoglobin vesicles containing methemoglobin and L-tyrosine to suppress methemoglobin formation in vitro and in vivo

    Tomoyasu Atoji, Motonari Aihara, Hiromi Sakai, Eishun Tsuchida, Shinji Takeoka

    BIOCONJUGATE CHEMISTRY   17 ( 5 ) 1241 - 1245  2006年09月

     概要を見る

    Hemoglobin (Hb) vesicles have been developed as cellular-type Hb-based O-2 carriers in which a purified and concentrated Hb solution is encapsulated with a phospholipid bilayer membrane. Ferrous Hb molecules within an Hb vesicle were converted to ferric metHb by reacting with reactive oxygen species such as hydrogen peroxide (H2O2) generated in the living body or during the autoxidation of oxyHb in the Hb vesicle, and this leads to the loss of O-2 binding ability. The prevention of metHb formation by H2O2 in the Hb vesicle is required to prolong the in vivo O-2 carrying ability. We found that a mixed solution of metHb and L-tyrosine (L-Tyr) showed an effective H2O2 elimination ability by utilizing the reverse peroxidase activity of metHb with L-Tyr as an electron donor. The time taken for the conversion of half of oxyHb to metHb (T-50) was 420 min for the Hb vesicles containing 4 g/dL (620 mu M) metHb and 8.5 mM L-Tyr ((metHb/L-Tyr) Hb vesicles), whereas the time of conversion for the conventional Hb vesicles was 25 min by stepwise injection of H2O2 (310 mu M) in 10 min intervals. Furthermore, in the (metHb/L-Tyr) Hb vesicles, the metHb percentage did not reach 50% even after 48 h under a pO(2) of 40 Torr at 37 degrees C, whereas T-50 of the conventional Hb vesicles was 13 h under the same conditions. Moreover, the T-50 values of the conventional Hb vesicles and the (metHb/L-Tyr) Hb vesicles were 14 and 44 h, respectively, after injection into rats (20mL/kg), confirming the remarkable inhibitory effect of metHb formation in vivo in the (metHb/L-Tyr) Hb vesicles.

    DOI

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    21
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  • Hemoglobin vesicles containing methemoglobin and L-tyrosine to suppress methemoglobin formation in vitro and in vivo

    Tomoyasu Atoji, Motonari Aihara, Hiromi Sakai, Eishun Tsuchida, Shinji Takeoka

    BIOCONJUGATE CHEMISTRY   17 ( 5 ) 1241 - 1245  2006年09月

     概要を見る

    Hemoglobin (Hb) vesicles have been developed as cellular-type Hb-based O-2 carriers in which a purified and concentrated Hb solution is encapsulated with a phospholipid bilayer membrane. Ferrous Hb molecules within an Hb vesicle were converted to ferric metHb by reacting with reactive oxygen species such as hydrogen peroxide (H2O2) generated in the living body or during the autoxidation of oxyHb in the Hb vesicle, and this leads to the loss of O-2 binding ability. The prevention of metHb formation by H2O2 in the Hb vesicle is required to prolong the in vivo O-2 carrying ability. We found that a mixed solution of metHb and L-tyrosine (L-Tyr) showed an effective H2O2 elimination ability by utilizing the reverse peroxidase activity of metHb with L-Tyr as an electron donor. The time taken for the conversion of half of oxyHb to metHb (T-50) was 420 min for the Hb vesicles containing 4 g/dL (620 mu M) metHb and 8.5 mM L-Tyr ((metHb/L-Tyr) Hb vesicles), whereas the time of conversion for the conventional Hb vesicles was 25 min by stepwise injection of H2O2 (310 mu M) in 10 min intervals. Furthermore, in the (metHb/L-Tyr) Hb vesicles, the metHb percentage did not reach 50% even after 48 h under a pO(2) of 40 Torr at 37 degrees C, whereas T-50 of the conventional Hb vesicles was 13 h under the same conditions. Moreover, the T-50 values of the conventional Hb vesicles and the (metHb/L-Tyr) Hb vesicles were 14 and 44 h, respectively, after injection into rats (20mL/kg), confirming the remarkable inhibitory effect of metHb formation in vivo in the (metHb/L-Tyr) Hb vesicles.

    DOI

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    21
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  • POLY 234-Preparation of freestanding nano-adhesive plasters having hetero-surfaces

    Shinji Takeoka, Yosuke Okamura

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   232   234  2006年09月

  • POLY 481-Hemostatic effects of polymerized albumin nano-particles carrying fibrinogen g-chain dodecapeptide as platelet substitutes

    Yosuke Okamura, Toshinori Fujie, Makoto Handa, Yasuo Ikeda, Shinji Takeoka

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   232   481  2006年09月

  • Novel Approaches to Develop Artificial Platelets / Platelet Substitutes (S12−2)

    S. Takeoka

    The 4th Asian-Pacific Congress on Thrombosis and Hemostasis, Suzhou   Abstract Book   48  2006年09月

  • 分子集合科学を利用した人工血球の創製とその応用

    武岡真司

    第43回茅コンファレンス、山梨    2006年08月

  • 血小板代替物の開発

    武岡真司, 岡村陽介

    バイオインダストリー   23 ( 7 ) 65 - 71  2006年07月

    CiNii

  • 分子集合化学を用いた人工血小板の研究展開—ナノバイオテクノロジーへの挑戦—

    武岡真司

    第3回ニューマテリアル研究会、滋賀    2006年06月

  • “Design and Preparation of Blood Substitutes Using Molecular Assembling Technologies”,

    S. Takeoka

    3rd IUPAC-sponsored International Symposium on Macro- and Supramolecular Architectures and Materials (MAM-06), Tokyo   Program and Abstracts   71  2006年05月

  • Development of Nano Band-Aid Adhereing To A Wound From Inside of A Blood Vessel

    S. Takeoka

    BASF Workshop Nanostructured Surfaces, Shanghai   Abstract   84  2006年05月

  • Design and Preparation of Blood Substitutes Using Molecular Assembling Technologies

    S. Takeoka

    3rd IUPAC-sponsored International Symposium on Macro- and Supramolecular IUPAC-sponsored International Symposium on Macro- and Supramolecular Architectures and Materials (MAM-06), Waseda Univ., Tokyo, JAPAN   Program and Abstracts   71  2006年05月

  • 血管の内側から傷口に貼るナノ絆創膏の開発

    武岡真司

    国際BIO EXPO バイオ アカデミック フォーラム、東京ビックサイト    2006年05月

  • 分子集合科学を利用した人工血液の創製

    武岡真司

    人工血液   13 ( 4 ) 136 - 147  2006年04月

  • 血小板代替物の開発の現状

    岡村陽介, 藤枝俊宣, 半田誠, 池田康夫, 武岡真司

    人工血液   13 ( 4 ) 155 - 160  2006年04月

  • 1.人工血液はどこまで出来ているのか、2.早稲田大学理工学部の新たな出発

    武岡真司

    「夢のたまご塾」飛騨アカデミー、ホテル季古里    2006年03月

  • 薄膜状高分子構造体とその調製 方法−ナノ絆創膏への挑戦−

    武岡真司

    Technology Link in W.T.L.O2    2006年03月

  • Acute 40 percent exchange-transfusion with hemoglobin-vesicles (HbV) suspended in recombinant human serum albumin solution: degradation of HbV and erythropoiesis in a rat spleen for 2 weeks

    H Sakai, H Horinouchi, M Yamamoto, E Ikeda, S Takeoka, M Takaori, E Tsuchida, K Kobayashi

    TRANSFUSION   46 ( 3 ) 339 - 347  2006年03月

     概要を見る

    BACKGROUND: Hemoglobin-vesicles (HbVs; diameter, 251 +/- 81 nm) are artificial O-2 carriers. Their efficacy for acute exchange transfusion has been characterized in animal models. However subsequent profiles of recovery involving the degradation of HbV in the reticuloendothelial system (RES) and hematopoiesis remain unknown.
    STUDY DESIGN AND METHODS: Isovolemic 40 percent exchange transfusion was performed in 60 male Wistar rats with HbV suspended in 5 g per dL recombinant human serum albumin (rHSA; HbV/rHSA, [Hb] = 8.6 g/dL), stored rat RBCs suspended in rHSA (sRBC/rHSA), or rHSA alone. Hematological and plasma biochemical analyses and histopathological examination focusing on the spleen were conducted for the subsequent 14 days.
    RESULTS: The reduced hematocrit (Hct) level (26%) for the HbV/rHSA and rHSA groups returned to its original level (43%) in 7 days. Plasma erythropoietin was elevated in all groups: the rHSA group showed the highest value on Day 1 (321 +/- 123 mIU/mL) relating to the anemic conditions (HbV/rHSA, 153 +/- 22; sRBC/rHSA, 63 +/- 7; baseline, 21 +/- 3). Simultaneously, splenomegaly occurred in all the groups as HbV/rHSA &gt; rHSA &gt; sRBC/rHSA. Histopathologically, the accumulated HbV in the spleen was undetectable by Day 14, but hemosiderin was deposited in slight quantities for both the HbV/rHSA and sRBC/rHSA groups. Considerable amounts of erythroblasts were apparent in the spleens of both the rHSA and the HbV/rHSA groups.
    CONCLUSION: HbVs were phagocytized and degraded in RES, a physiological compartment for the degradation of RBCs, and the elevated erythropoietic activity resulted in the complete recovery of Hct within 7 days in the rat model.

    DOI

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    30
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  • Modulation of Nanoparticles for Blood Substitutes

    S. Takeoka

    21COE International Symposium, UNIVERSITE MONTPELLIER II   Abstract   7  2006年02月

  • Preparation and evaluation of o/w emulsions with an anionic lipid, containing lipophilic drug

    Inenaga, S., Sou, K., Takeoka, S., Tsuchida, E.

    Polymer Preprints, Japan   55 ( 2 )  2006年

  • Hemoglobin vesicles as a molecular assembly. Characteristics of preparation process and performances as artificial oxygen carriers

    Hiromi Sakai, Keitaro Sou, Shinji Takeoka, Koichi Kobayashi, Eishun Tsuchida

    Blood Substitutes     514 - 522  2006年  [査読有り]

     概要を見る

    Liposome encapsulated hemoglobin is a long-sought goal in Japan, where the product is called hemoglobin vesicles (HbV), which distinguishes this product from the one developed primarily in the US, whose designation is liposome-encapsulated Hb (LEH). HbV is the result of a long series of studies in which the size of the vesicles, including the number of lipid layers, the surface composition and materials co-encapsulated have been optimized. HbV is produced by an extrusion process that has commercial potential, although at this time the product has not yet been produced in quantities sufficient for clinical trials. Sterilization of the hemoglobin, prior to encapsulation, is performed using heat, and antioxidants are co-encapsulated to retard hemoglobin oxidation. Oxygen affinity is regulated to any desired P50 by co-encapsulation of allosteric effectors, and this group has contributed important studies on the effect of different P 50 on oxygen delivery to tissues by HbV. The product is claimed to be stable when stored for up to 2 years. A commercial effort has been launched in Japan, and it is hoped that HbV could be in human clinical trials within the next few years. This chapter summarizes the characteristics of the preparation process of HbV based on the sciences of molecular assembly to induce their excellent performances. © 2006 Elsevier Ltd. All rights reserved.

    DOI

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    4
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  • Hemostatic effects of polymerized albumin nano-particles carrying fibrinogen-gamma chain dodecapeptide as platelet substitutes

    Okamura, Y, Fujie, T, Handa, M, Ikeda, Y, Takeoka, S

    Polym. Prepr. (Am. Chem. Soc., Div. Polym. Chem.)   47 ( 2 ) 854 - 855  2006年  [査読有り]

  • Interaction of hemoglobin vesicles, a cellular-type artificial oxygen carrier, with human plasma: Effects on coagulation, kallikrein-kinin, and complement systems

    H Abe, M Fujihara, H Azuma, H Ikeda, K Ikebuchi, S Takeoka, E Tsuchida, H Harashima

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND BIOTECHNOLOGY   34 ( 1 ) 1 - 10  2006年

     概要を見る

    Hemoglobin vesicles (HbVs), cellular-type artificial oxygen carriers containing human hemoglobin, were assessed for their biocompatibility by mixing with human plasma in vitro . Among three kinds of HbVs (PEG-DPEA-HbV, PEG-DPPG-HbV and DPPG-HbV), PEG-DPEA-HbV did not affect the extrinsic or intrinsic coagulation activities of the plasma, while PEG-DPPG-HbV and DPPG-HbV tended to shorten the intrinsic coagulation time. The kallikrein-kinin cascade of the plasma was slightly activated by PEG-DPPG-HbV and DPPG-HbV, but not by PEG-DPEA-HbV. The complement consumption of the plasma was observed by incubation with DPPG-HbV, but not with PEG-DPEA-HbV or PEG-DPPG-HbV. These results indicate that PEG-DPEA-HbV has a higher biocompatibility with human plasma.

    DOI

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    20
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  • Modulation of Nanoparticles for Blood Substitutes (Red Blood Cell Substitutes and Platelet Substitutes)

    S. Takeoka

    Waseda-Korea Universities' Joint Symposium on "Nanoscience and Nanotechnology"   Abstract  2006年01月

  • Host-guest assembly of pyridinium-conjugated calix[4]arene via cation–π interaction

    Ishihara, S, Takeoka, S

    Tetrahedron Letters   47 ( 2 ) 181 - 184  2006年01月

    DOI

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    37
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  • Porphyrin capped with calix[4]arene derivative via hydrogen bonds

    S Arai, H Ohkawa, S Ishihara, T Shibue, S Takeoka, H Nishide

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   78 ( 11 ) 2007 - 2013  2005年11月

     概要を見る

    A calix[4]arene-porphyrin duplex was prepared by mixing equimolar amounts of hydroxy or carboxy calix[4]arene derivatives and pyridyl or o-aminophenylporphyrin derivatives. Electrospray ionization mass spectrometry (ESI-MS) was applied to screen a suitable pair of a calix[4]arene and a porphyrin. meso-Tetra(2-pyridyl)porphyrin formed a duplex with tetrahydroxy or tetrahydroxymethylcalix[4]arene via triple or quadruple hydrogen bonds. H-1 NMR spectra showed that the tetrahydroxycalix[4]arene was symmetrically located upon the porphyrin ring, whereas trihydroxycalix[4]arene was slanted on the porphyrin ring. The duplex of meso-tetra(2-pyridyl)porphyrinatocobalt(II) and tetrahydroxymethylcalix[4]arene formed a complex with benzylimidazole, which was capable of reversible dioxygen-binding. The capping structure upon porphyrin provided by calix[4]arene raised the life-time of dioxygen-adduct compared with the porphyrin without calix[4]arene.

    DOI

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    20
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  • Hemostatic effects of phospholipid vesicles carrying fibrinogen gamma chain dodecapeptide in vitro and in vivo

    Y Okamura, Maekawa, I, Y Teramura, H Maruyama, M Handa, Y Ikeda, S Takeoka

    BIOCONJUGATE CHEMISTRY   16 ( 6 ) 1589 - 1596  2005年11月

     概要を見る

    We studied prototypes of platelet substitutes that bear on their surface a dodecapeptide, HHLG-GAKQAGDV (1112). The peptide is a fibrinogen gamma chain carboxy-terminal sequence (gamma 400-411) and recognizes specifically the active form of glycoprotein (GP) IIb/IIIa on the surface of activated platelets. We conjugated H12 to the end of poly(ethylene glycol) chains on the surface of a phospholipid vesicle with an average diameter of 220 nm to prepare H12-PEG-vesicles. The half-life of the H12-PEG-vesicles was significantly prolonged by PEG modification, and the ability of H12 on the surface of the vesicle to recognize GPIIb/IIIa was maintained even though the surface was modified with PEG chains. The H12-PEG-veiscles enhanced the in vitro thrombus formation of platelets that were adhering to a collagen-immobilized plate, when thrombocytopenia-imitation blood was passed over the plate. Based on the flow cytometric analyses of PAC-1 binding and P-selectin expression, the H12-PEG-vesicles were shown not to cause platelet activation. Furthermore, the H12-PEG-vesicles dose-dependently shortened the tail bleeding time of thrombocytopenic rats. It was confirmed that the H12-PEG-vesicles had a hemostatic effect and may be a suitable candidate for an alternative to human platelet concentrates transfused into thrombocytopenic patients.

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    55
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  • 第12回 日本血液代替物学会年次大会を開催して

    武岡真司

    人工血液   13 ( 3 ) 98 - 99  2005年11月

  • 赤血球代替物、血小板代替物の開発の現状と将来展望

    武岡真司

    第49回 日本輸血学会北海道支部会例会、北海道赤十字血液センター    2005年09月

  • 分子集合科学を利用した人工赤血球の創製とその応用

    武岡真司

    治験促進啓発シンポジウム、軽井沢万平ホテル   日本医師会治験促進センター発刊   29 - 31  2005年09月

  • 分子集合科学を利用した人工血液の創製とその応用

    武岡真司

    第43回 茅コンファレンス、大泉高原八ヶ岳ロイヤルホテル   予稿集   29  2005年08月

  • Hemostatic effects of fibrinogen gamma-chain dodecapeptide-conjugated polymerized albumin particles in vitro and in vivo

    Y Okamura, S Takeoka, Y Teramura, H Maruyama, E Tsuchida, M Handa, Y Ikeda

    TRANSFUSION   45 ( 7 ) 1221 - 1228  2005年07月

     概要を見る

    BACKGROUND: Prototypes of platelet (PLT) substitutes have been studied and the focus was on a dodecapeptide, HHLGGAKQAGDV (H12), which is a fibrinogen gamma-chain carboxy-terminal sequence (gamma 400-411) and exists only in the fibrinogen domain.
    STUDY DESIGN AND METHODS: H12 was conjugated to the surface of polymerized albumin particles (polyAlb) as biocompatible and biodegradable particles with a mean diameter of 260 +/- 60 nm, and the hemostatic ability of H12-conjugated polyAlb (H12-polyAlb) under flow conditions and thrombocytopenic rats have been studied
    RESULTS: H12-polyAlb enhanced the in vitro thrombus formation of activated PLTs on a collagen-immobilized plate when exposed to the flowing thrombocytopenic imitation blood. Furthermore, the analysis of the tail bleeding time of rats that were made thrombocytopenic by busulfan injection showed that H12-polyAlb had a hemostatic effect. Based on the bleeding time and the amount injected, the hemostatic capacity of 20 H12-polyAlb was estimated to correspond to that of one PLT.
    CONCLUSION: These results were important first steps toward the development of PLT substitutes and indicated that H12-polyAlb may be a suitable candidate for an alternative to human PIT concentrates transfused into thrombocytopenic patients in the future.

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  • Hemostatic Effects of Polymerized Albumin Particles Carrying Recombinant Glycoprotein Iba As Platelet Substitutes in vitro and in vivo

    Hemostatic Effects of Polymerized Albumin Particles Carrying Recombinant Glycoprotein Iba As Platelet Substitutes in vitro, in vivo

    The Xth International Symposium on Blood Substitutes, Brown Univ., Providence, RI, USA   Program and Abstracts   92  2005年06月

  • 血小板代替物 rGPIbαリポソームの機能評価

    斉藤 浩, 是永 真規, 野田 宗宏, 岡村 陽介, 武岡 真司, 土田 英俊, 半田 誠, 村田 満, 横山 健次, 梶村 眞弓, 末松 誠, 池田 康夫

    人工血液   13 ( 2 ) 70 - 70  2005年05月

  • 血小板代替物 人工血小板の止血機能増強,血栓性におよぼすvon Willebrand因子 GPIbαおよびコラーゲン受容体の作用の差異

    田村 典子, 後藤 信哉, 石田 英之, 武岡 真司, 岡村 陽介, 池田 康夫

    人工血液   13 ( 2 ) 71 - 71  2005年05月  [査読有り]

  • 第53回日本輸血学会、止血機能を有する微粒子系(血小板代替物)の設計と機能評価

    武岡真司

    日本輸血学会雑誌   51 ( 2 ) 140  2005年05月

  • 人工赤血球・人工血小板の開発の現状

    武岡真司

    臨床麻酔   29   721 - 726  2005年04月

  • Oxygen transport by low and normal oxygen affinity hemoglobin vesicles in extreme hemodilution

    P Cabrales, H Sakai, AG Tsai, S Takeoka, E Tsuchida, M Intaglietta

    AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY   288 ( 4 ) H1885 - H1892  2005年04月

     概要を見る

    The oxygen transport capacity of phospholipid vesicles encapsulating purified Hb (HbV) produced with a Po-2 at which Hb is 50% saturated (P-50) of 8 (HbV(8)) and 29 mmHg (HbV(29)) was investigated in the hamster chamber window model by using microvascular measurements to determine oxygen delivery during extreme hemodilution. Two isovolemic hemodilution steps were performed with 5% recombinant albumin (rHSA) until Hct was 35% of baseline. Isovolemic exchange was continued using HbV suspended in rHSA solution to a total [Hb] of 5.7 g/dl in blood. P-50 was modified by coencapsulating pyridoxal 5 '-phosphate. Final Hct was 11% for the HbV groups, with a plasma [Hb] of 2.1 +/- 0.1 g/dl after exchange with HbV(8) or HbV(29). A reference group was hemodiluted to Hct 11% with only rHSA. All groups showed stable blood pressure and heart rate. Arterial oxygen tensions were significantly higher than baseline for the HbV groups and the rHSA group and significantly lower for the HbV groups compared with the rHSA group. Blood pressure was significantly higher for the HbV(8) group compared with the HbV(29) group. Arteriolar and venular blood flows were significantly higher than baseline for the HbV groups. Microvascular oxygen delivery and extraction were similar for the HbV groups but lower for the rHSA group (P &lt; 0.05). Venular and tissue Po-2 were statistically higher for the HbV(8) vs. the HbV(29) and rHSA groups (P &lt; 0.05). Improved tissue Po-2 is obtained when red blood cells deliver oxygen in combination with a high- rather than low-affinity oxygen carrier.

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  • New generation of hemoglobin-based oxygen carriers evaluated for oxygenation of critically ischemic hamster flap tissue

    C Contaldo, J Plock, H Sakai, S Takeoka, E Tsuchida, M Leunig, A Banic, D Erni

    CRITICAL CARE MEDICINE   33 ( 4 ) 806 - 812  2005年04月

     概要を見る

    Objectives: The aim of this study was to investigate and compare the effects of a traditionally formulated, low-viscosity, right-shifted polymerized bovine hemoglobin solution and a highly viscous, left-shifted hemoglobin vesicle solution (HbV-HES) on the oxygenation of critically ischemic peripheral tissue.
    Design. Randomized, prospective study.
    Setting. University laboratory.
    Subject. A total of 40 male golden Syrian hamsters.
    Interventions: Island flaps were dissected from the back skin of anesthetized hamsters. The flap included a critically ischemic, hypoxic area that was perfused via a collateralized vasculature. One hour after completion of the preparation, the animals received a 33% blood exchange with 6% hydroxyethyl starch 200/0.5 (HES, n = 9), HbV suspended in HES (HbV-HES, n = 8), or polymerized bovine hemoglobin solution (n = 9).
    Measurements and Main Results., Three hours after the blood exchange, microcirculatory blood flow (laser-Doppler flowmetry) was increased to 262% of baseline for HbV-HES (p &lt; .01) and 197% for polymerized bovine hemoglobin solution (p &lt; .05 vs. baseline and HbV-HES). Partial tissue oxygen tension (bare fiber probes) was only improved after HbV-HES (9.4 torr to 14.2 torr, p &lt; .01 vs. baseline and other groups). The tissue lactate/pyruvate ratio (microdialysis) was elevated to 51 in the untreated control animals, and to 34 +/- 8 after HbV-HES (p &lt; .05 vs. control) and 38 +/- 11 after polymerized bovine hemoglobin solution (not significant).
    Conclusions. Our study suggests that in critically ischemic and hypoxic collateralized peripheral tissue, oxygenation may be improved by normovolemic hemodilution with HbV-HES. We attributed this improvement to a better restoration of the microcirculation and oxygen delivery due to the formulation of the solution.

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  • 機能性分子素子としての人工赤血球・人工血小板の構築

    武岡真司

    日本顕微鏡学会関東支部 第29回 講演会   予稿集   15  2005年03月

  • 823 人工血小板の輸送と粘着(J13-1 生体の熱・物質輸送とその応用(1),J13 生体の熱・物質輸送とその応用,2005年度年次大会)

    鈴木 健一, 藤田 英輝, 緒方 亜美, 田村 典子, 後藤 信哉, 武岡 真司, 池田 康夫, 谷下 一夫

    年次大会講演論文集   2005   49 - 50  2005年

     概要を見る

    We examined how the deformability of the particle influenced on the adhesion of particle to vWf surface, the concentration profile in flow channel and the dispersion coefficient in vitro for developing the artificial platelet substitute. We employed recombinant GlycoproteinIbα conjugated Latex Beads (rGPIbα-LB) and rGPIbα conjugated phospholipid vesicles (rGPIbα-vesicles) as platelet substitute. These particles were observed at high wall shear rate (1500 s^<-1>) with a 40% hematocrit in rectangular flow channel (height and width were 200μm), which had von Willebrand factor (vWf) surface. The rGPIbα-LB adhered to vWf surface firmly, but rGPIbα-vesicle repeated attaching to vWf surface and detaching from vWf surface. The concentration-peak of rGPIbα-LB was near vWf surface more than that of rGPIbα-vesicle. This result shows that rGPIbα-LB existed near vWf wall more than rGPIbα-vesicle. It is considered that this characteristic makes rGPIbα-LB easier to attach to vWf surface than rGPIbα-vesicle. The mobility of rGPIbα-vesicle is bigger than rGPIbα-LB in blood flow, because the dispersion coefficient of rGPIbα-vesicle was bigger than that of rGPIbα-LB. If the particle conjugated only rGPIbα-LB or AMS (rigid particle) is better than vesicle (particle with deformability) from viewpoint of adhesion and concentration profile. But the mobility of rGPIbα-vesicle is bigger than rGPIbα-LB in blood flow. We must consider which carrier we employ based on those characteristics.

    DOI CiNii

  • 236 人工血小板の微視的運動の粘着に対する影響(OS1-13 : 生体マイクロ・ナノ新技術(2),マイクロ・ナノバイオメカニクス)

    藤田 英輝, 鈴木 健一, 緒方 亜美, 田村 典子, 後藤 信哉, 武岡 真司, 池田 康夫, 谷下 一夫

    バイオエンジニアリング学術講演会・セミナー講演論文集   2004   287 - 288  2005年

    DOI CiNii

  • Physiologic capacity of reticuloendothelial system for degradation of Hb-vesicles (artificial oxygen carriers) after massive intravenous doses by daily repeated infusions for 14 days

    Sakai, H., Sou, K., Takeoka, S., Horinouchi, H., Kobayashi, K., Tsuchida, E.

    Polymer Preprints, Japan   54 ( 1 )  2005年

  • Pharmacokinetics properties of surface-modified vesicles

    Sou, K., Coins, B., Phillips, W.T., Takeoka, S., Tsuchida, E.

    Polymer Preprints, Japan   54 ( 2 )  2005年

  • Ligand exchange of hemoglobin vesicle with the model device optimized its light response to gas-liquid boundary face more efficient

    Suzuki, D., Takeoka, S., Sou, K., Tsuchida, E.

    Polymer Preprints, Japan   54 ( 2 )  2005年

  • Circulatory half-life time of artificial red blood cell (hemoglobin-vesicles) and their distribution to metabolic organs

    Sou, K., Goins, B., Phillips, W.T., Sakai, H., Takeoka, S., Tsuchida, E.

    Polymer Preprints, Japan   54 ( 1 )  2005年

  • 人工血液

    堀之内 宏久, 相原 源就, 野上 弥志郎, 武岡 真司, 岡村 陽介

    人工臓器   34 ( 2 ) s102 - s104  2005年

    DOI CiNii

  • Hemoglobin-vesicles (HbV) as artificial oxygen carriers

    H Sakai, K Sou, S Takeoka, K Kobayashi, E Tsuchida

    ARTIFICIAL OXYGEN CARRIER: ITS FRONT LINE   12   135 - 168  2005年  [査読有り]

     概要を見る

    Considering the physiological significance of the cellular structure of a red blood cell (RBC), it may be reasonable to mimic its structure for designing a hemoglobin (Hb)-based oxygen carrier. In this chapter, we have summarized the characteristics and performances of Hb-vesicles (HbV) that have been developed on the basis of molecular assembly. Collaborative in vitro and in vivo studies have revealed sufficient safety and efficacy of HbV.

  • Oxygen Infusions (Hemoglobin-Vesicles and Albumin-Hemes) Based on Nano-Molecular Sciences

    E. Tsuchida, H. Sakai, T. Komatsu, S. Takeoka, Y. Huang, K. Sou, A. Nakagawa, Y. Teramura, K. Kobayashi

    Polymers Adv.   16   73-83  2005年

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  • Effects of hemoglobin vesicles on resting and agonist-stimulated human platelets in vitro

    S Wakamoto, M Fujihara, H Abe, M Yamaguchi, H Azuma, H Ikeda, S Takeoka, E Tsuchida

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND BIOTECHNOLOGY   33 ( 2 ) 101 - 111  2005年

     概要を見る

    Hemoglobin vesicles (HbV) are artificial oxygen carriers that encapsulate a concentrated hemoglobin (Hb) solution with a phospholipid bilayer membrane. The oxygen transporting ability of HbV in vivo has been demonstrated by the transfusion of HbV into hemorrhagic shock rodent models. However, the compatibility of HbV with human blood cells must be evaluated. Preincubation of platelets with concentrations of 20% or 40% HbV had no effect on the binding of PAC-1, a monoclonal antibody that detects activation-dependent conformational changes in alpha(IIb)beta(3) on platelets, or the surface expression of CD62P in whole blood. ADP-induced increases in PAC-1 binding were significantly enhanced by exposing the platelets to concentrations of either 20% or 40% HbV, whereas the ADP-induced increases in CD62P expression were not affected by HbV treatment at either concentration. Preincubation of platelet-rich plasma (PRP) with HbV minimally reduced the spontaneous release of TXB2 and RANTES, but did not significantly affect the formation of TXB2 or the release of RANTES and beta-TG in platelets stimulated with ADP. Similarly, preincubation of PRP with HbV minimally reduced the spontaneous release of RANTES but did not significantly affect the formation of TXB2 or the release of RANTES and beta-TG in platelets stimulated with collagen, although collagen-induced serotonin release tended to decrease with HbV pretreatment. These data suggest that the exposure of human platelets to high concentrations of HbV (up to 40%) in vitro did not cause platelet activation and did not adversely affect the formation and secretion of prothrombotic substances or proinflammatory substances triggered by platelet agonists, although one of the earliest events in ADP-induced platelet activation was slightly potentiated by HbV pretreatment at the doses tested. Taken together, these results imply that HbV, at concentrations of up to 40%, do not have any aberrant interactions with either unstimulated or agonist-induced platelets.

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  • Developmental Trend of Artificial Blood (Artificial Red Blood Cells)

    Takeoka, S

    JMAJ   48 ( 3 ) 1 - 5  2005年

  • Physiological capacity of the reticuloendothelial system for the degradation of hemoglobin vesicles (artificial oxygen carriers) after massive intravenous doses by daily repeated infusions for 14 days

    H Sakai, Y Masada, H Horinouchi, E Ikeda, K Sou, S Takeoka, M Suematsu, M Takaori, K Kobayashi, E Tsuchida

    JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS   311 ( 3 ) 874 - 884  2004年12月

     概要を見る

    A hemoglobin vesicle (HbV; diameter 252 +/- 53 nm) or liposome-encapsulated Hb is an artificial oxygen carrier developed for use as a transfusion alternative, and its oxygen-transporting capacity has been well characterized, although critical physiological compartments for the Hb degradation after a massive infusion of HbV and the safety outcome remain unknown. In this study, we aimed to examine the compartments for its degradation by daily repeated infusions (DRI) of HbV, focusing on its influence on the reticuloendothelial system ( RES). Male Wistar rats intravenously received the HbV suspension at 10 ml/kg/day for 14 consecutive days. The cumulative infusion volume ( 140 ml/kg) was equal to 2.5 times the whole blood volume ( 56 ml/kg). The animals tolerated the DRI well and survived, and body weights continuously increased. One day after DRI, hepatosplenomegaly occurred significantly through the accumulation of large amounts of HbV. Plasma clinical chemistry was overall normal, except for a transient elevation of lipid components derived from HbV. These symptoms subsided 14 days after DRI. Hemosiderin deposition and up-regulation of heme oxygenase-1 coincided in the liver and spleen but were not evident in the parenchyma of these organs. Furthermore, the plasma iron and bilirubin levels remained unchanged, suggesting that the heme-degrading capacity of the RES did not surpass the ability to eliminate bilirubin. In conclusion, phospholipid vesicles for the encapsulation of Hb would be beneficial for heme detoxification through their preferential delivery to the RES, a physiological compartment for degradation of senescent RBCs, even at doses greater than putative clinical doses.

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  • 血小板代替物の展開

    武岡真司, 岡村陽介

    Molecular Medicine   41 ( 12 ) 1494 - 1500  2004年12月

    CiNii

  • Physicochemical characterization of cross-linked human serum albumin dimer and its synthetic heme hybrid as an oxygen carrier.

    Teruyuki Komatsu, Yukiko Oguro, Yuji Teramura, Shinji Takeoka, Junpei Okai, Makoto Anraku, Masaki Otagiri, Eishun Tsuchida

    Biochimica et biophysica acta   1675 ( 1-3 ) 21 - 31  2004年11月  [国際誌]

     概要を見る

    The recombinant human serum albumin (rHSA) dimer, which was cross-linked by a thiol group of Cys-34 with 1,6-bis(maleimido)hexane, has been physicochemically characterized. Reduction of the inert mixed-disulfide of Cys-34 beforehand improved the efficiency of the cross-linking reaction. The purified dimer showed a double mass and absorption coefficient, but unaltered molar ellipticity, isoelectric point (pI: 4.8) and denaturing temperature (65 degrees C). The concentration dependence of the colloid osmotic pressure (COP) demonstrated that the 8.5 g dL(-1) dimer solution has the same COP with the physiological 5 g dL(-1) rHSA. The antigenic epitopes of the albumin units are preserved after bridging the Cys-34, and the circulation lifetime of the 125I-labeled variant in rat was 18 h. A total of 16 molecules of the tetrakis[(1-methylcyclohexanamido)phenyl]porphinatoiron(II) derivative (FecycP) is incorporated into the hydrophobic cavities of the HSA dimer, giving an albumin-heme hybrid in dimeric form. It can reversibly bind and release O2 under physiological conditions (37 degrees C, pH 7.3) like hemoglobin or myoglobin. Magnetic circular dichroism (CD) revealed the formation of an O2-adduct complex and laser flash photolysis experiments showed the three-component kinetics of the O2-recombination reaction. The O2-binding affinity and the O2-association and -dissociation rate constants of this synthetic hemoprotein have also been evaluated.

    PubMed

  • Physicochemical characterization of cross-linked human serum albumin dimer and its synthetic heme hybrid as an oxygen carrier

    T Komatsu, Y Oguro, Y Teramura, S Takeoka, J Okai, M Anraku, M Otagiri, E Tsuchida

    BIOCHIMICA ET BIOPHYSICA ACTA-GENERAL SUBJECTS   1675 ( 1-3 ) 21 - 31  2004年11月

     概要を見る

    The recombinant human serum albumin (rHSA) dimer, which was cross-linked by a thiol group of Cys-34 with 1,6-bis(maleimido)hexane, has been physicochemically characterized. Reduction of the inert mixed-disulfide of Cys-34 beforehand improved the efficiency of the cross-linking reaction. The purified dimer showed a double mass and absorption coefficient, but unaltered molar ellipticity, isoelectric point (pl: 4.8) and denaturing temperature (65degreesC). The concentration dependence of the colloid osmotic pressure (COP) demonstrated that the 8.5 g dL(-1) dimer solution has the same COP with the physiological 5 g dL(-1) rHSA. The antigenic epitopes of the albumin units are preserved after bridging the Cys-34, and the circulation lifetime of the I-125-labeled variant in rat was 18 h. A total of 16 molecules of the tetrakis{(1-methylcyclohexanamido)phenyl}porphinatoiron(II) derivative (FecycP) is incorporated into the hydrophobic cavities of the HSA dimer, giving an albumin-heme hybrid in dimeric form. It can reversibly bind and release O-2 under physiological conditions (37degreesC, pH 7.3) like hemoglobin or myoglobin. Magnetic circular dichroism (CD) revealed the formation of an O-2-adduct complex and laser flash photolysis experiments showed the three-component kinetics of the O-2-recombination reaction. The O-2-binding affinity and the O-2-association and -dissociation rate constants of this synthetic hemoprotein have also been evaluated. (C) 2004 Elsevier B.V. All rights reserved.

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  • 3-Dithiolthione-substituted polythiophene and its redox activities

    Takemura, I, T Iwasaki, S Takeoka, H Nishide

    CHEMISTRY LETTERS   33 ( 11 ) 1482 - 1483  2004年11月

     概要を見る

    We synthesized 3-dithiolthione-substituted polythiophene, poly [3-(1',2-dithiol-3'-thione-4'-yl)thiophene], by cyclization reaction of poly [3-bis(methoxycaronyl)methyl thiophene]. Its redox behavior and electronic states showed that the oxidation of the polythiophene followed the oxidation of the dithiolthione ring to the radical cation of the dithiolthione ring.

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  • Recognition Properties of Polymerized Albumin Particles and Phospholipid Vesicles Bearing Recognition Proteins

    S. Takeoka, Y. Okamura, Y. Teramura, E. Tsuchida, Y. Okamura, Y. Teramura, E. Tsuchida, M. Handa, Y. Y. Teramura, E. Tsuchida, M. Handa, Y. Ikeda

    Japan-UK Platelet Conference, Oxford UK   Abstract   26  2004年09月

  • Reduction of methemoglobin via electron transfer from photoreduced flavin: Restoration of O-2-binding of concentrated hemoglobin solution coencapsulated in phospholipid vesicles

    H Sakai, Y Masada, H Onuma, S Takeoka, E Tsuchida

    BIOCONJUGATE CHEMISTRY   15 ( 5 ) 1037 - 1045  2004年09月

     概要を見る

    Ferric methemoglobin is reduced to its ferrous form by photoirradiation either by direct photoexcitation of the heme portion to induce electron transfer from the surrounding media (Sakai at al. (2000) Biochemistry 39, 14595-14602) or by an indirect electron transfer from a photochemically reduced electron mediator such as flavin. In this research, we studied the mechanism and optimal condition that facilitates photoreduction of flavin mononucleotide (FMN) to FMNH2 by irradiation of visible light, and the succeeding reduction of concentrated metHb in phospholipid vesicles to restore its 02 binding ability. Visible light irradiation (435 nm) of a metHb solution containing FMN and an electron donor such as EDTA showed a significantly fast reduction to ferrous Hb with a quantum yield (Phi) of 0.17, that is higher than the method of direct photoexcitation of heme ( Phi = 0.006). Electron transfer from a donor molecule to metHb via FMN was completed within 30 ns. Native-PAGE and IEF electrophoresis indicated no chemical modification of the surface of the reduced Hb. Coencapsulation of concentrated Hb solution (35 g/dL) and the FMN/EDTA system in vesicles covered with a phospholipid bilayer membrane (Hb-vesicles, HbV, diameter: 250 nm) facilitated the metHb photoreduction even under aerobic conditions, and the reduced HbV restored the reversible O-2 binding property. A concentrated HbV suspension ([Hb] = 8 g/dL) was sandwiched with two glass plates to form a liquid layer with the thickness of about 10 mum (close to capillary diameter in tissue, 5 mum), and visible light irradiation (221 mW/cm(2)) completed 100% metHb photoreduction within 20 s. The photoreduced FMNH2 reacted with O-2 to produce H2O2, which was detected by the fluorescence measurement of the reaction of H2O2 and p-nitrophenylacetic acid. However, the amount of H2O2 generated during the photoreduction of HbV was significantly reduced in comparison with the homogeneous Hb solution, indicating that the photoreduced FMNH2 was effectively consumed during the metHb reduction in a highly concentrated condition inside the HbV nanoparticles.

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  • Hemorrhagic shock resuscitation with an artificial oxygen carrier, hemoglobin vesicle, maintains intestinal perfusion and suppresses the increase in plasma tumor necrosis factor-alpha

    A Yoshizu, Y Izumi, S Park, H Sakai, S Takeoka, H Horinouchi, E Ikeda, E Tsuchida, K Kobayashi

    ASAIO JOURNAL   50 ( 5 ) 458 - 463  2004年09月

     概要を見る

    It is known that damage to the intestinal mucosa followed by systemic inflammatory response is one of the leading causes of shock related morbidity and mortality. In this study, we examined the ability of an artificial oxygen carrier hemoglobin vesicle (HbV) to sustain systemic and intestinal perfusion during hemorrhagic shock. In rabbits, hemorrhagic shock (40% of the estimated blood volume) was resuscitated with 5% albumin (alb group), HbV suspended in 5% albumin (HbValb group), or washed red blood cells suspended in 5% albumin (RBCalb group). Plasma tumor necrosis factor (TNF)-alpha level was measured in rats under the same experimental protocol. No significant intergroup differences were seen in systemic hemodynamics. In contrast, parameters of intestinal perfusion significantly deteriorated in the alb group but were equally well sustained in the HbValb and RBCalb groups. Also, a significant increase in plasma TNF-alpha level was seen in the alb group but not in the RBCalb or HbValb groups. These results indicate the proficient oxygen transporting capability of HbV and its potential efficacy in shock resuscitation.

    DOI

  • Metabolism of hemoglobin-vesicles (artificial oxygen carriers) and their influence on organ functions in a rat model

    H Sakai, H Horinouchi, Y Masada, S Takeoka, E Ikeda, M Takaori, K Kobayashi, E Tsuchida

    BIOMATERIALS   25 ( 18 ) 4317 - 4325  2004年08月

     概要を見る

    Phospholipid vesicles encapsulating Hb (Hb-vesicies: HbV) have been developed for use as artificial O-2 carriers (250 nm phi). As one of the safety evaluations, we analyzed the influence of HbV on the organ functions by laboratory tests of plasma on a total of 29 analytes. The HbV Suspension ([Hb] = 10 g/dl) was intravenously infused into male Wistar rats (20 ml/kg; whole blood = 56 ml/kg). The blood was withdrawn at 8 h, and 1, 2, 3, and 7 days after infusion, and the plasma was ultracentrifuged to remove HbV in order to avoid its interference effect oil the analytes. Enzyme concentrations, AST, ALT, ALP, and LAP showed significant, but minor changes. and did not show a sign of a deteriorative damage to the liver that was one of the main organs for the HbV entrapment and the succeeding metabolism. The amylase and lipase activities showed reversible changes, however, there was no morphological changes in pancreas. Plasma bilirubin and iron did not increase in spite of the fact that a large amount of Hb was metabolized in the macrophages. Cholesterols, phospholipids, and beta-lipoprotein transiently increased showing the maximum at 1 or 2 days, and returned to the control level at 7 days. They should be derived from the membrane components of HbV that are liberated from macrophages entrapping HbV. Together with the previous report of the prompt metabolism of HbV in the reticuloendothelial system by histopathological examination, it can be concluded that HbV infusion transiently modified the values of the analytes without any; irreversible damage to the corresponding organs at the bolus infusion rate of 20 ml/kg. (C) 2003 Elsevier Ltd. All rights reserved.

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  • Recognition properties of platelet membrane protein (rGPIb alpha)-conjugated particles made of polymerized albumin and phospholipids under flow conditions.

    S Takeoka, E Tsuchida, Y Ikeda

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   227   U348 - U348  2004年03月

  • Detection of lipopolysaccharide in hemoglobin-vesicles by Limulus amebocyte lysate test with kinetic-turbidimetric gel clotting analysis and pretreatment of surfactant

    H Sakai, S Hisamoto, Fukutomi, I, K Sou, S Takeoka, E Tsuchida

    JOURNAL OF PHARMACEUTICAL SCIENCES   93 ( 2 ) 310 - 321  2004年02月

     概要を見る

    A method to quantitatively measure the bacterial endotoxin content (lipopolysaccharide, LPS) in phospholipid vesicles or liposomes is necessary because the conventional Limulus amebocyte lysate (LA-L) test does not provide an accurate measurement due to the hydrophobic interaction of LPS and vesicles that shields the activity of LPS to clot the LA-L coagulant. This interference was evident from isothermal titration calorimetry results in our study that clearly demonstrated the insertion of the LPS molecule into the phospholipid bilayer membrane. Hemoglobin-vesicles (HbVs; particle diameter = 251+/-80 nm; [Hb] = 10 g/dL) are artificial oxygen carriers encapsulating a conc. Hb solution in phospholipid vesicles, and their oxygen transporting ability has been extensively studied. To accurately measure the LPS content in the HbV suspension, we tested the solubilization of HbV with deca(oxyethylene) dodecyl ether (C12E10), used to release the LPS entrapped in the vesicles, as a pretreatment for the succeeding LAL assay of the kinetic-turbidimetric gel clotting (detecting wavelength, 660 nm). The C12E10 surfactant interferes with the gel clotting in a concentration-dependent manner, and the optimal condition was determined in terms of minimizing the dilution factor and C12E10 concentration. We clarified the condition that allowed the measurement of LPS at &gt; 0.1 endotoxin units (EU)/mL in the HbV suspension. Moreover, the utilization of histidine-immobilized agarose gel effectively concentrated the trace amount of LPS from the C12E10-solubilized HbV solution and washed out C12E10 as an inhibitory element. The LA-L assay with the LPS-adsorbed gel resulted in the detection limit of 0.0025 EU/mL. Pretreatment with C12E10 would be applicable not only to HbVs but also to other drug delivery systems using phospholipid vesicles encapsulating or incorporating functional molecules. (C) 2004 Wiley-Liss, Inc.

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  • Hemoglobin-vesicles suspended in recombinant human serum albumin for resuscitation from hemorrhagic shock in anesthetized rats

    H Sakai, Y Masada, H Horinouchi, M Yamamoto, E Ikeda, S Takeoka, K Kobayashi, E Tsuchida

    CRITICAL CARE MEDICINE   32 ( 2 ) 539 - 545  2004年02月

     概要を見る

    Objective: Hemoglobin-vesicle (HbV) has been developed to provide oxygen-carrying ability to plasma expanders. Its ability to restore the systemic condition after hemorrhagic shock was evaluated in anesthetized Wistar rats for 6 hrs after resuscitation. The HbV was suspended in 5 g/dL recombinant human serum albumin (HbV/rHSA) at an Hb concentration of 8.6 g/dL.
    Design: Prospective, randomized, controlled trial.
    Setting: Department of Surgery, School of Medicine, Keio University.
    Subjects: Forty male Wistar rats.
    Interventions: The rats were anesthetized with 1.5% sevoflurane inhalation throughout the experiment. Polyethylene catheters were introduced through the right jugular vein into the right atrium for infusion and into the right common carotid artery for blood withdrawal and mean arterial pressure monitoring.
    Measurements and Main Results: Shock was induced by 50% blood withdrawal. The rats showed hypotension (mean arterial pressure = 32 +/- 10 mm Hg) and significant metabolic acidosis and hyperventilation. After 15 mins, they received HbV/rHSA, shed autologous blood (SAB), washed homologous red blood cells (wRBC) suspended in rHSA (wRBC/rHSA, [Hb] = 8.6 g/dL), or rHSA alone. The HbV/rHSA group restored mean arterial pressure to 93 +/- 8 mm Hg at 1 hr, similar to the SAB group (92 +/- 9 mm Hg), which was significantly higher compared with the rHSA (74 9 mm Hg) and wRBC/rHSA (79 8 mm Hg) groups. There was no remarkable difference in the blood gas variables between the resuscitated groups; however, two of eight rats in the rHSA group died before 6 hrs. After 6 hrs, the rHSA group showed significant ischemic changes in the right cerebral hemisphere relating to the ligation of the right carotid artery followed by cannulation, whereas the HbV/rHSA, SAB, and wRBC/rHSA groups showed less changes.
    Conclusions: HbV suspended in recombinant human serum albumin provides restoration from hemorrhagic shock that is comparable with that using shed autologous blood.

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  • 人工血液14題

    寺岡 慧, 武岡 真司, 織田 禎二, 酒井 宏水, 岡村 陽介

    人工臓器   33 ( 2 ) s183 - s184  2004年

    DOI CiNii

  • Stability of porphyrin-calix[4]arene complexes analyzed by electrospray ionization mass spectrometry

    S Arai, S Ishihara, S Takeoka, H Ohkawa, T Shibue, H Nishide

    RAPID COMMUNICATIONS IN MASS SPECTROMETRY   18 ( 18 ) 2065 - 2068  2004年

     概要を見る

    The stability of some porphyrin-calix[4]arene sodium-ion complexes were determined by a collision-activated decomposition (CAD) method utilizing electrospray ionization mass spectrometry (ESI-MS). Comparing the values of E-1/2, the collision energy at which the relative intensity of the complex ion is 0.5, we found that the porphyrin-calix[4]arene complex with the higher value of E-1/2 corresponded to that with the larger association constant (K-ass), as measured by H-1-NMR in CDCl3. Both our ESI-MS and NMR studies proved that the number of hydrogen bonds and the rigidity of the calix[4]arene stabilized the complex. The ESI-MS technique could be successful in screening the binding affinity in host-guest systems with a small amount of sample. Copyright (C) 2004 John Wiley Sons, Ltd.

    DOI

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    14
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  • 血小板代替物の担体設計からDrug Local Deliveryの可能性

    武岡真司, 岡村陽介, 土田英俊, 池田康夫

    日本血栓止血学会誌   15 ( 1 ) 21 - 26  2004年

    DOI CiNii

  • 話題の焦点、実用化に近づく人工赤血球(人工酸素運搬体),

    武岡真司

    アニムス   34   34 - 38  2004年

  • 輸血の有効性と安全性−血液新法施行下での輸血医療の方向,輸血医療のトピックス,人工血液(人工赤血球)の開発動向,

    武岡真司

    日本医師会雑誌   131   907 - 909  2004年

  • 止血機能を有する微粒子系の設計と機能評価

    武岡真司, 岡村陽介

    Cardiovascular Anesthesia   8   35 - 42  2004年

  • [Safety of artificial oxygen carrier (synthetic erythrocytes) and the ability to supply oxygen to tissues].

    Eidetoshi Tsuchida, Keitaro Sou, Hiromizu Sakai, Kirayuki Komatsu, Shinji Takeoka, Hirohisa Horinouchi, Makoto Suematsu, Koichi Kobayashi

    Masui. The Japanese journal of anesthesiology   52 Suppl   S55-66  2003年12月  [国内誌]

    PubMed

  • Function of fibrinogen gamma-chain dodecapeptide-conjugated latex beads under flow

    S Takeoka, Y Okamura, Y Teramura, N Watanabe, H Suzuki, E Tsuchida, M Handa, Y Ikeda

    BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS   312 ( 3 ) 773 - 779  2003年12月

     概要を見る

    In order to perform a fundamental study of platelet substitutes, novel particles that bound to activated platelets were prepared using two oligopeptides conjugated to latex beads. The oligopeptides were CHHLGGAKQAGDV (H12), which is a fibrinogen gamma-chain carboxy-terminal sequence (gamma 400-411), and CGGRGDF (RGD), which contains a fibrinogen alpha-chain sequence (alpha 95-98 RGDF). Both peptides contained an additional amino-terminal cysteine to enable conjugation. Human serum albumin was adsorbed onto the surface of latex beads (average diameter 1 mum) and pyridyldisulfide groups were chemically introduced into the adsorbed protein. H 12 or RGD peptides were then chemically linked to the modified surface protein via disulfide linkages. H12- or RGD-conjugated latex beads prepared in this way enhanced the in vitro thrombus formation of activated platelets on collagen-immobilized plates under flowing thrombocytopenic-imitation blood. Based on the result of flow cytometric analyses of agglutination, PAG-1 binding, antiP-selectin antibody binding, and annexin V binding, the H12-conjugated latex beads showed minimal interaction with non-activated platelets. These results indicate the excellent potential of H12-conjugated particles as a candidate for a platelet substitute. (C) 2003 Elsevier Inc. All rights reserved.

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    33
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  • O-2 release from Hb vesicles evaluated using an artificial, narrow O-2-permeable tube: comparison with RBCs and acellular Hbs

    H Sakai, Y Suzuki, M Kinoshita, S Takeoka, N Maeda, E Tsuchida

    AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY   285 ( 6 ) H2543 - H2551  2003年12月

     概要を見る

    A phospholipid vesicle that encapsulates a concentrated hemoglobin (Hb) solution and pyridoxal 5'-phosphate as an allosteric effector [ Hb vesicle (HbV) diameter, 250 nm] has been developed to provide an O-2 carrying ability to plasma expanders. The O-2 release from flowing HbVs was examined using an O-2-permeable, fluorinated ethylenepropylene copolymer tube (inner diameter, 28 mum) exposed to a deoxygenated environment. Measurement of O-2 release was performed using an apparatus that consisted of an inverted microscope and a scanning-grating spectrophotometer with a photon-count detector, and the rate of O-2 release was determined based on the visible absorption spectrum in the Q band of Hb. HbVs and fresh human red blood cells (RBCs) were mixed in various volume ratios at a Hb concentration of 10 g/dl in isotonic saline that contained 5 g/dl albumin, and the suspension was perfused at the centerline flow velocity of 1 mm/s through the narrow tube. The mixtures of acellular Hb solution and RBCs were also tested. Because HbVs were homogeneously dispersed in the albumin solution, increasing the volume of the HbV suspension resulted in a thicker marginal RBC-free layer. Irrespective of the mixing ratio, the rate of O-2 release from the HbV/RBC mixtures was similar to that of RBCs alone. On the other hand, the addition of 50 vol% of acellular Hb solution to RBCs significantly enhanced the rate of deoxygenation. This outstanding difference in the rate of O-2 release between the HbV suspension and the acellular Hb solution should mainly be due to the difference in the particle size ( 250 vs. 7 nm) that affects their diffusion for the facilitated O-2 transport.

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  • Prolonged oxygen-carrying ability of hemoglobin vesicles by coencapsulation of catalase in vivo

    Y Teramura, H Kanazawa, H Sakai, S Takeoka, E Tsuchida

    BIOCONJUGATE CHEMISTRY   14 ( 6 ) 1171 - 1176  2003年11月

     概要を見る

    Hemoglobin (Hb) vesicles (particle diameter, ca. 250 nm) have been developed as Hb-based oxygen carriers in which a purified Hb solution is encapsulated with a phospholipid bilayer membrane. The oxidation of Hb to nonfunctional ferric Hb (metHb) was caused by reactive oxygen species, especially hydrogen peroxide (H2O2), in vivo in addition to autoxidation. We focused on the enzymatic elimination of H2O2 to suppress the metHb formation in the Hb vesicles. In this study, we coencapsulated catalase with Hb within vesicles and studied the rate of metHb formation in vivo. The Hb vesicles containing 5.6 x 10(4) unit mL(-1) catalase decreased the rate of metHb formation by half in comparison with Hb vesicles without catalase. We succeeded in prolonging the oxygen-carrying ability of the Hb vesicle in vivo by the coencapsulation of catalase.

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    34
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  • A duplex of tetra(2-pyridyl)porphyrin and tetrahydroxylcalix[4]arene

    H Ohkawa, S Arai, S Takeoka, T Shibue, H Nishide

    CHEMISTRY LETTERS   32 ( 11 ) 1052 - 1053  2003年11月

     概要を見る

    meso-Tetra(2-pyridyl)porphyrin forms a duplex with tetrahydroxylealix[4]arene via triplicate or quadruple hydrogen bonds, to provide a capping structure on the porphyrin plane.

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    15
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  • 代謝系人工臓器・人工酸素運搬体のニューテクノロジー 人工赤血球 その機能,生体反応,安全性について

    堀之内 宏久, 小林 紘一, 渡辺 真純, 泉 陽太郎, 山内 徳子, 山本 学, 末松 誠, 武岡 真司, 酒井 宏水, 小松 晃之, 土田 英俊

    人工臓器   32 ( 2 ) S22 - S22  2003年09月

  • Effective encapsulation of proteins into size-controlled phospholipid vesicles using freeze-thawing and extrusion

    K Sou, Y Naito, T Endo, S Takeoka, E Tsuchida

    BIOTECHNOLOGY PROGRESS   19 ( 5 ) 1547 - 1552  2003年09月

     概要を見る

    We are aiming to improve the encapsulation efficiency of proteins in a size-regulated phospholipid vesicle using an extrusion method. Mixed lipids (1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC), cholesterol, 1,5-dipalmitoyl-L-glutamate-N-succinic acid (DPEA), and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[monomethoxy poly(ethylene glycol) (5,000)] (PEG-DSPE) at a molar ratio of 5, 5, 1, and 0.033 were hydrated with a NaOH solution (7.6 mM) to obtain a polydispersed multilamellar vesicle dispersion (50 nm to 30 mum diameter). The polydispersed vesicles were converted to smaller vesicles having an average diameter of ca. 500 nm with a relatively narrow size distribution by freeze-thawing at a lipid concentration of 2 g dL(-1) and cooling rate of -140 degreesC min(-1). The lyophilized powder of the freeze-thawed vesicles was rehydrated into a concentrated protein solution (carbonyl hemoglobin solution, 40 g dL(-1)) and retained the size and size distribution of the original vesicles. The resulting vesicle dispersion smoothly permeated through the membrane filters during extrusion. The average permeation rate of the freeze-thawed vesicles was ca. 30 times faster than that of simple hydrated vesicles. During the extrusion process, proteins were encapsulated into the reconstructed vesicles with a diameter of 250 20 nm.

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  • Effective encapsulation of proteins into size-controlled phospholipid vesicles using freeze-thawing and extrusion

    K Sou, Y Naito, T Endo, S Takeoka, E Tsuchida

    BIOTECHNOLOGY PROGRESS   19 ( 5 ) 1547 - 1552  2003年09月

     概要を見る

    We are aiming to improve the encapsulation efficiency of proteins in a size-regulated phospholipid vesicle using an extrusion method. Mixed lipids (1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC), cholesterol, 1,5-dipalmitoyl-L-glutamate-N-succinic acid (DPEA), and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[monomethoxy poly(ethylene glycol) (5,000)] (PEG-DSPE) at a molar ratio of 5, 5, 1, and 0.033 were hydrated with a NaOH solution (7.6 mM) to obtain a polydispersed multilamellar vesicle dispersion (50 nm to 30 mum diameter). The polydispersed vesicles were converted to smaller vesicles having an average diameter of ca. 500 nm with a relatively narrow size distribution by freeze-thawing at a lipid concentration of 2 g dL(-1) and cooling rate of -140 degreesC min(-1). The lyophilized powder of the freeze-thawed vesicles was rehydrated into a concentrated protein solution (carbonyl hemoglobin solution, 40 g dL(-1)) and retained the size and size distribution of the original vesicles. The resulting vesicle dispersion smoothly permeated through the membrane filters during extrusion. The average permeation rate of the freeze-thawed vesicles was ca. 30 times faster than that of simple hydrated vesicles. During the extrusion process, proteins were encapsulated into the reconstructed vesicles with a diameter of 250 20 nm.

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  • Improved oxygenation in ischemic hamster flap tissue is correlated with increasing hemodilution with Hb vesicles and their O-2 affinity

    C Contaldo, S Schramm, R Wettstein, H Sakai, S Takeoka, E Tsuchida, M Leunig, A Banic, D Erni

    AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY   285 ( 3 ) H1140 - H1147  2003年09月

     概要を見る

    The aim of this study was to test the influence of oxygen affinity of Hb vesicles (HbVs) and level of blood exchange on the oxygenation in collateralized, ischemic, and hypoxic hamster flap tissue during normovolemic hemodilution. Microhemodynamics were investigated with intravital microscopy. Tissue PO2 was measured with Clarktype microprobes. HbVs with a P-50 of 15 mmHg (HbV15) and 30 mmHg (HbV30) were suspended in 6% Dextran 70 (Dx70). The Hb concentration of the solutions was 7.5 g/dl. A stepwise replacement of 15%, 30%, and 50% of total blood volume was performed, which resulted in a gradual decrease in total Hb concentration. In the ischemic tissue, hemodilution led to an increase in microvascular blood flow to maximally 141 +/- 166% of baseline in all groups ( median; P &lt; 0.01 vs. baseline, not significant between groups). Oxygen tension was transiently raised to 121 +/- 17% after the 30% blood exchange with Dx70 ( P &lt; 0.05), whereas it was increased after each step of hemodilution with HbV15-Dx70 and HbV30-Dx70, reaching 217 +/- 67% ( P &lt; 0.01) and 164 +/- 33% ( P &lt; 0.01 vs. baseline and other groups), respectively, after the 50% blood exchange. We conclude that despite a decrease in total Hb concentration, the oxygenation in the ischemic, hypoxic tissue could be improved with increasing blood exchange with HbV solutions. Furthermore, better oxygenation was obtained with the left-shifted HbVs.

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  • Hemostatic effects of polymerized albumin particles bearing rGPIa/IIa in thrombocytopenic mice

    Y Teramura, Y Okamura, S Takeoka, H Tsuchiyama, H Narumi, M Kainoh, M Handa, Y Ikeda, E Tsuchida

    BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS   306 ( 1 ) 256 - 260  2003年06月

     概要を見る

    The recombinant fragment of the platelet membrane glycoprotein Ia/IIa (rGPIa/IIa) was conjugated to the polymerized albumin particles (polyAlb) with the average diameter of 180 nm. The intravenous administration of rGPIa/IIa polyAlb to thrombocytopenic mice ([platelet] = 2.1 +/- 0.3 x 10(5) particles/muL) with three doses of ca. 2.4 x 10(10), 7.2 x 10(10), and 2.4 x 10(11) particles/kg, respectively, significantly reduced their bleeding time to 426 +/- 71, 378 +/- 101, and 337 +/- 46 s, respectively, whereas that of the control groups (PBS) was 730 +/- 198 s. The injection of rGPIa/IIa-polyAlb (2.4 x 10(11) particles/kg) was approximately equal to the effect of the injection of the mouse platelets at a dose of 2.0 x 10(10) particles/kg. It was confirmed that rGPIa/IIa-polyAlb had a recognition ability against collagen and could contribute to the hemostasis in the thrombocytopenic mice as a platelet, substitute. (C) 2003 Elsevier Science (USA). All rights reserved.

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    22
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  • Normovolemic hemodilution with Hb vesicle solution attenuates hypoxia in ischemic hamster flap tissue

    D Erni, R Wettstein, S Schramm, C Contaldo, H Sakai, S Takeoka, E Tsuchida, M Leunig, A Banic

    AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY   284 ( 5 ) H1702 - H1709  2003年05月

     概要を見る

    The aim of this study was to test whether oxygenation in acutely ischemic, collateralized tissue may be improved by normovolemic hemodilution with a solution containing liposome-encapsulated human Hb (HbV). A skin flap model in anesthetized hamsters was used, which consisted of two parts receiving either anatomic or collateral perfusion. Microhemodynamics were investigated with intravital microscopy. Partial tissue oxygen tension was measured with a Clark-type microprobe. Hemodilution was obtained by exchanging 50% of the total blood volume with HbV suspended in 8% human serum albumin (HSA8) or 6% Dextran 70 (Dx70). The size of the vesicles was 276 nm, the P-50 was 22 mmHg, and the Hb concentration of the solutions was 7.5 g/dl. Colloid osmotic pressure and viscosity were 49.9 mmHg and 8.7 cP for HbV-Dx70 and 40.0 mmHg and 2.9 cP for HbV-HSA8, respectively. Hemodilution with HbV-Dx70 led to an increase in microvascular blood flow in the ischemic microvessels to maximally 158% (median, P &lt; 0.01), whereas blood flow remained virtually unchanged after hemodilution with HbV-HSA8. In the ischemic tissue, oxygen tension was improved from 11.9 to 17.0 mmHg (P &lt; 0.01) after hemodilution with HbV-Dx70 but remained virtually unchanged after hemodilution with HbV-HSA8. Our study suggests that the oxygenation in acutely ischemic, collateralized tissue may be improved by normovolemic hemodilution with HbV suspended in Dx70. The effect was achieved by an increase in microcirculatory blood flow related to the rheological properties of the suspending medium.

    DOI

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    26
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  • Hemoglobin-vesicles as oxygen carriers: Influence on phagocytic activity and histopathological changes in reticuloendothelial system

    H. Horinouchi, K. Kobayashi, H. Sakai, K. Tomiyama, S. Takeoka, E. Tsuchida, E. Ikeda

    Keio Journal of Medicine   52   44 - 49  2003年  [査読有り]

    DOI

    Scopus

  • Pretreatment of serum containing hemoglobin vesicles (oxygen carriers) to prevent their interference in laboratory tests

    H Sakai, K Tomiyama, Y Masada, S Takeoka, H Horinouchi, K Kobayashi, E Tsuchida

    CLINICAL CHEMISTRY AND LABORATORY MEDICINE   41 ( 2 ) 222 - 231  2003年

     概要を見る

    Hemoglobin vesicles (HbV, diameter: 251+/-81 nm) are artificial oxygen (O-2) carriers encapsulating concentrated hemoglobin (Hb) solution with phospholipid bilayer membrane, and their O-2 transporting ability in vivo has been extensively studied. It is important to clarify the interference of the HbV suspension in clinical laboratory tests performed on serum and to establish a pretreatment method to avoid such an interference. The HbV suspension, acellular Hb solution ([Hb] = 10 g/dl) or saline, was mixed with a pooled human serum at various ratios up to 50 vol% ([Hb] = 5 g/dl), and the magnitude of the interference effect of HbV and Hb on 30 analytes was studied. The mixture of the HbV suspension and serum was ultracentrifuged (50000 g, 20 min) to remove the HbV particles as precipitate, and the supernatant was analyzed and compared with the saline control group. The HbV particles were also removed by centrifugation (2700 g, 30 min) in the presence of dextran (Mw 200 kDa). The HbV suspension showed considerable interference effects in most analytes. The majority of these effects was more serious than those of the acellular Hb solution. These findings are thought to be due to the light absorption of Hb in HbV and/or the light scattering generated in the suspension that interferes with the colorimetric and turbidimetric measurements. The components of HbV may also interfere with the chemical reactions of the studied assays. However, removal of the HbV from the supernatant diminished the interference in most of the assays: this is an advantage of HbV in comparison with acellular chemically modified Hb solutions.

    DOI

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    44
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  • DDSの基礎技術:キャリア ③リポソーム

    武岡真司, 寺村裕治, 池田康夫, 土田英俊

    血液・免疫・腫瘍   8 ( 2 ) 30 - 35  2003年

    J-GLOBAL

  • 酸素輸液(人工赤血球)の安全度と体組織への酸素供給

    土田英俊, 宗慶太郎, 酒井宏水, 小松晃之, 武岡真司, 堀之内宏久, 末松誠, 小林紘一

    麻酔   53 ( 増刊 ) s55 - 56  2003年

  • フィブリノーゲンγ鎖ドデカペプチド結合粒子の血小板代替物の展開

    岡村陽介, 寺村裕治, 武岡真司, 土田英俊, 鈴木英紀, 渡辺直英, 半田 誠, 池田康夫

    人工血液   11 ( 4 ) 205 - 210  2003年

    J-GLOBAL

  • 酸素輸液ヘモグロビン小胞体に混在するリポポリサッカライドの定量法

    久本秀治, 酒井宏水, 福富一平, 宗慶太郎, 武岡真司, 土田英俊

    人工血液   11 ( 3 ) 173 - 178  2003年

     概要を見る

    ヘモグロビン(Hb)を濃度高くリン脂質小胞体の内水相に内包したヘモグロビン小胞体(HbV)が人工酸素運搬体として開発され,赤血球と同等の酸素運搬機能と安全性が動物投与試験から明らかにされた.界面活性剤deca(oxyethylene)dodecyl ether(C12E10))でHbVを溶解してリポポリサッカライド(LPS)を遊離させた後,リムルステスト試薬と混合し,ゲル化反応を比濁時間分析法によって解析する方法を検討した.0.1EU/mLまでの検出限界を得ることができ,添加回収法によりその妥当性を検証することができた

  • 酸素輸液(人工赤血球)

    土田英俊, 酒井宏水, 武岡真司, 宗慶太郎, 小林紘一

    医学のあゆみ   205 ( 9 ) 558 - 566  2003年

  • Effect of Hb-encapsulation with vesicles on H2O2 reaction and lipid peroxidation

    S Takeoka, Y Teramura, T Atoji, E Tsuchida

    BIOCONJUGATE CHEMISTRY   13 ( 6 ) 1302 - 1308  2002年11月

     概要を見る

    We encapsulated a purified and concentrated hemoglobin (Hb) solution with a phospholipid bilayer membrane to form Hb vesicles (particle diameter, ca. 250 nm) for the development of artificial oxygen carriers. Reaction of Hb inside the vesicle with hydrogen peroxide (H2O2) is one of the important safety issues to be clarified and compared with a free Hb solution. During the reaction of the Hb solution with H2O2, metHb (Fe-III) and ferrylHb (Fe-IV=O) are produced, and H2O2 is decomposed by the catalase-like reaction of Hb. The aggregation of discolored Hb products due to heme degradation is accompanied by the release of iron (ferric ion). On the other hand, the concentrated Hb within the Hb vesicle reacts with H2O2 that permeated through the bilayer membrane, and the same products as the Hb solution are formed inside the vesicle. However, there is no turbidity change, no particle diameter change of the Hb vesicles, and no peroxidation of lipids comprising the vesicles after the reaction with H2O2. Furthermore, no free iron is detected outside the vesicle, though ferric ion is released from the denatured Hb inside the vesicle, indicating the barrier effect of the bilayer membrane against the permeation of ferric ion. When vesicles composed of egg york lecithin (EYL) as unsaturated lipids are added to the mixture of Hb and H2O2, the lipid peroxidation is caused by ferrylHb and hydroxyl radical generated from reaction of the ferric iron with H2O2, whereas no lipid peroxidation is observed in the case of the Hb vesicle dispersion because the saturated lipid membrane of the Hb vesicle should prevent the interaction of the ferrylHb or ferric iron with the EYL.

    DOI

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  • Systemic and microvascular responses to hemorrhagic shock and resuscitation with Hb vesicles

    H Sakai, S Takeoka, R Wettstein, AG Tsai, M Intaglietta, E Tsuchida

    AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY   283 ( 3 ) H1191 - H1199  2002年09月

     概要を見る

    A phospholipid vesicle encapsulating hemoglobin (Hb vesicle, HbV) has been developed to provide O-2-carrying capacity to plasma expanders. Its ability to restore systemic and microcirculatory conditions after hemorrhagic shock was evaluated in the dorsal skinfold window preparation of conscious hamsters. The HbV was suspended in 8% human serum albumin (HSA) at Hb concentrations of 3.8 g/dl [HbV(3.8)/HSA] and 7.6 g/dl [HbV(7.6)/HSA]. Shock was induced by 50% blood withdrawal, and mean arterial pressure (MAP) at 40 mmHg was maintained for 1 h by the additional blood withdrawal. The hamsters receiving either HbV(3.8)/HSA or HbV(7.6)/HSA suspensions restored MAP to 93+/-14 and 93+/-10 mmHg, respectively, similar with those receiving the shed blood (98+/-13 mmHg), which were significantly higher by comparison with resuscitation with HSA alone (62+/-12 mmHg). Only the HSA group tended to maintain hyperventilation and negative base excess after the resuscitation. Subcutaneous microvascular blood flow reduced to similar to10-20% of baseline during shock, and reinfusion of shed blood restored blood flow to similar to60-80% of baseline, an effect primarily due to the sustained constriction of small arteries A(0) (diameter 143+/-29 mum). The HbV(3.8)/HSA group had significantly better microvascular blood flow recovery and nonsignificantly better tissue oxygenation than of the HSA group. The recovery of base excess and improved tissue oxygenation appears to be primarily due to the increased oxygen-carrying capacity of HbV fluid resuscitation.

    DOI

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  • リコンビナントGPIbα結合担体としてのアルブミン重合体とリン脂質小胞体の機能比較

    岡村 陽介, 寺村 裕治, 武岡 真司, 土田 英俊, 半田 誠, 池田 康夫

    人工血液   10 ( 3 ) 92 - 92  2002年08月

  • Rolling properties of rGPIb alpha-conjugated phospholipid vesicles with different membrane flexibilities on vWf surface under flow conditions

    S Takeoka, Y Teramura, Y Okamura, E Tsuchida, M Handa, Y Ikeda

    BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS   296 ( 3 ) 765 - 770  2002年08月

     概要を見る

    The recombinant fragment of the platelet membrane glycoprotein, rGPIbalpha, was conjugated to phospholipid vesicles with the average diameter of ca. 1 mum using N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP). We used five kinds of rGPIbalpha-vesicles with different fluorescent anisotropies of 1,6-diphenyl-1,3,5-hexatriene (DPH) to study the rolling properties of the vesicles on the von Willebrand factor (vWf)-immobilized surface. Under flow conditions, the rolling velocity of the rGPIbalpha-vesicles decreased with the increasing membrane flexibility. It is considered that the vesicles with a high membrane flexibility have a high deformability and can be flattened to a high degree during rolling on the vWf surface, thus resulting in the large contact area. We obtained a recipe to control the rolling velocity of artificial platelets by membrane flexibility. (C) 2002 Elsevier Science (USA). All rights reserved.

    DOI

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    44
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  • Characteristics of bovine hemoglobin as a potential source of hemoglobin-vesicles for an artificial oxygen carrier

    H Sakai, Y Masada, S Takeoka, E Tsuchida

    JOURNAL OF BIOCHEMISTRY   131 ( 4 ) 611 - 617  2002年04月

     概要を見る

    Hemoglobin-vesicles (HbV) have been developed for use as artificial O-2 carriers in which a purified Hb solution is encapsulated within a phospholipid bilayer membrane. In this study, bovine Hb (BHb) was tested as a source of HbV instead of human Hb (HHb). We compared the preparation process and characteristics of BHbV with those of HHbV. The purification of BHb was effectively performed simply with an ultrafiltration system including a process for removing virus and scrapie agent. The removal ratio of the phospholipid components of bovine red blood cells was over 99.99%, and the protein purity was over 99.9%. The deoxygenated and carbonylated BHb showed denaturation transition temperatures at 83 and 87degreesC, respectively, which are higher than those of HHB (80 and 78degreesC, respectively), and resistant to pasteurization (60degreesC, 10 h). The purified BHb was concentrated to over 40 g/dl, and encapsulated in a phospholipid bilayer membrane to form BHbV with a diameter of about 280 nm. The O-2 affinity (P-50) of the BHbV was regulated by coencapsulation of an appropriate amount of Cl- (as NaCl), which binds to BHb as an allosteric effector, in the range 16-28 Torr, comparable to human blood (P-50 = 28 Torr). This is quite simple in comparison with HHb which requires phosphate derivatives such as pyridoxal 5-phosphate as a replacement for 2,3-diphoshoglyceric acid. The viscosity and colloid osmotic pressure of the BHbV when suspended in 5% human serum albumin are 3.5 cP and 20 Torr, respectively, comparable to those of human blood. In conclusion, BHb can be used as a source for the production of HbV, not only because of its abundance in the cattle industry, but also because of the physicochemical advantages of the purification process, thermal stability, and regulation of O-2 affinity in comparison with HHb.

  • Complete deoxygenation from a hemoglobin solution by an electrochemical method and heat treatment for virus inactivation

    YB Huang, S Takeoka, H Sakai, H Abe, J Hirayama, K Ikebuchi, H Ikeda, E Tsuchida

    BIOTECHNOLOGY PROGRESS   18 ( 1 ) 101 - 107  2002年01月

     概要を見る

    Hemoglobin (Hb) has been widely studied as a raw material for various types of oxygen carriers. In the purification of Hb from red blood cells including virus inactivation and denaturation of other proteins and the long-term storage of Hb vesicles (HbV), a deoxygenation process is one of the important processes because of the high stability of deoxygenated Hb to heating and metHb formation. Though an oxygenated Hb solution can be deoxygenated with an artificial lung, it is difficult to reduce the oxygen partial pressure of the Hb solution to less than 10 Torr. We developed an electrochemical system for complete deoxygenation of the Hb solution at the cathode compartment using hydrogen containing nitrogen gas at the anode compartment. Oxygen in the Hb solution was reduced to OH- at the cathode compartment within several minutes at a potential value of - 1.67 V and was finally converted to water by neutralization with H+ from the anode in the whole system. The resulting completely deoxygenated Hb could tolerate heat treatment at 62 degreesC for 10 h with no denaturation of deoxygenated Hb. The metHb formation rate of reoxygenated Hb at 37 degreesC was not changed after heat treatment. Furthermore, vesicular stomatitis virus (VSV) could be inactivated at an inactivation degree of more than 5.96 log by heat treatment.

    DOI

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    10
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  • Carbonylation of oxyhemoglobin solution (HbO2 → HbCO) using a membrane oxygenator

    I. Fukutomi, H. Sakai, S. Takeoka, E. Tsuchida, K. Sakai

    Journal of Artificial Organs   5 ( 2 ) 102 - 107  2002年

     概要を見る

    In the purification process of hemoglobin (Hb) from red blood cells, we stabilized Hb as carbonylhemoglobin (HbCO) against pasteurization at 60°C. In this study, the process of carbonylation (HBO2 → HbCO) was tested with a membrane oxygenator (CX-II08
    membrane area, 0.8m2
    maximum circulation rate, 1.21/min) under the conditions of a solution flow rate of 100-1000 ml/min and a CO gas flow rate of 30-100 ml/min. Comparing the overall O2 transfer coefficient of carbonylation with that of deoxygenation (N2 flow) revealed that the resistance to O2 transfer of carbonylation was about 35 times smaller, indicating that carbonylation hindered O2 rebinding (deoxyHb → HbO2). On the other hand, the O2 released in the course of carbonylation hindered carbonylation at the beginning, because rebinding of O2 is competitive with carbonylation. The time required for carbonylation was significantly shortened from 1000 to 150s when the solution flow rate was increased from 50 to 400 ml/min
    however, the CO gas flow rate did not affect it very much. Increasing the Hb concentration from 7.5 to 15 g/dl accelerated carbonylation by 1.3 times. Even though further study is necessary to select a suitable polymer membrane to avoid protein adsorption, a membrane oxygenator will be effective for the large-scale carbonylation of Hb as a starting material of HbV in the production process.

    DOI

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    6
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  • Virus removal from hemoglobin solution using planova membrane

    Y. Naito, I. Fukutomi, Y. Masada, H. Sakai, S. Takeoka, E. Tsuchida, H. Abe, J. Hirayama, K. Ikebuchi, H. Ikeda

    Journal of Artificial Organs   5 ( 2 ) 141 - 145  2002年

     概要を見る

    Hemoglobin (Hb) vesicles are artificial oxygen carriers that encapsulate concentrated purified Hb with a phospholipid bilayer membrane. They have been confirmed to have sufficient oxygen-transporting ability. Even though strictly inspected outdated red cells are used as a source of Hb, it is necessary to introduce an additional process that inactivates or removes viruses in the process of Hb purification in order to guarantee the utmost safety from infection. In this study, Hb filtration to remove viruses was tested with Planova 35N and 15N (virus removal fitters with a Bemberg microporous membrane). The permeation flux (LMH) and the permeated ratio of Hb solution ([Hb] = 5.6g/dl) through Planova 35N at 13°C were 361/m2/h and almost 100%, respectively. The values for Planova 15N at 13°C were 151/m2/h and 95%, respectively. The permeation flux increased to 181/m2/h when the temperature was raised to 25°C. Under the same conditions, a high efficiency of removal of a bacteriophage, φX174, was confirmed (&gt
    7.7log). These results indicate that Planova 15N is effective for the process of virus removal from Hb solution.

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    15
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  • 酸素輸液(ヘモグロビン小胞体)を含有する血清の生化学的検査

    酒井宏水, 富山賢一, 政田陽平, 武岡真司, 堀之内宏久, 小林紘一, 土田英俊

    人工血液   10   47 - 53  2002年

  • 酸素輸液の設計と開発動向

    武岡真司

    医薬の門   41;528-532   528 - 532  2001年10月

  • Hemoglobin-vesicles as oxygen carriers - Influence on phagocytic activity and histopathological changes in reticuloendothelial system

    H Sakai, H Horinouchi, K Tomiyama, E Ikeda, S Takeoka, K Kobayashi, E Tsuchida

    AMERICAN JOURNAL OF PATHOLOGY   159 ( 3 ) 1079 - 1088  2001年09月

     概要を見る

    Hemoglobin-vesicles (HbV) have been developed for use as artificial oxygen carriers (particle diameter, 250 nm) in which a purified Rb solution is encapsulated with a phospholipid bilayer membrane. The influence of HbV on the reticuloendothelial system was studied by carbon clearance measurements and histopathological examination. The HbV suspension ([Hb] = 10 g/dl) was intravenously infused In male Wistar rats at dose rates of 10 and 20 ml/kg, and the phagocytic activity was measured by monitoring the rate of carbon clearance at 8 hours and at 1, 3, 7, and 14 days after infusion. The phagocytic activity transiently decreased one day after infusion by about 40%, but it recovered and was enhanced at 3 days, showing a maximum of about twice the quiescent level at 7 days, and then returned to the normal value at 14 days. The initial transient decreased activity indicates a partly, but not completely, suppressed defensive function of the body. The succeeding increased phagocytic activity corresponds to the increased metabolism of HbV. The histopathological examination with anti-human Hb antibody, hematoxylin/eosin, and oil red O stainings; showed that HbV was metabolized within 7 days. Hemosiderin was very slightly confirmed with Berlin blue staining at 3 and 7 days in liver and spleen, though they completely disappeared at 14 days, indicating that the heme metabolism, excretion or recycling of iron proceeded smoothly and iron deposition was minimal. Electron microscopic examination of the spleen and liver tissues clearly demonstrated the particles of HbV with a diameter of about 1/40 of red blood cells in capillaries, and in phagosomes; as entrapped in the spleen macrophages and Kupffer cells one day after infusion. The vesicular structure could not be observed at 7 days. Even though the infusion of HbV modified the phagocytic activity for 2 weeks, it does not seem to cause any irreversible damage to the phagocytic organs. These results offer important information for evaluating the safety issues of HbV for clinical use.

  • Synthesis of disulfide-containing aniline and copolymerization with aniline

    JS Cho, S Sato, S Takeoka, E Tsuchida

    MACROMOLECULES   34 ( 9 ) 2751 - 2756  2001年04月

     概要を見る

    A novel disulfide-containing aniline, 1,4-dihydrobenzo[d] [1,2] dithiin-5-ylamin (1), was synthesized by the alkylbromination of 1,2-dimethyl-3-nitrobenzene, followed by the formation of a disulfide bond via thioesterification and then the reduction of the nitro group. The monomer showed a reductive and oxidative potential of the disulfide bond at -0.63 and 1.25 V (vs Ag/Ag+), respectively. Although the monomer showed the oxidative potential of aniline at 0.85 V (vs SCE), the electro- or chemical-oxidative polymerization of the monomer resulted in the formation of only the oligomer, suggesting that the disulfide-containing condensed ring would prevent further propagation of the polymerization due to steric hindrance. However, the nearly ideal copolymerization of 1 with aniline (An) was carried out by chemical oxidative polymerization. The resulting copolymers (1/An = 1/1 and 2/1, by mole) had weight-averaged molecular weights ((M) over bar (w)) of 10 000 and 6600, respectively and good redox activities coupled with those of the polyaniline and disulfide group. The copolymer showed conductivities of 5.1 x 10(-2) S/cm for 1/1 and 1.3 x 10-2 S/cm for 2/1 after being redoped with camphorsulfonic acid. It is suggested that these copolymers might be good candidates for the cathode materials of secondary polymer batteries.

    DOI

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    42
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  • Synthesis of disulfide-containing aniline and copolymerization with aniline

    JS Cho, S Sato, S Takeoka, E Tsuchida

    MACROMOLECULES   34 ( 9 ) 2751 - 2756  2001年04月

     概要を見る

    A novel disulfide-containing aniline, 1,4-dihydrobenzo[d] [1,2] dithiin-5-ylamin (1), was synthesized by the alkylbromination of 1,2-dimethyl-3-nitrobenzene, followed by the formation of a disulfide bond via thioesterification and then the reduction of the nitro group. The monomer showed a reductive and oxidative potential of the disulfide bond at -0.63 and 1.25 V (vs Ag/Ag+), respectively. Although the monomer showed the oxidative potential of aniline at 0.85 V (vs SCE), the electro- or chemical-oxidative polymerization of the monomer resulted in the formation of only the oligomer, suggesting that the disulfide-containing condensed ring would prevent further propagation of the polymerization due to steric hindrance. However, the nearly ideal copolymerization of 1 with aniline (An) was carried out by chemical oxidative polymerization. The resulting copolymers (1/An = 1/1 and 2/1, by mole) had weight-averaged molecular weights ((M) over bar (w)) of 10 000 and 6600, respectively and good redox activities coupled with those of the polyaniline and disulfide group. The copolymer showed conductivities of 5.1 x 10(-2) S/cm for 1/1 and 1.3 x 10-2 S/cm for 2/1 after being redoped with camphorsulfonic acid. It is suggested that these copolymers might be good candidates for the cathode materials of secondary polymer batteries.

    DOI

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    42
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  • Carbon monoxide from heme catabolism protects against hepatobiliary dysfunction in endotoxin-treated rat liver

    Takanori Kyokane, Shinji Norimizu, Hisashi Taniai, Tokio Yamaguchi, Shinji Takeoka, Eishun Tsuchida, Makoto Naito, Yuji Nimura, Yuzuru Ishimura, Makoto Suematsu

    Gastroenterology   120 ( 5 ) 1227 - 1240  2001年

     概要を見る

    Background &amp
    Aims: Liver is a major organ for heme detoxification under disease conditions, but its self-protective mechanisms against the toxicity are unknown. This study aimed to examine roles of carbon monoxide (CO), the gaseous product of heme oxygenase (HO), in ameliorating hepatobiliary dysfunction during catabolism of heme molecules in endotoxemic livers. Methods: Vascular resistance and biliary flux of bilirubin-IXα, an index of HO-derived CO generation, were monitored in perfused livers of endotoxemic rats. Livers were perfused with HbO2, which captures nitric oxide (NO) and CO, or metHb, a reagent trapping NO but not CO. Results: In endotoxin-pretreated livers where inducible NO synthase and HO-1 overproduced NO and CO, HbO2 caused marked vasoconstriction and cholestasis. These changes were not reproduced by the NO synthase inhibitor aminoguanidine alone, but by coadministration of zinc protoporphyrin-IX, an HO inhibitor. CO supplementation attenuated the events caused by aminoguanidine plus zinc protoporphyrin-IX, suggesting that simultaneous elimination of these vasorelaxing gases accounts for a mechanism for HbO2-induced changes. This concept was supported by observation that metHb did not cause any cholestasis
    the reagent captures NO but triggers CO overproduction through rapid degradation of the heme by HO-1. Conclusions: These results suggest protective roles of CO against hepatobiliary dysfunction caused by heme overloading under stress conditions.

    DOI PubMed

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    151
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  • Development of the Albumin Polymers with the Hemostotic Ability

    Blood・Immunity・Cancer   6 ( 1 ) 46  2001年

  • Effects of poly(ethyleneglycol)-modified hemoglobin vesicles on N-formyl-methionyl-leucylphenylalanine-induced responses of polymorphonuclear neutrophils in vitro

    T Ito, M Fujihara, H Abe, M Yamaguchi, S Wakamoto, S Takeoka, H Sakai, E Tsuchida, H Ikeda, K Ikebuchi

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND IMMOBILIZATION BIOTECHNOLOGY   29 ( 6 ) 427 - 437  2001年

     概要を見る

    [Poly(ethylene-lycol)]-modified hemoglobin vesicles (PEG-HbV), a type of encapsulated hemoglobin, have been developed as artificial oxygen carriers and it is important to evaluate their blood compatibility. We studied the effects of PEG-HbV on human polymorphonuclear neutrophils (PMNs) in vitro, focusing on the functional responses to N-formyl-methionyl-leucyl-phenylalanine (fMLP) as an agonist. The pretreatment of the PMNs with PEG-HbV up to a concentration of 60 mg/dl Hb did not affect the fMLP-triggered chemotactic activity. In parallel to these results, the fMLP-induced upregulation of CD11b (Mac-1) levels on the PEG-MV-pretreated PMNs was comparable to that of untreated cells. Furthermore, the pretreatment of the PMNs with the PEG-HbV even at 600 mg/dl Hb did not affect the gelatinase B (Matrix methalloproteinase-9 (MMP-9)) release, suggesting that the fMLP-induced release of secondary and tertiary granules was normal. In addition, the fMLP-triggered superoxide production of the PMNs was unchanged by the pretreatment with the PEG-HbV at 600 mg/dl Hb. Thus. these results suggest that PEG-HbV, at the concentrations studied, have no aberrant effects on the fMLP-triggered functions of human PMNs.

    DOI

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    11
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  • Virus inactivation in hemoglobin solution by heat treatment

    H Abe, K Ikebuchi, J Hirayama, M Fujihara, S Takeoka, H Sakai, E Tsuchida, H Ikeda

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND IMMOBILIZATION BIOTECHNOLOGY   29 ( 5 ) 381 - 388  2001年

     概要を見る

    To increase the safety of stroma-free hemoglobin solution (SFH) as an artificial oxygen carrier source, we investigated the effect of heat treatment on virus inactivation in hemoglobin solution. The hemoglobin solution spiked with vesicular stomatitis virus (VSV) was treated at 60 degreesC for 1 hr under either an air or CO atmosphere. VSV was inactivated at &gt;5.8 log(10) and &gt;6.0 log(10) under the air and CO atmosphere, respectively. Although the methemoglobin rate increased after the heat treatment under the air atmosphere, no methemoglobin formation was observed by the treatment under the CO atmosphere. Isoelectric focusing analysis revealed the denaturation of hemoglobin after the heat treatment under the air, while hemoglobin banding was not altered in the carbonylated condition. Some protein bands other than hemoglobin were weakened or disappeared on SDS-PAGE after the heat treatment under both conditions. In addition, the hemoglobin concentration in the SFH was higher after the heat treatment than before the treatment. These findings indicate that the heat treatment under the CO atmosphere inactivates viruses without hemoglobin denaturation, and hence, this method is a promising approach to prepare a safer SFH as artificial oxygen carriers.

    DOI

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    20
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  • Fibrinogen-conjugated albumin polymers and their interaction with platelets under flow conditions

    S. Takeoka, Y. Teramura, Y. Okamura, M. Handa, Y. Ikeda, E. Tsuchida

    Biomacromolecules   2 ( 4 ) 1192 - 1197  2001年

     概要を見る

    Albumin polymers, having an average diameter of 1020 ± 250 nm, were prepared by the disulfide polymerization of recombinant human serum albumin (rHSA) by controlling of the pH and temperature. Fibrinogen could be conjugated on the surface of an albumin polymer using N-succinimidyl 3-(2-pyridyldithio)propionate (SPDP). Under flow conditions, the fibrinogen-conjugated albumin polymers (fibrinogen-albumin polymers) were irreversibly attached to the platelet-immobilized surface in the reconstituted blood at a low platelet concentration ([platelet] = 5.0 × 104/μL, a 5-fold diluted platelet concentration), and the attachment was suppressed by the addition of anti-GPIIb/IIIa monoclonal antibodies. It was confirmed that fibrinogen-albumin polymers specifically interacted with GPIIb/IIIa expressed on the surface of the activated platelets. Although platelets with a low platelet concentration were hardly attached to the platelet-immobilized surface under the flow conditions, the addition of fibrinogen-albumin polymers enhanced the attachment of the remaining platelets to the surface, indicating that the fibrinogen-albumin polymers would help the hemostatic ability of platelets at the site of vascular injury of patients in thrombocytopenia.

    DOI PubMed

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    36
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  • Effects of poly(ethyleneglycol)-modified hemoglobin vesicles on agonist-induced platelet aggregation and RANTES release in vitro

    S Wakamoto, M Fujihara, H Abe, H Sakai, S Takeoka, E Tsuchida, H Ikeda, K Ikebuchi

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND IMMOBILIZATION BIOTECHNOLOGY   29 ( 3 ) 191 - 201  2001年

     概要を見る

    We studied the effects of hemoglobin-vesicles modified with PEG (PEC-HbV), a type of liposome-encapsulated hemoglobin (LEH), on human platelet functions in vitro. The effect of a low concentration of PEG-HbV (Hb; 5.8 mg/dl) was assessed by examining an agonist-induced aggregation response, and that of relatively high concentrations of PEG-HbV (Hb; 0.29, 1 and 2 g/dl) by measuring the release of RANTES (Regulated upon activation, normal T-cell expressed and presumably secreted) from platelets, which is regarded as a marker of platelet activation. The preincubation of platelets with PEG-HbV at 5.8 mg/dl of Hb did not affect platelet aggregation induced by collagen, thrombin and ristocetin. The pretreatment of platelet-rich plasma (PRP) with PEG-HbV at concentrations up to 2 g/dl of Hb had no aberrant effects on the collagen-induced RANTES release. Furthermore, the collagen-induced release of RANTES from PRP was not affected by longer incubation with PEG-HbV at 2 g/dl of Hb. The basal levels of RANTES from PRP were unchanged in the presence of PEG-HbV. These results suggest that PEG-HbV, at the concentrations studied, have no aberrant effects on platelet functions in the presence of plasma.

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    17
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  • 止血能を有するアルブミン重合体の開発.

    武岡真司, 寺村裕治, 土田英俊, 池田康夫

    血液・免疫・腫瘍/メディカルレビュー社   6 ( 1 ) 46 - 50  2001年01月

    J-GLOBAL

  • 粒子径を制御したアルブミン重合体の合成とGPIbα結合体の評価.

    寺村裕治, 武岡真司, 土田英俊, 池田康夫

    人工血液   8   90 - 95  2000年12月

    CiNii

  • Photoreduction of methemoglobin by irradiation in the near-ultraviolet region

    H Sakai, H Onuma, M Umeyama, S Takeoka, E Tsuchida

    BIOCHEMISTRY   39 ( 47 ) 14595 - 14602  2000年11月

     概要を見る

    Ferric metHb can be photoreduced to the ferrous state by direct photoexcitation in the near-ultraviolet region. In this research, we studied the mechanism and facilitating conditions for the photoreduction and the resulting restoration of O-2 binding. MetHb in phosphate-buffered saline or pure water in a CO atmosphere was photoreduced to form HbCO by illuminating the N band (365 nm), one of the porphyrin pi --&gt; pi* transitions, whereas the photoreduction did not occur in Ar, N-2, or O-2. The transient absorption spectrum exhibited the generation of deoxyHb within 30 ns in both the CO and Ar atmospheres; however, only in CO did the subsequent CO binding inhibit the back reaction. The photoreduction rate was dependent on the pH and ligand anions, showing that aquametHb in the high-spin state was predominant for the photoreduction. Axial ligand-to-metal charge-transfer (LMCT) bands overlap with the Soret and Q bands in metHb; however, the excitation of these bands showed little photoreduction, indicating that the contribution of these LMCT bands is minimal. Excitation of the N band significantly contributes to the photoreduction, and this is facilitated by the external addition of mannitol, hyaluronic acid, Trp, Tyr, etc. Especially, Trp allowed the photoreduction even in an Ar atmosphere, and the reduced Hb can be converted to HbO(2) by O-2 bubbling. One mechanism of the metHb photoreduction that is proposed on the basis of these results consists of a charge transfer from the porphyrin ring to the central, ferric iron to form the porphyrin pi cation radical and ferrous iron by the N band excitation, and the contribution of the amino acid residues in the globin chain as an electron donor or an electron pathway.

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  • Synthesis of multiacyl poly(ethylene glycol) for the conjugation of cytochrome c to phospholipid vesicle

    H Ohkawa, Y Teramura, S Takeoka, E Tsuchida

    BIOCONJUGATE CHEMISTRY   11 ( 6 ) 815 - 821  2000年11月

     概要を見る

    To conjugate water-soluble macromolecules on the surface of phospholipid vesicles, we synthesized a poly(ethylene glycol) (PEG)-lipid having four acyl chains using a lysine (Lys)-type monodendron structure. One end of the diamino-PEG was amidified with Lys, and then two amino groups of the Lys moiety were amidified with two Lys derivatives which had been acylated with two stearoyl groups. The other end of the PEG was activated with a triazine group or a pyridyldithio group. The hydrate of the lipid mixture of dipalmitoylphosphatidylcholine, cholesterol, dipalmitoylphosphatidylglycerol, and the PEG-lipid at a molar ratio of 5/5/1/0.3 was extruded in order to prepare the phospholipid vesicles with the average diameter of 270 +/- 20 nm. The coupling ratio of cytochrome c with the PEG-lipid was monitored by HPLC, detecting the pyridyl 2-thione liberated from the pyridyldithio group and determining it to be 26% on the basis of the incorporated PEG-lipid.

    DOI

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    4
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  • Synthesisi and physicochemical characterization of Hb-based O2 carriers: Comparison between cellular and acelluar types

    8th International Symposium on Blood Substitutes    2000年11月

  • Molecular dimensions of Hb-based O-2 carriers determine constriction of resistance arteries and hypertension

    H Sakai, H Hara, M Yuasa, AG Tsai, S Takeoka, E Tsuchida, M Intaglietta

    AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY   279 ( 3 ) H908 - H915  2000年09月

     概要を見る

    The effect of molecular dimension of hemoglobin (Hb)-based O-2 carriers on the diameter of resistance arteries (A(0), 158 +/- 21 mu m) and arterial blood pressure were studied in the conscious hamster dorsal skinfold model. Cross-linked Hb (XLHb), polyethylene glycol (PEG)-conjugated Hb, hydroxyethylstarch-conjugated XLHb, polymerized XLHb, and PEG-modified Hb vesicles (PEG-HbV) were synthesized. Their molecular diameters were 7, 22, 47, 68, and 224 nm, respectively. The bolus infusion of 7 ml/kg of XLHb (5 g/dl) caused an immediate hypertension (+34 +/- 13 mmHg at 3 h) with a simultaneous decrease in A(0) diameter (79 +/- 8% of basal value) and a blood flow decrease throughout the microvascular network. The diameter of smaller arterioles did not change significantly. Infusion of larger O-2 carriers resulted in lesser vasoconstriction and hypertension, with PEG-HbV showing the smallest changes. Constriction of resistance arteries was found to be correlated with the level of hypertension, and the responses were proportional to the molecular dimensions of the O-2 carriers. The underlying mechanism is not evident from these experiments; however, it is likely that the effects are related to the diffusion properties of the different Hb molecules.

  • Synthesis and assembly of poly(ethylene glycol)-lipids with mono-, di-, and tetraacyl chains and a poly(ethylene glycol) chain of various molecular weights

    S Takeoka, K Mori, H Ohkawa, K Sou, E Tsuchida

    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY   122 ( 33 ) 7927 - 7935  2000年08月

     概要を見る

    We synthesized a series of amphiphiles with poly(ethylene glycol) [MW 2000 (PEG20), 5000 (PEG50), 12 500 (PEG125)] as a headgroup and one, two, or four palmitoyl chains (1C16, 2C16, or 4C16), using a lysine monodendron as a connector. The relationship between the hydrophilic-hydrophobic balance of the multiacyl PEG-lipids and the physicochemical characteristics in self- or co-assembly with phospholipids were studied. The PEG-lipids were easily synthesized by combination of a general liquid-phase peptide synthesis and the acylation of an amino acid. The PEG part of the PEG-lipid films was crystallized to show a typical spherulite pattern. The thermal properties and microscopic observation revealed the phase separation of PEG and acyl chain parts. The critical micelle concentrations (cmcs) mainly depend on the number of acyl chains rather than the molecular weight of the PEG chain, although the area per molecule is dependent on the molecular weight of the PEG chain rather than the number of the acyl chains. The gel-to-liquid crystalline phase transition temperature was increased with the increasing number of acyl chains and the decreasing molecular weight of the PEG chain. The PEG-lipids in the aqueous dispersions assemble to take fibrous structures with bimolecular thickness because of the intermolecular hydrogen bonding. The PEG-lipids were immobilized onto the surface of the phospholipid vesicles by simply adding their aqueous dispersions to the vesicle dispersion; however, they dissociated from the vesicles on dilution of the mixed dispersion because they were incorporated into the vesicles in an equilibrium state. To prevent the dissociation of the PEG-lipids, at least two and four acyl chains were required for PEG with M-W 5000 and 12 500, respectively. The aggregation of the vesicles by the addition of water-soluble polymers was significantly inhibited with the increasing molecular weight of the PEG chain. For the tight immobilization of the PEG-lipids with the long PEG chain onto the vesicular surface, an increased number of acyl chains is necessary, and the surface modification with the long PEG chains significantly increases the dispersion stability of the vesicles.

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  • Papers presented at PAT '99 - Tokyo - Editorial

    H Ohno, S Takeoka, K Oyaizu

    POLYMERS FOR ADVANCED TECHNOLOGIES   11 ( 8-12 ) 369 - 369  2000年08月

  • Proton-conduction in poly(alkylenecarbonate)/poly(thiophenylenesulfonic acid) composites

    JS Cho, Y Hayashino, K Miyatake, S Takeoka, E Tsuchida

    POLYMERS FOR ADVANCED TECHNOLOGIES   11 ( 8-12 ) 548 - 552  2000年08月

     概要を見る

    Highly sulfonated poly(thiopenylenesulfonic acid) (PTPSA) was prepared from a soluble polysulfonium salt precursor and mixed with poly(alkylenecarbonate) (PAC, alkylene ethylene, PEG; propylene, PPC; butylene, PBC). The PTPSA and PAC were Employed as a proton source for conduction and a flexible base matrix :for proton dissociation and conduction pathway, respectively. For the composites of PTPSA/PAC (3/1, 2/1, 2/1 and 1/2, by weight), the effect of alkyl chain lengths of PAC, temperature dependence of proton-conductivity, and water content on the composites was studied. The proton-conductivity of the PTPSA/PAC composites Increased with the increasing PTPSA portion. The PTPSA/PBC (3/1) composite shows the highest proton-conductivity of 1.5 x 10(-6) Scm(-1) at 30 degreesC. However, the increased incorporation of PTPSA does not contribute to producing the higher proton conduction the composites. Moreover, the PTPSA/PBC composite including 15 wt% of water retained the proton-conductivity of 7.2 x 10(-2) Scm(-1) at 240 degreesC, which could be the conductivity comparative to the Nafion membrane and thermal stability. Copyright (C) 2000 John Wiley & Sons, Ltd.

    DOI

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  • Poly(ethylene glycol)-modification of the phospholipid vesicles by using the spontaneous incorporation of poly(ethylene glycol)-lipid into the vesicles

    K Sou, T Endo, S Takeoka, E Tsuchida

    BIOCONJUGATE CHEMISTRY   11 ( 3 ) 372 - 379  2000年05月

     概要を見る

    The critical micelle concentrations of 1,2-dipalmitoyl-sn-glycero-3-phosphoethaanolamine-N-[monomethoxy poly(ethyleneglycol) (5000)] (PEG-DPPE) and its distearoyl analogue (PEG-DSPE) were 70 and 9 mu M, respectively, in buffer solutions ([Tris] = 20 mM, [NaCl] = 140 mM, pH 7.4) at 37 degrees C. When these PEG-Lipid micelle dispersions were mixed with the dispersions of phospholipid vesicles comprised of a C16 membrane, of which the carbon number is 16, or a C18 membrane, the PEG-lipid micelles were dissociated into monomers and then spontaneously incorporated into the surface of the preformed vesicles. The incorporation rates and the enthalpy changes during incorporation were measured with an isothermal titration microcalorimeter. The incorporation rate of PEG-DPPE was faster than that of PEG-DSPE, because the dissociation rate of the PEG-DPPE micelles was faster than that of PEG-DSPE micelles. The incorporation equilibrium constant of PEG-DSPE was larger than that of PEG;DPPE due to its slow dissociation rate from the membrane, caused by the stronger hydrophobic interaction. The combination of PEG-DSPE and the C18 membrane was the most thermodynamically stabilized pair. Furthermore, the dispersion stability of the surface-modified vesicles prepared by this spontaneous incorporation was analyzed by using the critical molecular weight of the polymer for the aggregation of vesicles. The aggregation of the vesicles was successfully supressed with an increase in the molecular weight of the PEG in the PEG-lipid and its incorporation ratio.

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  • Poly(ethylene glycol)-conjugation and deoxygenation enable long-term preservation of hemoglobin-vesicles as oxygen carriers in a liquid state

    H Sakai, K Tomiyama, K Sou, S Takeoka, E Tsuchida

    BIOCONJUGATE CHEMISTRY   11 ( 3 ) 425 - 432  2000年05月

     概要を見る

    The stability of hemoglobin vesicles (HbV) as an oxygen infusion was tested during the storage for 1 year at 4, 23, and 40 degrees C. The surface of the HbV was modified with poly(ethylene glycol) (PEG), and the suspension was deoxygenated with nitrogen bubbling. The samples stored at 4 and 23 degrees C showed a stable dispersion state for 1 year, though the sample stored at 40 degrees C showed the precipitation and decomposition of vesicular components, a decrease in pH, and 4% leakage of total Hb after 1 year. The PEG chains on the vesicular surface stabilize the dispersion state and prevent the aggregation and fusion due to their steric hindrance. The original metHb content (ca. 3%) before the preservation gradually decreased to less than 1% in all the samples after 1 month due to the presence of homocysteine inside the vesicles which consumed the residual oxygen and gradually reduced the trace amount of metHb. The rate of metHb formation was strongly dependent on the partial pressure of oxygen, and no increase in metHb formation was observed due to the intrinsic stability of the deoxygenated Hb. Preservation at 4 and 23 degrees C slightly reduced P-50 (increased the oxygen affinity) from 38 Torr to 32 and 31 Torr, respectively. These results indicate the possibility that HbV suspension can be stared at room temperature for at least I year.

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  • 酸素輸液の開発

    武岡真司

    日本医工学治療学会第14回学術大会/日本医工学治療学会    2000年02月

  • 人工血液の開発動向

    土田英俊, 酒井宏水, 武岡真司

    バイオサイエンスとインダストリー   58   252-255  2000年

  • Proton-conduction of perfluorooctanesulfonic acid/poly(propylene carbonate) composites

    JS Cho, Y Hayashino, K Miyatake, S Takeoka, E Tsuchida

    CHEMISTRY LETTERS   2000/1,44 ( 1 ) 44 - 45  2000年01月

     概要を見る

    To obtain proton-conducting organic materials with high conductivity under nonaqueous conditions, high thermal stability, and high resistance to acid, we prepared perfluorooctane-sulfonic acid (FOSA)/ poly(propylene carbonate) (PPC) composites with different weight ratios. The composite with the weight ratios of 3 shows a high proton-conductivity of 1.9 x 10(-5) S.cm(-1) at 30 degrees C under nonaqueous conditions.

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  • Synthesis and physicochemical characterization of a series of hemoglobin-based oxygen carriers: Objective comparison between cellular and acellular types

    H Sakai, M Yuasa, H Onuma, S Takeoka, E Tsuchida

    BIOCONJUGATE CHEMISTRY   11 ( 1 ) 56 - 64  2000年01月

     概要を見る

    A series of hemoglobin (Hb)-based O(2) carriers, acellular and cellular types, were synthesized and their physicochemical characteristics were compared. The acellular type includes intramolecularly cross-linked Hb (XLHb), polyoxyethylene (POE)-conjugated pyridoxalated Hb (POE-PLP-Hb), hydroxyethylstarch-conjugated Hb (HES-XLHb), and glutaraldehyde-polymerized XLHb (Poly-XLHb). The cellular type is Hb-vesicles (HbV) of which the surface is modified with POE (POE-HbV). Their particle diameters are 7 +/- 2, 22 +/- 2, 47 +/- 17, 68 +/- 24, and 224 +/- 76 nm, respectively, thus all the materials penetrate across membrane filters with 0.4 mu m pore size, though only the POE-HbV cannot penetrate across the filter with 0.2 mu m pore size. These characteristics of permeability are important to consider-an optimal particle size in microcirculation in vivo. POE-PLP-Hb ([Hb] = 5 g/dL) showed viscosity of 6.1 cP at 332 s(-1) and colloid osmotic pressure (COP) of 70.2 Torr, which are beyond the physiological conditions (human blood, viscosity = 3-4 cP, COP = ca. 25 Torr). XLHb and Poly-XLHb showed viscosities of 1.0 and 1.5 cp, respectively, which are significantly lower than that of blood. COP of POE-HbV is regulated to 20 Torr in 5% human serum albumin (HSA). HES-XLHb and POE-HbV/HSA showed comparable viscosity with human blood. Microscopic observation of human red blood cells (RBC) after mixing blood with POE-PLP-Hb or HES-XLHb disclosed aggregates of RBC, a kind of sludge, indicating a strong interaction with RBC, which is anticipated to modify peripheral blood flow in vivo. On the other hand, XLHb and POE-HbV showed no rouleaux or aggregates of RBC. The acellular Hbs (P(50) = 14-32 Torr) have their specific O(2) affinities determined by their structures, while that; of the cellular POE-HbV is regulated by coencapsulating an appropriate amount of an allosteric effector (e.g., P(50) = 18, 32 Torr). These differences in physicochemical characteristics between the acellular and cellular types indicate the advantages of the cellular type from the physiological points of view.

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  • Conjugation of von Willebrand factor-binding domain of platelet glycoprotein Ibα to size-controlled albumin microspheres

    Shinji Takeoka, Yuji Teramura, Haruki Ohkawa, Yasuo Ikeda, Eishun Tsuchida

    Biomacromolecules   1 ( 2 ) 290 - 295  2000年

     概要を見る

    Albumin microspheres (AMS), of which the average diameter is 240 ± 10 nm, were prepared by pH control and heat treatment. Cytochrome c and rGPIbα
    a water-soluble fragment of the α chain of a recombinant platelet glycoprotein (GP)Ib containing a von Willebrand factor (vWf)-binding site were selected as a receptor protein. Cytochrome c was used as a probe protein for monitoring. Onto the surface of the AMS and those proteins, N-succinimidyl 3-(2-pyridyldithio)propionate (SPDP) was reacted through the amide linkage to obtain PD-AMS, PD-cytochrome c, and PD-rGPIbα, respectively. The latter two were further reduced to SH-cytochrome c and SH-rGPIbα by dithiothreitol and conjugated with PD-AMS by a thiol - disulfide exchange reaction. The resulting AMS contain cytochrome c or rGPIbα of about 25000 or 2500 molecules, respectively. The addition of ristocetin to the rGPIbα-AMS in the presence of vWf caused specific aggregation. Furthermore, the rGPIbα-AMS enhanced the ristocetin induced platelet aggregation in a low platelet concentration (4.0 × 107/mL).

    DOI PubMed

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  • Preparation and properties of polyaniline doped with poly(thiophenylenesulfonic acid)

    K Miyatake, JS Cho, S Takeoka, E Tsuchida

    MACROMOLECULAR CHEMISTRY AND PHYSICS   200 ( 12 ) 2597 - 2601  1999年12月

     概要を見る

    A novel polyaromatic acid, poly(thiophenylenesulfonic acid) (PTPSA), prepared from a soluble precursor of poly(arylenesulfonium salt) was employed as a dopant for polyaniline (PAn). The electro-oxidative polymerization of aniline in PTPSA aqueous solution gives an electroactive PAn/PTPSA composite with three redox couples at 0.16, 0.53, and 0.71V (vs. SCE). Composites of different molar ratio ([SO3H]/[An] = 0.10, 0.21, 0.42, 0.50, 0.83, 1.67) was prepared in order to confirm the transformation from the emeraldine base to its PTPSA salt, where a quantitative doping reaction was observed by means of UV-VIS and IR measurements. The thennogravimetric analysis revealed that the composites do not decompose up to 200 degrees C in nitrogen atmosphere. The composite ([SO3H]/[An] = 0.50) shows an electrical conductivity of 1.5 S . cm(-1) at 30 degrees C and 3.0 x 10(-1) S . cm(-1) at 170 degrees C. The composite retains its conductivity after heating at 150 degrees C for 24 h.

    DOI

  • ポリオキシエチレン修飾と脱酸素化による酸素輸液(ヘモグロビン小胞体)の長期保存

    人工血液/日本血液代替物学会   7;105-110  1999年12月

  • Carbon monoxide overproduced by heme oxygenase-1 causes a reduction of vascular resistance in perfused rat liver

    Y Wakabayaski, R Takamiya, A Mizuki, T Kyokane, N Goda, T Yamaguchi, S Takeoka, E Tsuchida, M Suematsu, Y Ishimura

    AMERICAN JOURNAL OF PHYSIOLOGY-GASTROINTESTINAL AND LIVER PHYSIOLOGY   277 ( 5 ) G1088 - G1096  1999年11月

     概要を見る

    This study aimed to examine whether livers overexpressing heme oxygenase (HO)-1 could alter the vascular resistance through the vasorelaxing action of carbon monoxide (CO). The relationship among HO-1 expression, CO generation, and the vascular resistance was assessed in perfused rat Livers pretreated with hemin, an inducer of HO-1. At 18 h after the hemin treatment, Livers displayed marked increases in HO-1 expression in hepatocytes and venous CO flux and a reduction of the basal resistance. The reduction of the resistance in hemin-treated livers was canceled by administration of oxyhemoglobin, a reagent trapping both CO and nitric oxide (NO), but not by methemoglobin, which captures NO but not CO. Liposome-encapsulated oxyhemoglobin, which cannot access the space of Disse, did not cause vasoconstriction. Furthermore, these livers became less sensitive to endothelin-1, a vasoconstrictive peptide, than the untreated controls through mechanisms involving CO. On the other hand, at 12 or 24 h after the treatment when the HO-1 induction was not accompanied by CO overproduction, neither a decrease in the basal resistance nor vascular hyporeactivity to endothelin-1 was observed. These results suggest that CO overproduced in the extrasinusoidal compartment is a determinant of the HO-1-mediated vasorelaxation in the liver.

  • Non-invasive observation of resistance arteries in conscious hamsters fitted with dorsal skinfold windows

    Microcirculation Annual 1999/日本医学館   pp.91-92  1999年11月

  • 人工血液の製剤化技術とその物性評価

    第11回界面科学部会/日本油化学会    1999年11月

  • 分子集合を利用した細胞型人工赤血球の創製とその評価

    第10回バイオマテリアル研究会/高分子学会    1999年11月

  • ポリオキシエチレン結合デンドロン型脂質の合成と物性

    第48回高分子討論会/高分子学会    1999年10月

  • Hemoglobin-based oxygen carriers (1): Synthesis and physicochemical characterization of crosslinked, polymerized, polymer-conjugated and encapsulated hemoglobin

    The 5th International Symposium on Polymers for Advanced Technologies (Tokyo)    1999年09月

  • 活性酸素から考慮したヘモグロビン利用酸素輸液のセル構造の重要性

    第6回日本血液代替物学会年次大会/日本血液代替物学会    1999年09月

  • ヘモグロビンを用いる酸素輸液の合成と物性比較

    日本医工学治療学会第13回学術大会/日本医工学治療学会    1999年09月

  • Nonaqueous proton conduction in poly(thiophenylenesulfonic acid)/poly(oxyethylene) composite

    K Miyatake, K Fukushima, S Takeoka, E Tsuchida

    CHEMISTRY OF MATERIALS   11 ( 5 ) 1171 - +  1999年05月

     概要を見る

    A homogeneous composite of poly(thiophenylenesulfonic acid) (1)/poly(oxyethylene) (2) was prepared. The composite has a glass transition temperature at 5.0 degrees C and shows a proton conductivity of 1.2 x 10(-5) S cm(-1) at 30 degrees C under nonaqueous conditions. The conductivity increases with the temperature up to about 10(-3) S cm(-1). The composite film keeps the same conductivity value after treatment at 130 degrees C for 100 h.

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  • ヘモグロビン小胞体存在下におけるヒト末梢血単核細胞の各種サイトカイン産生の挙動

    人工血液/日本血液代替物学会   7; 1, 27-32  1999年04月

  • Microvascular responses to hemodilution with Hb vesicles as red blood cell substitutes: influence of O-2 affinity

    H Sakai, AG Tsai, RJ Rohlfs, H Hara, S Takeoka, E Tsuchida, M Intaglietta

    AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY   276 ( 2 ) H553 - H562  1999年02月

     概要を見る

    Phospholipid vesicles encapsulating purified hemoglobin (HbV) were developed to provide O-2-carrying capacity to plasma expanders. Microvascular perfusion was determined for HbV with different O-2 affinity (P-50 = 9, 16, and 30 mmHg) prepared by coencapsulating pyridoxal 5'-phosphate (PLP) at the molar ratios of[PLP]/[Hb] = 0, 0.5, and 3, respectively (cf. hamster blood, P-50: 28 mmHg), and suspended in 8 g/dl human serum albumin (HSA). Eighty percent of the red blood cell (RBC) mass of conscious Syrian golden hamsters fitted with dorsal skinfold windows was substituted with either of the HbV-HSA suspensions, washed hamster RBC suspended in HSA(RBC-HSA), and HSA alone. All three HbV-HSA groups and RBC-HSA groups showed stable blood pressure and heart rate, which could not be sustained with HSA alone. Only the HbV (P-50 = 9)-HSA group showed an increase in arterial O-2 tension (89.8 +/- 14.7 mmHg, baseline 58.4 +/- 4.0 mmHg) because of hyperventilation, and microvascular perfusion was decreased, indicating that facilitated O-2 unloading of HbV by decreasing the O-2 affinity (increasing P-50) with PLP as an allosteric effector is important. Microvascular perfusion and microvascular and interstitial O-2 tensions in the HbV (P-50 = 16 and 30)-HSA groups were significantly higher than those in the HSA group. The O-2 release rate from the HbV was 18-32 s(-1) vs. 4.4 s(-1) for RBC. Functional capillary density was improved from 17 to 41% on average by decreasing P-50 from 30 to 16 mmHg, which appears to be an optimal value for the P-50 in this system.

  • Photoexcitation and electron transfer reactions of zinc lipidporphyrins in DMSO

    T Ohgushi, ZC Li, FM Li, T Komatsu, S Takeoka, E Tsuchida

    JOURNAL OF PORPHYRINS AND PHTHALOCYANINES   3 ( 1 ) 53 - 59  1999年01月

     概要を見る

    The photophysical and photochemical properties of 5,10, 15,20-tetrakis{alpha,alpha,alpha,alpha-o-[2',2'-dimethyl-20'-((2"-(trimethylammonio)ethyl) phosphonatoxy)alkanamido]phenyl}porphinatozinc(II) (zinc lipidporphyrins, ZnLPs (C-10, C-18)) have been studied in homogeneous DMSO solution and compared with those of 5, 10,15,20-tetrakis{alpha,alpha,alpha,alpha-o-pivalamidophenyl}porphinatozinc(II) (ZnTpivPP) and tetrakis-phenylporphinatozinc(II) (ZnTPP). The fluorescence quantum yields of the ZnLPs were lower than that of ZnTPP, but their fluorescence lifetimes were relatively long. The electron transfer reactions from the photoexcited states of these Zn porphyrin complexes to several quinone derivatives were evaluated by fluorescence spectroscopy and laser hash photolysis. The efficiencies of oxidative quenching of the excited porphyrins via a dynamic process were significantly decreased by the presence of the bulky substituents on one side of the porphyrin macrocycle. This steric effect of the porphyrin side-chains was quantitatively examined by the Marcus classical treatment. (C) 1999 John Wiley & Sons, Ltd.

    DOI

  • Cancellation of nitric oxide- and carbon monoxide-dependent vasorelaxation elicited by acellular hemoglobin derivatives in endotoxemic rat liver

    T Kyokane, M Suematsu, M Naito, Y Nimura, Y Ishimura, S Takeoka, E Tsuchida

    HEPATOLOGY   28 ( 4 ) 447A - 447A  1998年10月

  • 酸素輸液の現状

    武岡真司

    組織培養工学/ニューサイエンス社   24;13, pp.488-492  1998年09月

  • Physical properties and packing states of molecular assemblies of synthetic glycolipids in aqueous dispersions

    S Takeoka, K Sou, C Boettcher, JH Fuhrhop, E Tsuchida

    JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS   94 ( 15 ) 2151 - 2158  1998年08月

     概要を見る

    Amidic glycolipids, 1,5-bis-O-aIkyl-N-maltooligonoyl-L-glutamate (1), having various lengths of two hydrocarbon chains (carbon number, m: 14, 16, 18) and maltooligotose with (glucose unit, n: 3, 5, 7) and a N-glycosidic lipid, 1,5-bis-O-octadecyl-N-maltopentaonosyl-L-glutamate (2) have been synthesized. The assembling structures were analyzed by microscopic observation, such as negatively stained TEM, cryo-TEM, and AFM. The glycolipid 1a (rn,n. 14,5) showed a fiber-like structure in all the observed temperatures, while 1b (16,5) showed a fiber-like structure when the hydrating temperature was above the gel-to-liquid crystalline phase transition temperature (T-c; 45 degrees C) and a large disk-like structure when incubated below the T-c. The glycolipid 1c (18,5) took a large disk-like structure after hydration of the powder above the T-c. The glycolipids 1d (18,3) and 1e (18,7) showed a mixture of large disks and large vesicles and a mixture of small disks and micelles, respectively. The N-glycosidic lipid, 2, with no amide linkage made a vesicular structure only. The preparation procedure using high shear stress, such as extrusion and sonication, converted the large disk of 1c to smaller assemblies, such as small disk-, cone-, and granule-like assemblies, depending on the preparation conditions. The glycolipid molecules in the planer part of the disk were packed so tightly that molecular mobility was very low even above the T-c(58 degrees C), and the reactivity of the saccharide chain against Concanavalin A was also very low, indicating that the high reactivity probably comes from the loose packing of saccharide chains around the edge part of the assemblies.

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  • Subcutaneous microvascular responses to severe hemodilution with hemoglobin-vesicles as red cell substitutes

    H Sakai, H Hara, H Kerger, AG Tsai, SI Park, S Takeoka, H Nishide, E Tsuchida, M Intaglietta

    JOURNAL OF VASCULAR RESEARCH   35   88 - 88  1998年08月

  • 酸素輸液展開の現状

    日本人工臓器学会セミナー    1998年07月

  • 人工赤血球開発の現状—長期保存と棚置きの可能性

    第25回日本低温医学会総会    1998年07月

  • Antioxidative dopant for thermal-resisting polypyrrole and its mechanism

    S Takeoka, T Hara, K Fukushima, K Yamamoto, E Tsuchida

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   71 ( 6 ) 1471 - 1476  1998年06月

     概要を見る

    In order to improve the thermal stability of the electric conductivity of polypyrrole (PPy), a series of aromatic sulfonate derivatives having acid-type substitute groups, such as -COOH, -OH, and -SO3H, were used as dopants. The PPy doped with these dopants showed excellent thermal stability of their electric conductivity, even at 150 degrees C in air. Especially, 2-hydroxy-5-sulfobenzoic acid, having one -COOH and one -OH, provided the highest thermal stability; the doped PPy maintained 95% of its initial conductivity, even after heating for 8 h at 150 degrees C in air. Furthermore, the PPy showed 20-times higher stability against long-term heating at 125 degrees C for 1000 h in comparison with PPy doped with p-methylbenzenesulfonic acid, which is conventionally used to provide high thermal stability. The thermal-stabilization mechanism has suggested that dopants having acidic substituents should suppress proton dissociation from the N-position of the PPy main chain and keep the pi-conjugation structure by supplying a proton from the acidic groups. Such a proton supplement was confirmed by the IR spectroscopy of deuterized PPy.

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  • 酸素輸液の現状

    土田英俊, 武岡真司

    組織培養工学   24 ( 13 ) 488 - 492  1998年06月

  • Subcutaneous microvascular responses to hemodilution with a red cell substitute consisting of polyethyleneglycol-modified vesicles encapsulating hemoglobin

    H Sakai, AG Tsai, H Kerger, SI Park, S Takeoka, H Nishide, E Tsuchida, M Intaglietta

    JOURNAL OF BIOMEDICAL MATERIALS RESEARCH   40 ( 1 ) 66 - 78  1998年04月

     概要を見る

    Phospholipid vesicles encapsulating purified hemoglobin [Hb vesicles (HbV); diameter 259 +/- 82 mm; oxygen affinity 31 mm Hg; [Hb] 5 and 10 g/dL] were developed to provide oxygen-carrying capacity to plasma expanders. Their function as a blood replacement was tested in the subcutaneous microvasculature of awake hamsters during severe hemodilution in which 80% of the red blood cell mass was substituted with suspensions of the vesicles in 5% human serum albumin (HSA) solution. Vesicles were tested with membranes that were unmodified (HbV/HSA) or conjugated with polyethyleneglycol (PEG) on the vesicular surface (PEG-HbV/HSA). The viscosity of 10 g/dL HbV/HSA was 8 cP at 358 s(-1) owing to the intervesicular aggregation, while that of 10 g/dL PEG-HbV/HSA was 3.5 cP, since PEG chains inhibit aggregation. Both materials yielded normal mean arterial pressure, heart rate, and blood gas parameters at all levels of exchange, which could not be achieved with HSA alone. Subcutaneous microvascular studies showed that PEG-HbV/HSA significantly improved microhemodynamic conditions (flow rate, functional capillary density, vessel diameter, and oxygen tension) relative to unmodified HbV/HSA. Even though the enhancement of PEG modification did not achieve the functional characteristics of the blood-perfused microcirculation, PEG reduced vesicular aggregation and viscosity, improving microvascular perfusion relative to the unmodified type. These results highlight the significance of microvascular analysis in the design of red cell substitutes and the necessity of surface modification of HbV to prevent aggregation. (C) 1998 John Wiley & Sons, Inc.

    DOI

  • Disklike assemblies of a synthetic glycolipid and their association with Concanavalin A

    S Takeoka, K Sou, T Ohgushi, E Tsuchida

    SUPRAMOLECULAR SCIENCE   5 ( 1-2 ) 159 - 162  1998年03月

     概要を見る

    A synthetic glycolipid, 1,5-bis-O-octadecyl-N-maltopentaonoyl-L-glutamate (1), was dispersed in aqueous media above its phase transition temperature to form sheet-like assemblies. They were changed to disk- and ellipsoid-like assemblies by extrusion and sonication, respectively. The structures, stabilities, and thermal properties were studied with microscopic, optical, and calorimetric methods. The disk-like assemblies were homogeneous and the most stable. They formed a unique complex with Concanavalin A (ConA) to become a rouleaux-like structure. (C) 1998 Elsevier Science Limited.

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  • Distribution of heme oxygenase isoforms in rat liver - Topographic basis for carbon monoxide-mediated microvascular relaxation

    N Goda, K Suzuki, M Naito, S Takeoka, E Tsuchida, T Tametani, M Suematsu

    JOURNAL OF CLINICAL INVESTIGATION   101 ( 3 ) 604 - 612  1998年02月

     概要を見る

    Carbon monoxide (CO) derived from heme oxygenase has recently been shown to play a role in controlling hepatobiliary function, but intrahepatic distribution of the enzyme is unknown. We examined distribution of two kinds of the heme oxygenase isoforms (HO-1 and HO-2) in rat liver immunohistochemically suing monoclonal antibodies. The results showed that distribution of the two isoforms had distinct topographic patterns: HO-1, an inducible isoform, was observed only in Kupffer cells, while HO-2, a constitutive form, distributed to parenchymal cells, but not to Kupffer cells. Both isoforms were undetectable in hepatic stellate cells and sinusoidal endothelial cells. Of the two isoforms, HO-2 in the parenchymal cell rather than HO-1 in the Kupffer cell, appears to play a major role in regulation of microvascular tone. In the perfused liver, administration of HbO(2), a CO-trapping reagent that can diffuse across the fenestrated endothelium into the space of Disse, elicited a marked sinusoidal constriction, while administration of a liposome-encapsulated Hb that cannot enter the space had no effect on the microvascular tone. These results suggest that CO evolved by HO-2 in the parenchymal cells, and released to the extrasinusoidal space, served as the physiological relaxant for hepatic sinusoids.

  • Evaluation of the oxygen transporting capability of hemoglobin vesicles

    S Takeoka, H Sakai, K Kobayashi, E Tsuchida

    BLOOD SUBSTITUTES PRESENT AND FUTURE PERSPECTIVES     171 - 184  1998年  [査読有り]

  • Differences in particle size and oxygen-binding affinity between gross-linked hemoglobin and hemoglobin vesicle

    S Takeoka, Y Mano, E Tsuchida

    OXYGEN HOMEOSTASIS AND ITS DYNAMICS   1   428 - 433  1998年

     概要を見る

    Modified hemoglobins (Hb) such as intramolecular cross-linked Hb are currently undergoing clinical tests. On the other hand, a Hb vesicle that encapsulates a purified and concentrated Hb solution with the bilayer membrane of phospholipids is expected to overcome the problems of the modified Hb. The differences in size and oxygen-binding affinity of the Hb vesicles and intramolecular cross-linked Hb were compared to discuss the difference in the cellular and acellular types of Hb-based oxygen carriers, which have oxygen-binding and dissociation equilibrium curves similar to those of red blood cells (RBCs). The particle sizes of the cross-linked Hb, the Hb vesicle, and RBC are 5, 250, and 8000 nm, respectively. The Hb solution shows the lowest viscosity, whereas the viscosity of the Hb vesicle is relatively high and similar to the RBC. The permeability of the membrane filters depends on the particle size: cross-linked Hb &gt; Hb vesicles &gt; RBC. The oxygen-binding and -releasing rates of the Hb vesicles are between those of the acellular Hb and RBC, which could be explained in terms of the total surface area of Hb and the oxygen diffusion in the concentrated Hb solution (36 g/dl) inside the Hb vesicle.

  • Effects of the pH-controlled hemoglobin vesicles by CO2 gas

    S Park, T Kose, M Hamasaki, S Takeoka, H Nishide, E Tsuchida

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND IMMOBILIZATION BIOTECHNOLOGY   26 ( 5-6 ) 497 - 506  1998年

     概要を見る

    The hemoglobin vesicle (HbV) is a red cell substitute encapsulating purified concentrated Hb in a phospholipid vesicle. In order to improve the oxygen carrying capability of HbV, the pH value of the Hb solution should be adjusted to 7.0 in the HbV preparation, and then the pH value should be adjusted to 7.4 where HbV functions as an oxygen carrier, because the maximum value of [Hb]/[Lipid] was obtained in which the pH of the Hb solution was 7.0, and the metHb formation rate was suppressed in the pH 7.4. Generally, the pH control of the inner aqueous phase of HbV is difficult by changing the pH in the outer phase. We could control the pH of the Hb solution from 7.4 to 7.0 by dissolving CO2 into the Hb solution, and after the preparation of HbV, the pH of HbV is changed to 7.4 by reducing the pressure. The resulting pH-controlled HbV by CO2 gas showed a high [Hb]/[Lipid] value of 1.7 with a low rate of metHb formation.

  • Oxygen releasing from cellular hemoglobin

    N Kawai, H Ohkawa, H Maejima, S Takeoka, H Nishide, E Tsuchida

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND IMMOBILIZATION BIOTECHNOLOGY   26 ( 5-6 ) 507 - 517  1998年

     概要を見る

    The oxygen-releasing behavior of hemoglobin vesicles (HbV) was measured in order to study the difference in oxygen dynamics inside and outside the cellular Hb using a conventional stopped now method and a newly developed stopped flow flash photolysis method. The partial pressure of oxygen in the solution outside the HbV was monitored with the lifetime of the triplet state of meso-tetraphenylporphinatozinc(II) bound to human serum albumin excited by the laser flash. The change in the partial pressure of oxygen outside the HbV showed a biphasic profile and was slower than that inside the HbV. The first phase shows the oxygen-releasing process from Hb near the phospholipid bilayer membrane, and the second phase is considered the process in which oxygen diffuses to the bulk aqueous region and reaches the equilibrium value.

  • Human serum albumin-bound synthetic hemes as an oxygen carrier: Determination of equilibrium constants for heme binding to host albumin

    T Komatsu, K Hamamatsu, S Takeoka, H Nishide, E Tsuchida

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND IMMOBILIZATION BIOTECHNOLOGY   26 ( 5-6 ) 519 - 527  1998年

     概要を見る

    Human serum albumin (HSA) incorporating synthetic tetraphenylporphinatoiron(II) derivatives (FeP1 or FeP2) can bind and release oxygen reversibly under physiological conditions (in aqueous media, pH 7.4, 37 degrees C). The maximal binding ratio of FeP1/HSA was estimated to be eight, and the stepwise equilibrium constants for FeP1 binding to HSA (K-1-K-8) ranged from 1.2x10(6) to 1.3x10(4) M-1. The major binding sites of FeP1 are presumably identical to those of hemin, bilirubin and long-chain fatty acids. The O-2-binding ability of the HSA-FeP can be regulated by changing the molecular structure of the incorporated hemes. The half-lifetime of the O-2-coordinated FeP2 in HSA was significantly longer than that of HSA-FeP1.

  • The heme oxygenase system in liver microcirculation: A key mechanism for hemoglobin degradation

    M Suematsu, Y Wakabayashi, N Goda, S Takeoka, E Tsuchida, Y Ishimura

    BLOOD SUBSTITUTES PRESENT AND FUTURE PERSPECTIVES   Chapt. 19, pp241-250   241 - 249  1998年

  • Differences in Oxygen Transport and Physical Properties Between Cellular and Acellular Hemoglobins

    Proceedings of VII International Symposium on Blood Substitutes   3B-05  1997年09月

  • Hemoglobin-Vesicles Prepared by Controlling the Interaction of Hemoglobin and Phospholipid Membrane

    Proceedings of VII International Symposium on Blood Substitutes   p39-b  1997年09月

  • Properties of and oxygen binding by albumin-tetraphenylporphyrinatoiron(II) derivative complexes

    Eishun Tsuchida, Katsutoshi Ando, Hiromitsu Maejima, Noriyuki Kawai, Teruyuki Komatsu, Shinji Takeoka, Hiroyuki Nishide

    Bioconjugate Chemistry   8 ( 4 ) 534 - 538  1997年07月

     概要を見る

    A hydrophobic tetraphenylporphyrinatoiron(II) derivative bearing a covalently bound axial imidazole [Fe(II)P] was efficiently and noncovalently bound into human serum albumin (HSA) up to an average of eight Fe(II)P molecules per HSA molecule. The aqueous solutions of the HSA-Fe(II)P complex provided a reversible and relatively stable oxygen adduct under physiological conditions (pH 7.4 and 37 °C). The half-life of the oxygen adduct (τ( 1/4 )) was 1 h at 37 °C in an air atmosphere. With Fe(II)-TpivPP (the so-called 'picket-fence heme') having no axial base, an oxygenated HSA-Fe(II)TpivPP complex was obtained using a 20-fold molar excess of 1,2-dimethylimidazole, but the τ( 1/4 ) was very short (ca. 10 min at 37 °C). The oxygen affinity [P( 1/4 )(O2)] and oxygen transporting efficiency (OTE) of HSA-Fe(II)P at 37 °C were 30 Torr and 22%, respectively. Furthermore, the oxygen-binding and dissociation rate constants (k(on) and ko(off)) are extremely high in comparison with those of hemoglobin. The HSA molecule binding eight Fe(II)P molecules can transport about 3.4 mL/dL of oxygen under physiological conditions, corresponding to about 60 % of the oxygen transporting amount of human blood.

    DOI PubMed

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  • Methemoglobin formation in hemoglobin vesicles and reduction by encapsukated thiols

    Shinji Takeoka, Hiromi Sakai, Takehiro Kose, Yuichi Mano, Yuriko Seino, Hiroyuki Nishide, Eishun Tsuchida

    Bioconjugate Chemistry   8 ( 4 ) 539 - 544  1997年07月

     概要を見る

    The hemoglobin vesicle (HbV) is a red cell substitute encapsulating purified concentrated Hb in a phospholipid vesicle. In order to suppress metHb formation or autoxidation, for the long-term maintenance of the oxygen transporting capability, a series of thiols (cysteine, Cys
    glutathione, GSH
    homocysteine, Hcy
    and acetylcysteine, Acy) were studied as reductants of metHb. Hcy and GSH showed a good suppressive effect on metHb formation, while Cys adversely accelerates the metHb formation at a rate twice that of the Hb solution without any reductants and Acy showed no change. The significant suppression by the coaddition of superoxide dismutase (SOD) and catalase to Cys indicated that Cys was easily oxidized by oxygen and simultaneously generates a large amount of active oxygens. The effective suppression of metHb formation by SOD and catalase was not observed for HbV containing no reductants, indicating that the generation of active oxygens from Hb itself is not significant. The coencapsulation of Hcy with Hb resulted in a low rate of metHb formation in HbV (initial rate, 1%/h) in vitro at oxygen partial pressure (P(O2)) of 142 Torr. The rate increased with decreasing P(O2), showed a maximum (2.2%/h) around P(O2) = 23 Torr, and then decreased to 0%/h at 0 Torr. From these results, it is suggested that the fast metHb formation rate in the blood circulation of Wistar rats injected with 20 vol % of the HbV solution would be mainly caused by the exposure of HbV to the low P(O2).

    DOI PubMed

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  • Evaluation of the capabilities of a hemoglobin vesicle as an artificial oxygen carrier in a rat exchange transfusion model

    Y Izumi, H Sakai, T Kose, K Hamada, S Takeoka, A Yoshizu, H Horinouchi, R Kato, H Nishide, E Tsuchida, K Kobayashi

    ASAIO JOURNAL   43 ( 4 ) 289 - 297  1997年07月

     概要を見る

    Encapsulation of hemoglobin within a liposome is one of the strategies in the development of artificial oxygen carriers. It maintains the oxygen transporting properties of hemoglobin and, at the same time, eliminates the side effects of cell free hemoglobin. Hemoglobin vesicles (HbV) are a type of liposome encapsulated hemoglobin. They have a particle size of approximately 250 nm, a hemoglobin concentration of 10 g/dl, and the oxygen affinity, P50, is regulated to 32 Torr. In this study the authors examined the oxygen transporting capability of HBV in vivo, by performing exchange transfusions in rats. Exchange transfusion (90% of the estimated circulatory volume) with HbV suspended in 5% albumin (containing 160 mEq/L, sodium and 107 mEq/L, chloride) was carried out in mate Wistar rats. Mean arterial pressure and heart rate were monitored through the arterial catheter. Arterial blood samples for gas analyses were also obtained from the arterial catheter. Abdominal aortic blood flow was measured by an ultrasonic pulsed Doppler flowmeter as an indicator of cardiac output. The oxygen tension of blood withdrawn from the right atrium was measured as an indicator of mixed venous oxygen tension. These values were employed to calculate oxygen delivery and consumption. Renal cortical and skeletal muscle tissue oxygen tensions were monitored as indicators of tissue perfusion. Five percent albumin and washed rat red blood cells suspended in 5% albumin containing 10 g/dl of hemoglobin, were employed as controls. At the completion of a 90% exchange transfusion, renal cortical and skeletal muscle tissue oxygen tensions, along with oxygen delivery and consumption, were sustained almost equally well with the HbV suspension compared to the washed rat red blood cell suspension, but declined significantly with the albumin suspension. The results indicate that the oxygen transporting capability of HbV was almost equivalent to that of rat red blood cells.

    DOI

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  • Reduction of methemoglobin via electron transfer across the bilayer membrane of hb vesicles

    S Takeoka, T Ohgushi, H Nishide, E Tsuchida

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   70 ( 5 ) 1171 - 1178  1997年05月

     概要を見る

    The hemoglobin vesicle (HbV) has a cellular structure which encapsulates concentrated Hb in the inner aqueous phase of a phospholipid bilayer vesicle. Hb is gradually autoxidized to methemoglobin (metHb), which can not bind oxygen during oxygen transport under physiological conditions. In order to reduce metHb in HbV, we evaluated the reduction of metHb by electron transfer across the bilayer membrane of HbV from a reductant added to the outer aqueous phase. Water-soluble methylene blue (MB) and hydrophobic ubiquinone 10 (UQ) were selected as electron mediators. Under a nitrogen atmosphere, the addition of the reduced form nicotinamide-adenine dinucleotide (NADH) to the outer aqueous phase of UQ-incorporated HbV showed only a slow reduction rate for metHb. On the other hand, when MB and NADH were added under a nitrogen atmosphere to HbV containing 40% metHb, a rapid decrease in the metHb percentage was observed. The entire reaction was controlled by a reaction with NADH and MB in the outer aqueous phase. Under aerobic conditions, the decrease in the efficiency of the metHb reduction and rapid oxidation after reaching the minimal metHb percentage were observed. This was confirmed to be due to the influence of hydrogen peroxide; the decrease was prevented by the co-encapsulation of catalase.

    DOI

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  • 臨床利用を目指す人工赤血球

    第46回高分子学会年次大会講演予行集   IIA16IL  1997年05月

  • O2 binding and dissociation and ligand exchange reaction of O2 with CO in polymer composite films of hemoglobin.

    S.I. Park, H. Sakai, S. Takeoka, H. Nishide, E. Tsuchida

    Polymer Adv. Technol.   8   366-370  1997年  [査読有り]

    DOI

  • 出血性ショックモデルを用いた人工酸素運搬体、ヘモグロビン小胞体の酸素運搬能の検討.

    吉津晃, 山畑健, 泉陽太郎, 堀之内宏久, 小林紘一, 朴晟翼, 酒井宏水, 西出宏之, 土田英俊

    人工血液   5   18-22  1997年  [査読有り]

  • Construction of artificial methemoglobin reduction systems in Hb vesicles

    S Takeoka, T Ohgushi, H Sakai, T Kose, H Nishide, E Tsuchida

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND IMMOBILIZATION BIOTECHNOLOGY   25 ( 1-2 ) 31 - 41  1997年

     概要を見る

    The hemoglobin vesicle (HbV) is a red cell substitute encapsulating purified concentrated Hb in a phospholipid vesicle. In order to suppress metHb formation for the long term maintenance of oxygen transporting capability in vivo, thiols (cysteine, Cys; homocysteine, Hey) were studied as reductants of metHb. Hey showed a suppressive effect on metHb formation, while Cys adversely accelerates metHb formation at the rate of twice the Hb solution without any reductants. The suppression of Cys-induced metHb formation by the addition of superoxide dismutase (SOD) and catalase indicated that Cys was easily oxidized by oxygen and simultaneously generated a large amount of active oxygens. The rate of metHb formation was influenced by PO2 and pH. Furthermore, the reducing systems (methylene blue (MB), NADH or ascorbic acid) were added to the outer aqueous phase of HbV, and the artificial reduction systems constructed through the bilayer membrane were evaluated.

  • Surface modification of hemoglobin vesicles with poly(ethylene glycol) and effects on aggregation, viscosity, and blood flow during 90% exchange transfusion in anesthetized rats

    H Sakai, S Takeoka, SI Park, T Kose, H Nishide, Y Izumi, A Yoshizu, K Kobayashi, E Tsuchida

    BIOCONJUGATE CHEMISTRY   8 ( 1 ) 23 - 30  1997年01月

     概要を見る

    Poly(ethylene glycol) (PEG(5000))-conjugated phosphatidylethanolamine was introduced onto the surface of hemoglobin vesicles (HbV); phospholipid vesicles encapsulating concentrated Hb (d = 0.257 +/- 0.087 mu m; P-50 = 32 Torr). The obtained PEG-modified HbV (HbV-PEG) was studied for use as a red cell substitute from the viewpoint of rheology, surface properties, and hemodynamics. The viscosity of the unmodified HbV suspended in saline ([Hb] = 10 g/dL) was 2.6 cP (shear rate = 358 s(-1), 37 degrees C), less than that of human blood (4 cP). However, when suspended in a 5 g/dL albumin solution (HbV/albumin), it increased to 8 cP due to the molecular interaction between albumin and vesicles, and the viscosity increased with decreasing shear rate, e.g., 37 cP at 0.58 s(-1). As for the HbV-PEG/albumin, on the other hand, the viscosity was 3.5 cP at 358 s(-1) and was comparable with that of human blood. Optical microscopy showed formless flocculated aggregates of the unmodified HbV, while no aggregates were confirmed for the HbV-PEG. The steric hindrance of PEG chains seemed to be effective in preventing intervesicular access and the resulting aggregation To estimate the flow profiles in the capillaries, the suspensions were allowed to penetrate through isopore membrane filters (pore size = 0.4-8 mu m, cf. capillary diameter = 4-10 mu m). The penetration rate of the HbV-PEG/albumin was higher than that of the unmodified HbV/albumin due to the suppression of aggregation, whereas both of them were significantly higher than that of human blood due to the smaller size of vesicles than RBC. Ninety percent exchange transfusion was performed with the HbV-PEG/albumin or HbV/albumin in anesthetized Wistar rats (n = 6). The blood flow in the abdominal aorta increased 1.5 times, and the total peripheral resistance decreased in the HbV-PEG/albumin-administered group in comparison with the HbV/albumin group. As for the blood gas parameters, the base excess and pH remained at higher levels in the HbV-PEG/albumin group, and the O-2 tension in mixed venous blood for the HbV-PEG/albumin group tended to be maintained at a higher level than that for the HbV/albumin group. Thus, the PEG modification of HbV reduced the viscosity by the suppression of aggregation and resulted in prompt blood circulation in vivo.

    DOI

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  • Construction of artificial methemoglobin reduction systems in Hb vesicles

    S Takeoka, T Ohgushi, H Sakai, T Kose, H Nishide, E Tsuchida

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND IMMOBILIZATION BIOTECHNOLOGY   25 ( 1-2 ) 31 - 41  1997年

     概要を見る

    The hemoglobin vesicle (HbV) is a red cell substitute encapsulating purified concentrated Hb in a phospholipid vesicle. In order to suppress metHb formation for the long term maintenance of oxygen transporting capability in vivo, thiols (cysteine, Cys; homocysteine, Hey) were studied as reductants of metHb. Hey showed a suppressive effect on metHb formation, while Cys adversely accelerates metHb formation at the rate of twice the Hb solution without any reductants. The suppression of Cys-induced metHb formation by the addition of superoxide dismutase (SOD) and catalase indicated that Cys was easily oxidized by oxygen and simultaneously generated a large amount of active oxygens. The rate of metHb formation was influenced by PO2 and pH. Furthermore, the reducing systems (methylene blue (MB), NADH or ascorbic acid) were added to the outer aqueous phase of HbV, and the artificial reduction systems constructed through the bilayer membrane were evaluated.

    DOI

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    17
    被引用数
    (Scopus)
  • Construction of artificial methemoglobin reduction systems in Hb vesicles

    S Takeoka, T Ohgushi, H Sakai, T Kose, H Nishide, E Tsuchida

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND IMMOBILIZATION BIOTECHNOLOGY   25 ( 1-2 ) 31 - 41  1997年

     概要を見る

    The hemoglobin vesicle (HbV) is a red cell substitute encapsulating purified concentrated Hb in a phospholipid vesicle. In order to suppress metHb formation for the long term maintenance of oxygen transporting capability in vivo, thiols (cysteine, Cys; homocysteine, Hey) were studied as reductants of metHb. Hey showed a suppressive effect on metHb formation, while Cys adversely accelerates metHb formation at the rate of twice the Hb solution without any reductants. The suppression of Cys-induced metHb formation by the addition of superoxide dismutase (SOD) and catalase indicated that Cys was easily oxidized by oxygen and simultaneously generated a large amount of active oxygens. The rate of metHb formation was influenced by PO2 and pH. Furthermore, the reducing systems (methylene blue (MB), NADH or ascorbic acid) were added to the outer aqueous phase of HbV, and the artificial reduction systems constructed through the bilayer membrane were evaluated.

    DOI

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    17
    被引用数
    (Scopus)
  • The oxygen carrying capability of hemoglobin vesicles evaluated in rat exchange transfusion models

    K Kobayashi, Y Izumi, A Yoshizu, H Horinouchi, SI Park, H Sakai, S Takeoka, H Nishide, E Tsuchida

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND IMMOBILIZATION BIOTECHNOLOGY   25 ( 4 ) 357 - 366  1997年

     概要を見る

    To evaluate the oxygen transporting capability of Hemoglobin vesicles (HbV) the physiological responses to 40% and 90% exchange transfusions with HbV in anesthetized rat were observed. Hb concentration of HbV dispersions is 10g/dL. HbV dispersed in phosphate buffered saline and HbV dispersed in 5% albumin solution were used as samples for 40% and 90% exchange transfusions, respectively. HbV surface-modified with polyoxyethylene (HbV-Poe) was also used in the 90% exchange transfusion. As controls, phosphate buffered saline, 5% albumin solution, and HbV containing methemoglobin and therefore deprived of oxygen transporting capabilities (metHbV) were administered as non-oxygen carrying fluids and washed rat red blood cells (ratRBC) as an oxygen carrying fluid. Measurements included mean arterial pressure, arterial blood gas analyses, aortic blood flow and renal cortical tissue oxygen tension. At the completion of the exchange transfusion renal cortical tissue oxygen tensions along with oxygen delivery and consumption were sustained almost equally well with the HbV dispersion compared to the washed rat red blood cell dispersion, but declined significantly in the phosphate buffered saline and albumin solutions. These results indicated that the oxygen transporting capability of HbV was almost equivalent to that of rat red blood cells. in the HbV-Poe group, aortic blood flow was sustained higher in comparison to the HbV group. As for the blood gas parameters, pH and venous oxygen tensions in the HbV-Poe group tended to be higher than those in the HbV group.

    DOI

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  • Critical molecular weight effects in the aggregation of phospholipid vesicles triggered by water-soluble polymers and an integrated glycolipid

    S Takeoka, K Sou, S Arase, T Ohgushi, E Tsuchida

    MACROMOLECULES   29 ( 25 ) 8132 - 8136  1996年12月

     概要を見る

    The intervesicular aggregation of phospholipid vesicles is induced by the addition of water-soluble polymers such as poly(ethylene glycol), dextran, etc. due to the interaction between the vesicular surface and the water-soluble polymers. The interaction can be expressed by the critical molecular weight (M(c)) of the water-soluble polymers for the aggregation of vesicles. The surface modification of vesicles with glycolipids (O-1,O-5-bis(octadecyl) N-maltooligonoyl-L-glutamate) accelerates the aggregation of vesicles induced by dextran; therefore, M(c) significantly decreased due to the surface modification. No dependence of phospholipid concentration and dextran concentration in an aqueous phase on the M(c) indicates that dextran does not act as a cross-linking agent among the vesicles. A clear dependence of the density of the saccharide chains on the vesicular surface on the M(c) suggests that dextran should adsorb on the surface of the vesicles by the interaction with the oligosaccharide chains on the surface and cause vesicular aggregation. A lower critical solution temperature was observed for this kind of interaction, and the critical temperature was controlled by changing the molecular weight of dextran.

    DOI

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  • Differences in Oxygen Transport and Physical Property Between Encapsulated Hemoglobin and Cell-free Hemoglobin

    TAKEOKA Shinji, SAKAI Hiromi, NISHIDE Hiroyuki, TSUCHIDA Eishun

    Keio University International Symposia for Life Sciences and Medicine   45   S83  1996年12月

    CiNii

  • Physiologic responses to exchange transfusion with hemoglobin vesicles as an artificial oxygen carrier in anesthetized rats: Changes in mean arterial pressure and renal cortical tissue oxygen tension

    Y Izumi, H Sakai, K Hamada, S Takeoka, T Yamahata, R Kato, H Nishide, E Tsuchida, K Kobayashi

    CRITICAL CARE MEDICINE   24 ( 11 ) 1869 - 1873  1996年11月

     概要を見る

    Objectives: To evaluate the oxygen transporting capabilities of hemoglobin vesicles by studying the physiologic responses to exchange transfusion with hemoglobin vesicles in anesthetized rats. Exchange transfusions with phosphate buffered saline, hemoglobin vesicles containing methemoglobin (and therefore, deprived of oxygen transporting capabilities), and washed rat red blood cells were used as controls.
    Design: Prospective, randomized, controlled trial.
    Setting: Department of Surgery, School of Medicine, Keio University.
    Subjects: Twenty-seven male Wistar rats.
    Interventions: The rats were anesthetized with an intraperitoneal injection of sodium pentobarbital (50 mg/kg). Catheters (PE-20 tubing, outer diameter 0.8 mm, inner diameter 0.5 mm) were introduced into the right jugular vein for infusion and the right common carotid artery for blood withdrawal and mean arterial pressure measurements. The left kidney was exposed by median abdominal incision, and a needle type polarographic oxygen electrode was placed in the left renal cortex for renal cortical tissue oxygen tension measurements.
    Measurements and Main Results: Phosphate buffered saline and methemoglobin vesicles were administered as nonoxygen-carrying fluids, and rat red blood cells as oxygen carrying fluid. Measurements included mean arterial pressure, arterial blood gas analysis, and renal cortical tissue oxygen tension as an indicator of systemic oxygen transport. In the rat red blood cell and hemoglobin vesicles groups, mean arterial pressure was sustained at the end of the exchange transfusion (82.3 +/- 27.5% and 73.5 +/- 11.5%, respectively, from the basal values). However, in the phosphate buffered saline and methemoglobin vesicles groups, mean arterial pressure decreased significantly (p &lt;.05) (33.9 +/- 13.8% and 35.7 +/- 8.2%, respectively). Renal cortical tissue oxygen tension in the rat red blood cell and hemoglobin vesicles groups was sustained at a significantly higher level (p &lt;.05) (83.5 +/- 9.3% and 75.0 +/- 11.9%, respectively) compared with the phosphate buffered saline and methemoglobin vesicles groups (44.9 +/- 12.8% and 58.3 +/- 6.2%, respectively) at the end of the exchange transfusion. Metabolic acidosis was more progressive in the phosphate buffered saline and methemoglobin vesicles groups, manifested as lower pH and base excess values. Platelet counts tended to decrease slightly in the hemoglobin vesicles and methemoglobin vesicles groups, but the changes were not significant.
    Conclusions: Hemoglobin vesicles have an oxygen transporting capability almost equivalent to rat red blood cells and can be considered as a potential artificial oxygen carrier.

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  • Current Issues in Blood Substitute Research and Development

    人工血液/日本サイマルインターナショナル   4;3  1996年09月

  • Methemoglobin Reduction of Hemoglobin-Vesicles by Thiols

    International Symposium on High-Tech Polymers and Polymer Complexes/蘭州    1996年08月

  • Functional Evaluation of hemoglobin- and lipidheme-vesicles as red cell substitutes

    H Sakai, K Hamada, S Takeoka, H Nishide, E Tsuchida

    POLYMERS FOR ADVANCED TECHNOLOGIES   7 ( 8 ) 639 - 644  1996年08月

     概要を見る

    The two kinds of veri cell substitutes, hemoglobin-vesicles (HbV) and lipidheme-vesicles (LihV, totally synthetic oxygen carrier), were evaluated in terms of physicochemical properties such as binding and dissociating reactions of ligands (CO, O-2 and NO), rheological and structural properties. Carbonylation of Hb during the purification of Hb and the preparation of HbV is effective to prevent Hb denaturation. The rates of oxygenation of both HbV and LihV are faster than that of I ed blood cells (RBC). Their oxygen affinities (P-50, HbV, 32 mmHg; LihV, 43 mmHg, cf. RBC, 28 mmHg) can be controlled to transport a sufficient amount of oxygen comparable with that of RBC. The smaller sizes of vesicles are advantageous for prompt ligand reaction and low viscosity. Both HbV and RBC show about 100 times less vasoconstrictive effects than stripped Hb. HbV shows only one sixth of the slow binding rate of NO (=endothelial derived relaxation factor) in comparison with stripped Hb. Inhibition of vasoconstriction by those vesicles is discussed from the kinetic data.

    DOI

  • Layer-controlled hemoglobin vesicles by interaction of hemoglobin with a phospholipid assembly

    S Takeoka, T Ohgushi, K Terase, T Ohmori, E Tsuchida

    LANGMUIR   12 ( 7 ) 1755 - 1759  1996年04月

     概要を見る

    Hemoglobin vesicles, which encapsulated concentrated hemoglobin (Hb) with a bilayer of dipalmitoylphosphatidylcholine/cholesterol/palmitic acid, were prepared under various preparation conditions in order to decrease the number of bilayers (n) constructing the vesicle and increase the Ho concentration in the interior of the vesicle ([Hb](in)). n decreased when the surface potential of the bilayer became more negative because of the electrostatic repulsion between the bilayers, while with a changing xi-potential of Hb from positive to negative, [Hb](im) showed a precipitous fall because of the electrostatic repulsion between Hb and the surface of the bilayer. A temperature decrease leads to a quality increase in the Hb vesicles ([Hb]/[lipid]) in spite of the [Hb](in) decrease by the viscosity increase of the Hb solution. This is explained by the effective reduction of n due to the reduction in membrane fluidity and the protonation of Hb.

    DOI

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  • Oxygen Transporting Ability and Solution Properties of Stabilized Hemoglobin-Vesicles (HbV)

    24th Congress of the International Society of Blood Transfusion/東京    1996年04月

  • 赤血球代替物の近況

    医学のあゆみ/医歯薬出版   117;2  1996年02月

  • Efficacy of synthetic oxygen-carrying substances

    K Kobayashi, Y Izumi, T Yamahata, H Sakai, S Takeoka, H Nishide, E Tsuchida

    SHOCK   1102   305 - 310  1996年  [査読有り]

     概要を見る

    The oxygen-transporting capabilities of two types of liposome-encapsulated hemoglobins, neo red cells (NRC) and hemoglobin vesicles (HbV) were evaluated.
    NRC have a particle size of approximately 200 nm; hemoglobin concentration is 5 g/dl and its P-50 is controlled to 45 Torr.
    The oxygen-transporting capabilities of NRC were assessed by applying it as a perfusate for total cardiopulmonary bypass in male beagle dogs. Approximately 75% of the estimated circulatory volume was exchanged with NRC and total cardiopulmonary bypass was initiated. The rate of flow was altered during the experiment, the oxygen consumption reached a plateau at 9.3 ml/kg/min where oxygen delivery was 16.7 ml/kg/min. At this point the oxygen consumed per gram of hemoglobin from NRC was equivalent to that from dog red cells indicating that an almost equal amount of oxygen was consumed from NRC compared to dog red cells.
    The other type of liposome-encapsulated hemoglobin, HbV, has a particle size of approximately 250 nm. Hemoglobin concentration is 10 g/dl and its P-50 is controlled to 32 Torr.
    Exchange transfusion with HbV (40% of the estimated circulatory volume) was carried out in male Wistar rats. Mean arterial pressure, renal cortical tissue, and oxygen tension were monitored together with arterial blood gas measurements. Phosphate buffer saline (PBS), washed rat red blood cells containing 10 g/dl of hemoglobin (rat RBC) and HbV containing methemoglobin (met HbV) were employed as controls. After the exchange transfusion mean arterial pressure and renal cortical tissue oxygen tension were sustained in the HbV and rat RBC groups but declined significantly in the PBS and metHbV groups. These data indicate that the oxygen-carrying capabilities of HbV are almost equivalent to that of rat RBC.

  • ワークシヨツプ(5)

    武岡 真司, 西出 宏之, 土田 英俊, 高橋 恒夫, 仲井 邦彦, 末松 誠, 武岡 真司, 塩見 正哉, 若林 良之, 石村 巽, 土田 英俊, 福井 明, 泉 陽太郎, 酒井 宏水, 朴 晟翼, 武岡 真司, 西出 宏之, 土田 英俊, 小林 紘一

    人工臓器   25   S49 - S52  1996年

    DOI CiNii

  • 人工血液(1)

    高橋 恒夫, 柳田 尚之, 田中 三津子, 玉置 透, 川村 明夫, 石崎 彰, 岡野 正裕, 高橋 昌宏, 目黒 順一, 久木田 和丘, 米川 元樹, 緒方 嘉貴, 福井 秀男, 安藤 克利, 川合 宣行, 前島 浩光, 武岡 真司, 西出 宏之, 土田 英俊, 朴 晟翼, 武岡 真司, 酒井 宏水, 宗慶 太郎, 巨勢 丈裕, 西出 宏之, 土田 英俊, 泉 陽太郎, 吉津 晃, 小林 紘一

    人工臓器   25   S143 - S144  1996年

    DOI CiNii

  • "Efficacy of synthetic oxygen-carrying substances." In “Int. Congr. Ser. 1995, 1102 (Shock: from Molecular and Cellular Level to Whole Body).”

    K. Kobayashi, Y. Izumi, T. Yamahata, H. Sakai, S. Takeoka, H. Nishide, E. Tsuchida

    Elsevier     305-310  1996年

  • Physical properties of hemoglobin vesicles as red cell substitutes

    H Sakai, K Hamada, S Takeoka, H Nishide, E Tsuchida

    BIOTECHNOLOGY PROGRESS   12 ( 1 ) 119 - 125  1996年01月

     概要を見る

    Hemoglobin vesicles (HbV) as red cell substitutes were prepared from a purified carbonylhemoglobin (HbCO) solution and a lipid mixture composed of phospholipids, cholesterol, and cr-tocopherol. The diameter was controlled to 251 +/- 87 nm using an extrusion method; the vesicles penetrated through the membrane filters with regulated pore sizes. After the ligand exchanging reaction (HbCO --&gt; HbO(2)), the oxygen affinity (P-50) Of HbV was 32 Torr, which was controlled with the coencapsulation of pyridoxal 5'-phosphate. The rate of metHb formation in HbV was nonenzymatically reduced with the coencapsulation of DL-homocysteine. The Hb concentration of the HbV suspension, which was dispersed in a phosphate buffered saline solution (pH 7.4), was controlled at 10 g/dL. At this concentration, the total lipid concentration was 6.2 g/dL and the viscosity, 2.6 cP (230 s(-1)), was lower than that of the blood (4.4 cP). The HbV suspension showed a typical non-Newtonian flow for a particle dispersion and agreed well with the Casson model. The viscosity at shear rates lower than 23 s(-1) showed a maximum with increasing the mixing ratio of human blood, plasma, or albumin, while no maximum was observed for the mixture with washed red blood cells. The aggregates of HbV are formed by interaction with plasma proteins, including albumin, while the aggregates reversibly dissociate at higher shear rate.

    DOI

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  • Physical properties of hemoglobin vesicles as red cell substitutes

    H Sakai, K Hamada, S Takeoka, H Nishide, E Tsuchida

    BIOTECHNOLOGY PROGRESS   12 ( 1 ) 119 - 125  1996年01月

     概要を見る

    Hemoglobin vesicles (HbV) as red cell substitutes were prepared from a purified carbonylhemoglobin (HbCO) solution and a lipid mixture composed of phospholipids, cholesterol, and cr-tocopherol. The diameter was controlled to 251 +/- 87 nm using an extrusion method; the vesicles penetrated through the membrane filters with regulated pore sizes. After the ligand exchanging reaction (HbCO --&gt; HbO(2)), the oxygen affinity (P-50) Of HbV was 32 Torr, which was controlled with the coencapsulation of pyridoxal 5'-phosphate. The rate of metHb formation in HbV was nonenzymatically reduced with the coencapsulation of DL-homocysteine. The Hb concentration of the HbV suspension, which was dispersed in a phosphate buffered saline solution (pH 7.4), was controlled at 10 g/dL. At this concentration, the total lipid concentration was 6.2 g/dL and the viscosity, 2.6 cP (230 s(-1)), was lower than that of the blood (4.4 cP). The HbV suspension showed a typical non-Newtonian flow for a particle dispersion and agreed well with the Casson model. The viscosity at shear rates lower than 23 s(-1) showed a maximum with increasing the mixing ratio of human blood, plasma, or albumin, while no maximum was observed for the mixture with washed red blood cells. The aggregates of HbV are formed by interaction with plasma proteins, including albumin, while the aggregates reversibly dissociate at higher shear rate.

    DOI

    Scopus

    99
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  • Thermal stabilization of polypyrrole by incorporation of aromatic sulfonate derivatives as dopants

    S Takeoka, T Hara, K Yamamoto, E Tsuchida

    CHEMISTRY LETTERS   1996 ( 4 ) 253 - 254  1996年

     概要を見る

    Thermal stability of electric conductivity of polypyrrole (PPy) was improved using aromatic sulfonate derivatives as dopants having mobile hydrogen in the form of acid groups such as sulfonic acid, carboxylic acid, ol hydroxide groups. Particularly, when m-sulfobenzoic acid or 5-sulfosalicylic acid were used as dopants, the PPy showed high thermal stability of electric conductivity and kept 95% electric conductivity even after heating for 8h at 150 degrees C in air.

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    16
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  • ポリエチレングリコール型脂質および糖脂質によるヘモグロビン小胞体(HbV)の表面修飾効果

    朴 晟翼, 宗 慶太郎, 酒井宏水, 武岡真司, 西出宏之, 土田英俊

    人工血液   4   9 - 14  1996年

  • Rheological Characteristics of the Phospholipid Vesicles Surface-Modified with Oligosaccharide

    Pacific Polymer Conference (Hawaii)    1995年12月

  • DESTRUCTION AND RECONSTITUTION OF POLYPHOSPHOLIPID VESICLES WITH SIZE MEMORY

    S TAKEOKA, T OHGUSHI, E TSUCHIDA

    MACROMOLECULES   28 ( 23 ) 7660 - 7666  1995年11月

     概要を見る

    1,2-Bis(2,4-octadecadienoyl)-sn-glycero-3-phosphocholine (DODPC), constructing the bilayer membrane of a vesicle, was polymerized by UV irradiation. The freeze-dried vesicles were completely dissolved in chloroform to obtain cross-linked phospholipid polymer (polyDODPC). The polyDODPC consisted of high molecular weight components and oligomers. The polyDODPC was dispersed by sonication, and two size distributions of the reconstituted vesicles were confirmed, larger vesicles from high molecular weight polyDODPC and smaller vesicles from oligomers. When the polyDODPC vesicles of various sizes and unimodal size distribution were reconstituted by an extrusion method, the vesicles of the same size as the vesicles at polymerization showed excellent stability compared with the other sizes. Interestingly, the original size of the polyDODPC vesicles could be completely restored by a cholate dialysis method. It was also clarified that vesicles larger than the original size were reconstituted from the higher molecular weight component, and the smaller vesicles were from the oligomers. Furthermore, a linear phospholipid polymer obtained from 1-palmitoyl-2-(2,4-octadecadienoyl)-sn-glycero-3-phosphocholine could not restore the original size. Those results indicate that the original size of the vesicles can be restored completely by all polyDODPCs having the original composition of large and small molecular weights and cross-linked structure.

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    4
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  • INTERMOLECULAR INTERACTIONS OF LITHOCHOLIC ACID-DERIVATIVES WITH PHOSPHOLIPID AS BILAYER-MEMBRANE

    ZC LI, FM LI, S ARASE, S TAKEOKA, E TSUCHIDA

    LANGMUIR   11 ( 8 ) 3161 - 3166  1995年08月

     概要を見る

    Three single chain lithocholic acid derivatives with a steroidal moiety in the center of the hydrocarbon chain and two head groups at both ends of the chain were synthesized and characterized. Due to their high compatibility with phospholipids, they can be incorporated homogeneously into the phospholipid bilayer membrane. The resulting mixed vesicles showed high stability against aggregation by monitoring the turbidity change in the vesicle suspensions. The entire membrane-spanning packing thus locates the steroidal moiety at the center of the bilayer. The interaction of the steroidal moiety with Lipid molecules at the center of the bilayer resulted in higher mobility of lipid molecules below the T-c of the host phospholipid membrane as clarified by temperature-dependent H-1 NMR, fluorescence depolarization anisotropy, and differential scanning calorimetry (DSC). The results were compared with those of cholesterol, whose steroidal moiety is located near the surface of the membrane.

    DOI

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    1
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  • Modification of hemoglobin-vesicles with Oligosccharide Chains

    Artif. Organs Today/VSP   4;4  1995年04月

  • LIGAND-EXCHANGE REACTION OF CARBONYLHEMOGLOBIN TO OXYHEMOGLOBIN IN A HEMOGLOBIN LIQUID MEMBRANE

    JE CHUNG, K HAMADA, H SAKAI, S TAKEOKA, E TSUCHIDA

    NIPPON KAGAKU KAISHI   1995 ( 2 ) 123 - 127  1995年02月

     概要を見る

    In order to change carbonylhemoglobin (HbCO) to oxyhemoglobin(HbO(2)), the photodissociation of HbCO and O-2-binding to hemoglobin were studied using Hb liquid membrane system in O-2 atmosphere. The reduction rate of HbCO increased with illuminance and saturated nearly at 2.0 . 10(5) 1x. under a constant O-2 pressure of 760 Torr. The reduction rate of HbCO was a 5-fold low when the partial O-2 pressure was decreased from 760 to 0 Torr under the illuminance. In the static liquid membrane the exchanging rate of CO ligand in HbCO was decreased with the increment of the thickness of the liquid membrane, while the stirred liquid membrane showed a reverse result. The ligand exchange apparatus was made based on the obtained results, and the high flow rate of Hb solution enhanced the reduced amount of HbCO. Moreover, when the ligand exchange of Hb-vesicle dispersion was compared with an Hb solution, it proceeded more efficiently due to the encapsulation of concentrated Hb into a small compartment dispersed in a buffer solution.

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  • COORDINATION BEHAVIOR OF O-2 AND CO IN A SOLID FILM CONSISTING OF HEMOGLOBIN AND MALTOSE

    JF CHUNG, H SAKAI, S TAKEOKA, H NISHIDE, E TSUCHIDA

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   68 ( 3 ) 1006 - 1011  1995年

     概要を見る

    Solid hemoglobin (Hb) films were prepared by casting from a mixed solution of human hemoglobin and maltose (wt ratio of Hb/maltose is 60/40). The behavior of O-2 and CO in coordinating to Hb in the films was then observed. The coordination equilibrium constants of both ligands were smaller by about an order of magnitude, and the rate constants (K-on, and k(off)) were smaller by about 13 orders of magnitude, than those of aqueous solutions of Hb. Interestingly, O-2 and CO saturation was limited to 52% and 86%, respectively, under a partial pressure of 760 Torr (1 Torr=133.322 Pa) of each gas, in spite of the one-to-one ligand binding ratio in aqueous solutions. This is due to the restraint of the structural change from a tense to a relaxed state in the solid phase. The limited saturation of the coordination in the solid phase was found to increase to 100% when a small amount (5.9%) of water was added; a significant structural change from the tense to the relaxed states followed.

    DOI

  • Electronic Processes in Macromolecular Metal Complexes

    Macromolecular Metal Complexes/Springer-Verlag   Chapt.4  1995年

  • ヘモグロビン液膜のカルボニルヘモグロビンからオキシヘモグロビンへの配位子交換

    鄭 主恩, 濱田健一, 酒井宏水, 武岡真司, 土田英俊

    日化誌   1995 ( 2 ) 123 - 127  1995年

    DOI

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    20
    被引用数
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  • 赤血球代替物(NRC)の成分定量

    濱田健一, 巨勢丈裕, 大串 建, 酒井宏水, 武岡真司, 西出宏之, 土田英俊

    人工血液   3   96 - 101  1995年

  • ヘモグロビン液膜のカルボニルヘモグロビンからオキシヘモグロビンへの配位子交換

    鄭 主恩, 濱田健一, 酒井宏水, 武岡真司, 土田英俊

    日化誌   1995 ( 2 ) 123 - 127  1995年

    DOI

    Scopus

    20
    被引用数
    (Scopus)
  • 赤血球代替物(NRC)の成分定量

    濱田健一, 巨勢丈裕, 大串 建, 酒井宏水, 武岡真司, 西出宏之, 土田英俊

    人工血液   3   96 - 101  1995年

    CiNii

  • ヘモグロビン小胞体の酸素輸送に関するラット交換輸血試験

    酒井宏水, 泉 陽太郎, 山畑 健, 濱田健一, 武岡真司, 西出宏之, 小林紘一, 土田英俊

    人工血液   3   81 - 86  1995年

  • EFFECT OF A LITHOCHOLIC ACID-DERIVATIVE ON THE MOLECULAR PACKING AND STABILITY OF PHOSPHOLIPID-VESICLES

    ZC LI, FM LI, S ARASE, S TAKEOKA, E TSUCHIDA

    CHEMISTRY LETTERS   1994 ( 12 ) 2199 - 2202  1994年12月

     概要を見る

    A lithocholic acid derivative having high compatibility with phospholipid was synthesized and incorporated to the phospholipid bilayer membrane. A significant influence of it on the molecular packing and the stability enhancement of the vesicle suspension were clarified by a fluorescence depolarization method and a turbidity measurement, respectively.

    DOI

  • SUPPRESSION OF METHEMOGLOBIN FORMATION BY GLUTATHIONE IN A CONCENTRATED HEMOGLOBIN SOLUTION AND IN A HEMOGLOBIN-VESICLE

    H SAKAI, S TAKEOKA, Y SEINO, E TSUCHIDA

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   67 ( 4 ) 1120 - 1125  1994年04月

     概要を見る

    The suppression of methemoglobin (metHb) formation by glutathione (GSH) is difficult because GSH is oxidized not only by the reduction of metHb, but also by oxygen to generate active oxygen species, such as superoxide (O2-.) and hydrogen peroxide (H2O2), which contribute to metHb formation. An effective nonenzymatic reduction of metHb was achieved at a high concentration of Hb (40 wt%, 2.48 x 10(-2) M subunits (1 M = 1 mol dm-3)) because the reduction of metHb was accelerated, and at a low partial pressure of oxygen (pO2 = 40 Torr (1 Torr = 133.322 Pa)) because the oxidation of GSH was effectively suppressed. Hb-vesicles, which encapsulate concentrated Hb (40 wt%, 2.48 x 10(-2) M subunits), transport oxygen in the blood stream at relatively low pO2 (110 Torr in artery and 40 Torr in venous, 58 Torr in average). The rate of metHb formation in Hb-vesicles was effectively decreased from 3.8 x 10(-7) to 1.6 x 10(-7) M s-1 by coencapsulating GSH at 58 Torr.

    DOI

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    12
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  • INTERACTION BETWEEN PHOSPHOLIPIDS ASSEMBLY AND GLOBIN PROTEINS

    S TAKEOKA, H YOKOHAMA, K TERASE, E TSUCHIDA

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   207   145 - BTEC  1994年03月

  • Hb小胞体のin vitro, in vivo試験

    酒井 宏水, 濱田 健一, 武岡 真司, 西出 宏之, 土田 英俊, 泉陽 太郎, 小林 紘一

    人工臓器   23   S171a - S171a  1994年

    DOI CiNii

  • Oxygen‐binding property of hemoglobin films

    Jooeun Chung, Shinji Takeoka, Hiroyuki Nishide, Eishun Tsuchida

    Polymers for Advanced Technologies   5 ( 7 ) 385 - 389  1994年  [査読有り]

     概要を見る

    Oxygenated and deoxygenated hemoglobin films were obtained by drying corresponding hemoglobin solutions with maltose (≧0.3 M). The resulting hemoglobin films were homogeneous and smooth, and the methemoglobin formation in the oxyhemoglobin film was well suppressed. The dry, rigid networks of maltose molecules work to preserve the conformation of hemoglobin against the removal of water. The coordination of oxygen to the deoxygenated hemoglobin film was slow and saturated up to 50%, while nearly 100% saturation was achieved if the film contained a residual moisture of 8.7%. Copyright © 1994 John Wiley &amp
    Sons, Ltd.

    DOI

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    3
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  • Suppression of metHb formation in Hb-vesicles by glutathione.

    H. Yokohama, Y. Seino, J. E. Chung, H. Sakai, S. Takeoka, H. Nishide, E. Tsuchida

    Artif. Organs Today   4   107-116  1994年  [査読有り]

  • INTERACTION BETWEEN PHOSPHOLIPID ASSEMBLIES AND HEMOGLOBIN (HB)

    S TAKEOKA, K TERASE, H YOKOHAMA, H SAKAI, H NISHIDE, E TSUCHIDA

    JOURNAL OF MACROMOLECULAR SCIENCE-PURE AND APPLIED CHEMISTRY   A31 ( 1 ) 97 - 108  1994年

     概要を見る

    In order to prepare Hb-vesicles having a high oxygen-transporting ability, it is important to encapsulate concentrated Hb with a mixed lipid membrane having low lamellarity (n). The concentration of Hb in the Hb-vesicles ([Hb](in)) increased with the Hb concentration used for the preparation of Hb-vesicles. Hb-vesicles with smaller lamellarity could be obtained y lowering the preparation temperature. The encapsulation of Hb was significantly influenced by the ionic strength and the solution pH because lipids and Hb are electrolytes. The lamellarity decreases with increasing solution pH because of electrostatic repulsion between the surfaces of lipid membranes. On the other hand, [Hb](in) increases when the solution pH is lowered below the pI of Hb (7.0 at 25 degrees C) due to electrostatic interaction between Hb and the surface of the membrane. This interaction decreases with the ionic strength of the Hb solution, leading to a lower [Hb](in).

  • Extraction of purified Hb from red-cell by coexistence of organic media including polymers

    Tsuchida, E, Chung, JE, Seino, Y, Sakai, H, Takeoka, S

    Abstr. Pap. Am. Chem. Soc.   141   207  1994年

  • CHARACTERISTICS OF HB-VESICLES AND ENCAPSULATION PROCEDURE

    S TAKEOKA, H SAKAI, K TERASE, H NISHIDE, E TSUCHIDA

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND IMMOBILIZATION BIOTECHNOLOGY   22 ( 3 ) 861 - 866  1994年

     概要を見る

    The performance of Hb-vesicles depends on the weight ratio of Hb to lipid ([Hb]/[Lipid]). This value is improved by lowering the number of bilayer membrane of the vesicle and raising the concentration of Hb in the interior of the vesicle. Maximum [Hb]/[Lipid] ratio was obtained at ca. pH 7, that would relate to the isoelectric point (pl) of Hb at 25 degrees C. On the other hand, the [Hb]/[Lipid] ratio decreased with ionic strength and increased with lowering temperature. The Hb-vesicles encapsulating 40 g/dl Hb with only one bilayer membrane were isolated by using the difference in the density of the vesicles.

    DOI

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  • CONVENIENT METHOD TO PURIFY HEMOGLOBIN

    H SAKAI, S TAKEOKA, H NISHIDE, E TSUCHIDA

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND IMMOBILIZATION BIOTECHNOLOGY   22 ( 3 ) 651 - 656  1994年

     概要を見る

    A convenient method to purify Hb solution from outdated RBC has been established for the starting material of Hb-based blood substitutes. To prevent MetHb formation during the procedure, Hb in RBC was carbonylated in advance. Then RBC was mixed with organic solvent for hemolysis and centrifuged for removal of stroma. The resulting SFHb solution was heated at 60 degrees C and generated precipitates were removed out by centrifugation. The purity of Hb (25 g/dl) was confirmed by SDS-PAGE. IEF and oxygen binding property of the Kb solution also guaranteed its purity and no denaturation of Hb. This method is applicable to large scale production of the purified Hb for the starting material of Hb-based blood substitutes.

    DOI

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    8
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  • STABILIZED HEMOGLOBIN VESICLES

    E TSUCHIDA

    ARTIFICIAL CELLS BLOOD SUBSTITUTES AND IMMOBILIZATION BIOTECHNOLOGY   22 ( 3 ) 467 - 477  1994年

     概要を見る

    The Hb-vesicles which encapsulate the purified and concentrated Hb more than 40 g/dl with a uni- or bi-lamellar membrane are prepared by extruding the dispersion of mixed lipids through membrane filters (final pore size: 0.2 mu m phi). They transport large amount of oxygen with satisfying theological properties such as oncotic pressure and solution viscosity. Oxygen affinity of the Hb-vesicles is adjusted so as to exceed the ability of oxygen transport of human blood by coen-capsulating allosteric effecters in the Hb-vesicles. The solution is sterilizable because of the diameter of Hb vesicles less than 0.2 mu m phi. The Hb-vesicles are stabilized by using polyphospholipid or glycolipid as membrane components. No change in oxygen affinity and particle size was confirmed during long time storage at 4 degrees C. The stabilized Hb-vesicles can also be stored as frozen or dried state. The dried Hb-vesicles are regenerated by simply adding pure water. Simple in vitro test indicates that Hb-vesicles have the reduced inhibitory action of Hb to the EDRF-mediated vasorelaxation.

    DOI

  • グルタチオンによるHb小胞体のmetHb生成抑制

    横浜裕明, 清野由里子, 鄭 主恩, 酒井宏水, 武岡真司, 西出宏之, 土田英俊

    人工臓器   23 ( 3 ) 868 - 871  1994年

     概要を見る

    Hb小胞体中の高純度Hbのメト化抑制のために、α-tocopherol(α-Toc)とGlutathione(GSH)の使用を検討した。卵黄レシチンを膜成分として用いた系では、α-Toc添加により脂質の過酸化が抑制され、met-Hb生成速度は低下する。しかしDPPCなどの飽和型脂質を用いた系の方がmetHb生成速度は低くなる。<br>GSHはmetHbを還元する一方、酸素酸化過程で生じる活性酸素種が逆にmetHb生成を促進する。Hb濃度を高くして還元速度を高め、酸素分圧を低くしてGSHの酸素酸化を抑制することにより、GSHによるmetHb生成を効果的に抑制した。Hb溶液系で最適なGSH添加条件を明らかにし、これをHb小胞体に適用することによりmetHb生成速度をGSH未添加系の半分以下に低下させることができた。

    DOI CiNii

  • Hb小胞体のオリゴ糖修飾効果

    酒井宏水, 滝貞幹正, 鄭 主恩, 武岡真司, 土田英俊

    人工臓器   23 ( 3 ) 864 - 867  1994年

     概要を見る

    ヘモグロビン小胞体の二分子膜成分に合成glycolipidを導入し、オリゴ糖鎖で小胞体表面を修飾した。小胞体表面から水相に伸びたオリゴ糖鎖の排除体積効果のため、Ca2+(5mM)やデキストラン(平均分子量40,000)添加により惹起される小胞体の凝集を抑制することができた。更に凍結融解後も粒径分布は変化はなく、ヘモグロビンの漏出、酸素親和度の変化は殆ど認められなかった。従って合成glycolipidの導入により、凍結保存可能なヘモグロビン小胞体が調製できた。

    DOI CiNii

  • PURIFICATION OF CONCENTRATED HEMOGLOBIN USING ORGANIC-SOLVENT AND HEAT-TREATMENT

    H SAKAI, S TAKEOKA, H YOKOHAMA, Y SEINO, H NISHIDE, E TSUCHIDA

    PROTEIN EXPRESSION AND PURIFICATION   4 ( 6 ) 563 - 569  1993年12月

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  • CRYOPROTECTION OF SYNTHETIC GLYCOLIPIDS FOR PHOSPHOLIPID-VESICLES

    H SAKAI, M TAKISADA, S TAKEOKA, E TSUCHIDA

    CHEMISTRY LETTERS   1993 ( 11 ) 1891 - 1894  1993年11月

     概要を見る

    The synthetic glycolipid; N-hexadecylmaltopentaonamide (HDMPA), was introduced as a component of a phospholipid vesicle (phi ca. 100 nm) of 1,2-dipalmitoyl-sn-glycero-3-phosphorylcholine (DPPC) to modify the surface of the vesicle with oligosaccharide. After freeze-thawing, the size of the vesicles does not change, and the leakage of 5(6)-carboxyfluorescein encapsulated into the vesicles is suppressed, indicating that the glycolipid possesses a cryoprotective activity.

    DOI

  • SINTERED-TANTALUM ELECTRODE MODIFIED WITH POLYPYRROLE BY ELECTROPOLYMERIZATION

    YS PARK, T OHTA, S TAKEOKA, K YAMAMOTO, E TSUCHIDA

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   66 ( 8 ) 2449 - 2451  1993年08月

     概要を見る

    Polypyrrole (PPy) formation in the interior of a porous electrode by electropolymerization was considered to be impossible. When a concentrated pyrrole solution was soaked into a sintered-Ta electrode and electrolyzed in a pyrrole-free solution, PPy was formed in the interior. PPy occupied 70% of the inner space, and no defect was observed by SEM.

    DOI

  • 人工血液研究の最近の進歩

    土田英俊, 武岡真司

    最新医学   48 ( 7 ) 1069 - 1077  1993年07月

    CiNii

  • In situ formation of PPy/Ta2O5/Ta structure by electropolymerization and its electrical properties

    Young-Seo Park, Shinji Takeoka, Kimihisa Yamamoto, Eishun Tsuchida

    Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals   227 ( 1 ) 219 - 229  1993年04月  [査読有り]

     概要を見る

    Both PPy film and Ta2O5 layer are simultaneously formed on Ta-electrode by one process of electrical oxidation in an aqueous solution. Preparation of the structure (PPy/Ta2O5/Ta) can also takes place by the electrolysis using Ta-electrode on which PPy is formed previously by electropolymerization. Since PPy film obtained by the former method has higher electric conductivity (110 S/cm) and better adhesion than the later, (PPy/Ta2O5/Ta)structure formed simultaneously is confirmed better electrical properties as a capacitor. © 1993, Taylor &amp
    Francis Group, LLC. All rights reserved.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • Recent advancement of ion-conductive polymers

    S. Takeoka, H. Ohno, E. Tsuchida

    Polym. Adv. Technol.   4 ( 2-3 ) 53 - 73  1993年02月

    DOI

    Scopus

    106
    被引用数
    (Scopus)
  • Preparation conditions of human hemoglobin resicles covered with lipid membranes

    Takeoka, S, Sakai, H, Nishide, H, Tsuchida, E

    Artificial Organs Today   3 ( 3 ) 129 - 136  1993年

  • IN-SITU FORMATION OF PPY/TA2O5/TA STRUCTURE BY ELECTROPOLYMERIZATION AND ITS ELECTRICAL-PROPERTIES

    YS PARK, S TAKEOKA, K YAMAMOTO, E TSUCHIDA

    MOLECULAR CRYSTALS AND LIQUID CRYSTALS   227   219 - 229  1993年

     概要を見る

    Both PPy film and Ta2O5 layer are simultaneously formed on Ta-electrode by one process of electrical oxidation in an aqueous solution. Prepara tion of the structure (PPy/Ta2O5/Ta) can also takes place by the electrolysis using Ta-electrode on which PPy is formed previously by electropolymerization. Since PPy film obtained by the former method has higher electric conductivity (110 S/cm) and better adhesion than the later, (PPy/Ta2O5/Ta)structure formed simul taneously is confirmed better electrical properties as a capacitor.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • Oxidation of a PPy‐modified tantalum electrode

    Young‐Seo Park, Kimihisa Yamamoto, Shinji Takeoka, Tomoyuki Ohta, Eishun Tsuchida

    Polymers for Advanced Technologies   4 ( 5 ) 329 - 334  1993年

     概要を見る

    A tantalum electrode on which polypyrrole (PPy) had been previously formed by electropolymerization was galvanostatically electrolyzed in an aqueous solution of 0.01 wt% phosphoric acid. This process contains the irreversible oxidation of a PPy film, the decomposition of solvent, and the formation of Ta2O5 by the reaction of OH− coming through the PPy film, with Ta electrodes. A three layer‐structure (PPy/Ta2O5/Ta) was confirmed by electron spectroscopy for chemical analysis (ESCA). A PPy film containing CIO4− as dopant [PPy(CIO4−)] was significantly deteriorated in comparison with PPy(TsO−) at the electrolysis. Therefore, the (PPy(TsO−)/Ta2O5/Ta) system showed better electrical characteristics as a capacitor than the (PPy(CIO4−)/Ta2O5/Ta) system showed better electrical characteristics as a capacitor than the (PPy(ClO4−)/Ta2O5/Ta) system. Copyright © 1993 John Wiley &amp
    Sons, Ltd.

    DOI

    Scopus

    2
    被引用数
    (Scopus)
  • 脂質分子膜で被覆したHb小胞体の調製条件

    武岡真司, 酒井宏水, 西出宏之, 土田英俊

    人工臓器   22 ( 2 ) 566 - 569  1993年

     概要を見る

    脂質分子膜で包まれたHb小胞体の酸素輸送効率を向上させるため、少ない層数(n)の分子膜で高濃度Hb溶液を被覆した小胞体調製が課題となる。層数(小胞体粒径200nmφ)と小胞体内のHb濃度([Hb]in)を測定する方法を確立し、調製条件との関係を解析した。その結果、Hb濃度増大に伴って[Hb]inは向上し、低温調製(4℃)により層数は低下しHb内包効率([Hb]/[Lipid]比)は向上する。また、この系は電解質系であるため、系のpHやイオン強度(塩濃度)の影響を受ける。[Hb]/[Lipid]比は等電点付近(pI=7.0)で最も高くなり、イオン強度が高くなると低下する。

    DOI CiNii

  • オリゴ糖修飾ヘモグロビン小胞体の分散安定度

    大串 健, 鄭 主恩, 酒井宏水, 武岡真司, 土田英俊

    人工血液   2   97 - 101  1993年

  • INHIBITION EFFECT OF AGGREGATION OF PHOSPHOLIPID-VESICLES BY INCORPORATION OF GLYCOLIPIDS

    S TAKEOKA, H SAKAI, H OHNO, K YOSHIMURA, E TSUCHIDA

    JOURNAL OF COLLOID AND INTERFACE SCIENCE   152 ( 2 ) 351 - 358  1992年09月

    DOI

    Scopus

    8
    被引用数
    (Scopus)
  • INHIBITION OF INTERVESICULAR AGGREGATION OF PHOSPHOLIPID-VESICLES BY INCORPORATION OF DIALKYL OLIGOSACCHARIDE GLYCEROL

    S TAKEOKA, H SAKAI, M TAKISADA, E TSUCHIDA

    CHEMISTRY LETTERS   1992 ( 9 ) 1877 - 1880  1992年09月

     概要を見る

    1,2-Di-O-octadecyl-3-O-alpha(beta)-maltopentaosyl-rac-glycerol (DOMPG) was incorporated into lipid vesicles to modify the surface of the vesicles. The aggregation of small unilamellar vesicles below the gel-to-liquid crystalline phase transition temperature and the aggregation of negatively-charged vesicles by the addition of calcium ion were effectively inhibited.

    DOI

  • SIMULTANEOUS FORMATION OF A POLYPYRROLE FILM AND A TANTALUM OXIDE LAYER BY ELECTROCHEMICAL OXIDATION

    YS PARK, K YAMAMOTO, S TAKEOKA, E TSUCHIDA

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   65 ( 7 ) 1860 - 1865  1992年07月

     概要を見る

    Electropolymerization of pyrrole on tantalum (Ta) electrodes was carried out in Britton-Robinson buffer solutions containing 0.1 M (1 M=1 mol dm-3) potassium chloride (KCl) under galvanostatic conditions. A polypyrrole (PPy) film and a tantalum oxide (Ta2O5) layer are formed on a Ta electrode by one electrochemical oxidation process. The conditions of this simultaneous formation were investigated in respect with the current density, pyrrole concentration, pH, and total charge. Under certain conditions ([py]=0.5 M, pH=1.8, current density=3.5 mA cm-2, charge 1 C), a 5.6-mu-m thick PPy film was efficiently formed on a homogeneous 45 nm thick Ta2O5 layer.

    DOI

  • Formation of PPy/Ta2O5/Ta structure by electropolymerization

    Young‐Seo Park, Shinji Takeoka, Kimihisa Yamamoto, Eishun Tsuchida

    Polymers for Advanced Technologies   3 ( 7 ) 395 - 400  1992年  [査読有り]

     概要を見る

    Electropolymerization of pyrrole on tantalum (Ta) electrodes was carried out in buffer solutions (0.04 M phosphoric acid, 0.04 M acetic acid, 0.04 M boric acid and 0.2 M sodium hydroxide) containing 0.1 M sodium ptoluenesulfonate (TsONa) under galvanostatic conditions and it was found that a polypyrrole (PPy) and a tantalum oxide (Ta2O5) layer are formed on a Ta electrode by an electrochemical oxidation process. The conditions of this simultaneous formation were studied in respect to current density (id), pyrrole concentration ([Py]), pH and the amount of electricity. Under certain conditions ([Py] = 0.25 M, pH = 1.8, id = 10–20 mA cm−2, the amount of electricity = 1 C), 6–8 μm thick PPy films were efficiently formed on homogeneous 30–50 nm thick Ta2O5 layers. The PPy film showed a high electrical conductivity (110 s cm−1), adhered well and covered the Ta2O5 layer. The resulting PPy/Ta2O5/Ta system is therefore proved to have excellent properties as a capacitor. Copyright © 1992 John Wiley &amp
    Sons, Ltd.

    DOI

    Scopus

    3
    被引用数
    (Scopus)
  • INTERACTION BETWEEN POLYNUCLEAR AROMATIC-HYDROCARBONS AND SODIUM-ION IN POLY(OXYETHYLENE)

    S TAKEOKA, K HORIUCHI, E TSUCHIDA

    SOLID STATE IONICS   50 ( 1-2 ) 175 - 179  1992年01月

     概要を見る

    The ion-ion interaction of the ion pairs between radical anions of pi-conjugative molecules (polynuclear aromatic hydrocarbons, AR) such as anthracene, phenanthrene or naphthalene, and sodium ion in CH3(OCH2CH2)xOCH3 was evaluated from ionic conductivity measurement. The rate of ion-dissociation increased as either the number of (oxyethylene) unit(x) or the electron affinity of AR increased. This indicates that the continuous (oxyethylene) units are more favorable for ion-dissociation and a molecule having higher ability to become a radical anion shows higher rate of dissociation.

  • OXYGEN-TRANSPORT AND SOLUTION PROPERTIES OF POLYLIPID HB VESICLES (ARC)

    S TAKEOKA, E HASEGAWA, H NISHIDE, E TSUCHIDA, S SEKIGUCHI

    BIOMATERIALS ARTIFICIAL CELLS AND IMMOBILIZATION BIOTECHNOLOGY   20 ( 2-4 ) 399 - 404  1992年

     概要を見る

    Polymerized phospholipid vesicle encapsulating Hb (polylipid/Hb vesicle) was prepared from a mixture of unsaturated phospholipid, cholesterol and unsaturated fatty acid and polymerization by gamma-ray irradiation. The average radius of resulting vesicles was 203 +/- 39 nm and concentrated Hb (30 wt%) was efficiently encapsulated. gamma-Ray polymerization proceeds theoretically at low temperature (4-degrees-C). P50 and oxygen transporting efficiency were adjusted to 40 mmHg and 40%, respectively. Oncotic pressure and solution viscosity can be controlled to the same values as blood.

  • Encapsulation of Hb into unsaturated lipid vesicles and γ-ray polymerization

    Sakai, H, Takeoka, S, Yokohama, H, Nishide, H, Satoh, T

    Polym. Adv. Technol.   3 ( 7 ) 389 - 394  1992年

    DOI

    Scopus

    17
    被引用数
    (Scopus)
  • Preparation of dehydrated powder of hemoglobin vesicles

    Lin Wang, Shinji Takeoka, Eishun Tsuchida, Satoru Tokuyama, Takahiro Mashiko, Tadashi Satoh

    Polymers for Advanced Technologies   3 ( 1 ) 17 - 21  1992年

     概要を見る

    The carbonyl hemoglobin (CO‐Hb), which was used to prevent denaturation (metHb) during the preparation of samples, was encapsulated into lipid vesicles constituted from unsaturated phospholipid, cholesterol and unsaturated fatty acid. Unsaturated components were polymerized by γ‐irradiation to enhance the stability of bilayer membrane. An aqueous dispersion of resulting Hb vesicles was freeze‐dried in the presence of saccharides (50–200 mM) to obtain a dehydrated powder of Hb vesicles. Change in the vesicle size, the leakage of encapsulated Hb and the oxidation of Hb to metHb were not observed. Therefore, the long‐term storage of Hb vesicles can be realized as a dry powder. Copyright © 1992 John Wiley &amp
    Sons, Ltd.

    DOI

    Scopus

    11
    被引用数
    (Scopus)
  • A lithium secondary battery using a thin film of polymer electrolyte as a separator

    Tomoyuki Ohta, Shinji Takeoka, Eishun Tsuchida, Han Yu Feng, Zheng Sheng Fu, Yun Pu Wang

    Polymers for Advanced Technologies   3 ( 8 ) 433 - 436  1992年

     概要を見る

    Ion‐conductive polymer which shows an ionic conductivity (σi) of 1.4 × 10−4S/cm at 25°C when mixed with LiClO4 (molar ratio in Li/OE = 0.05) was used as a separator of electrodes in a lithium secondary battery. The effect of high ionic conductivity on the performance of the battery was studied. The polymer structure was $$ \\left[ {\\rm H}\\rlap{-} ({\\rm CH}_2 {\\rm CHR}\\rlap{-} )_{\\rm n} {\\rm H},{\\rm R} = - {\\rm CH}_2 ({\\rm OCH}_{\\rm 2} {\\rm CH}_{\\rm 2} )_6 {\\rm OCH}_3 \\right],$$ and the cathode was comprised of poly(1,3,4‐thiadiazole disulfide), graphite powder and the polymer electrolyte. The cell [(−)Li/polymer electrolyte/graphite–poly(disulfide) (+)] had an open circuit voltage (Voc) of 3.25 V, a plateau voltage of 2.75 V, a discharge density (id) of 0.05 mA/cm2 with the cathode utilization of 63%, and achieved over several tens of cycles at 25°C. Copyright © 1992 John Wiley &amp
    Sons, Ltd.

    DOI

    Scopus

    1
    被引用数
    (Scopus)
  • ELECTROPOLYMERIZATION OF PYRROLE ON A TANTALUM ELECTRODE

    K YAMAMOTO, YS PARK, S TAKEOKA, E TSUCHIDA

    JOURNAL OF ELECTROANALYTICAL CHEMISTRY   318 ( 1-2 ) 171 - 181  1991年11月

     概要を見る

    Electropolymerization of pyrrole was carried out on tantalum as a base metal electrode. The Ta electrode retards polymerization at lower pyrrole concentrations because of the formation of insulating Ta2O5. However, at high concentrations of pyrrole, the polymerization proceeds efficiently to yield a polypyrrole (PPy) film, similar to that on a Pt electrode. The PPy film on a Ta electrode shows the same electroactivity and electric conductivity as that on a Pt electrode. Electropolymerization on Ta is accompanied by a decrease in electrode area due to the formation of the Ta2O5, the behavior of which is the only difference from that on Pt.

    DOI

    Scopus

    14
    被引用数
    (Scopus)
  • 高分子イオン伝導体の設計とその応用

    武岡真司, 土田英俊

    化学   46 ( 10 ) 68 - 69  1991年10月

    CiNii

  • SODIUM-ION CONDUCTION OF PERFLUOROSULFONATE IONOMER POLY(OXYETHYLENE) COMPOSITE FILMS

    S TAKEOKA, K HORIUCHI, S YAMAGATA, E TSUCHIDA

    MACROMOLECULES   24 ( 8 ) 2003 - 2006  1991年04月

     概要を見る

    A composite film of Na+-form Nafion and diendoacetylated poly(oxyethylene) (MBAR(w) = 400) (POE400E) was cast from a dimethylformamide solution at 120-degrees-C. The ionic conductivity of this thin film was measured. The resulting film showed good flexibility, transparency, and no leakage of POE400E up to the POE incorporation of 55 wt%. At this composition, sodium ionic conductivity was 1.0 x 10(-6) S cm-1, which is relatively high as a single-ion conductor because of the high dissociation of the sodium perfluorosulfonate groups. The ionic conductivity increases with POE incorporation. This can be explained from a decrease in the glass transition temperature (T(g)) of POE regions and the connection of ion clusters swollen by POE.

    DOI

    Scopus

    14
    被引用数
    (Scopus)
  • POE Incorporation into Ionic Clusters of Ionomer and Ion-conduction Behaviors

    S. Takeoka, H. Sakai, H. Shin, T. Ohta, E. Tsuchida

    POLYMERS FOR ADVANCED TECHNOLOGIES   2 ( 2 ) 69 - 74  1991年04月

     概要を見る

    Poly(oxyethylene) (POE) was incorporated into the ionic clusters of ionomer, ethylene and methacrylic acid (7.2% neutralized with KOH) copolymer membrane. The changes of properties were studied from SAXS, DSC, IR and ionic conductivity. The IR study suggested that the coordinated structures in ionic clusters of the membrane were destroyed by POE incorporation, and also SAXS suggested that ionic clusters were swollen by POE incorporation. The ionic conductivity, a carrier being K+ in this system, increases from 10(-16) S/cm to 10(-9) S/cm at 30 degrees C by the incorporation of POE (20.5 wt%). On the other hand, a large amount of POE (63 wt%) could be incorporated into ionomer membrane by the esterification of methacrylic acid groups (93%) with POE. When LiClO4 was added, ionic conduction occurred in the phase-separated POE domain, which had a low glass transition temperature (-55.2 degrees C), showing an ionic conductivity 2.6 x 10(-6) S/cm at 25 degrees C.

    DOI

    Scopus

  • PHASE-SEPARATION OF POLYMERIZED MIXED LIPOSOMES - ANALYSIS OF RELEASE BEHAVIOR OF ENTRAPPED MOLECULES WITH SKELETONIZATION

    S TAKEOKA, H SAKAI, H OHNO, E TSUCHIDA

    MACROMOLECULES   24 ( 6 ) 1279 - 1283  1991年03月

     概要を見る

    The mixed liposomes, composed of a polymerizable lipid, 1,2-bis(2,4-octadecadienoyl)-sn-glycero-3-phosphorylcholine (DODPC), and nonpolymerizable membrane constituents, DPPC, cholesterol, and sodium didodecyl phosphate, were prepared by an extrusion method. After polymerization, nonpolymerizable constituents were removed to obtain the polymerized framework of the liposome (the skeletonized liposome). The release of small molecules from the skeletonized liposomes through resulting holes was analyzed. A 5(6)-carboxyfluorescein (CF) and saccharides with various molecular weights were applied as release molecules. The molecular weight of dextran, whose retention ratio in the skeletonized liposomes is 50%, relates to the apparent size of the holes, i.e., the apparent domain size of the phase separation of a polymerized mixed liposome. The size of the holes increases with an increase in the mole fraction of nonpolymerizable lipids. This also depends on the polymerization temperature and the structure of nonpolymerizable lipids.

    DOI

    Scopus

    11
    被引用数
    (Scopus)
  • Ion dissociation and conduction of Nafion/modified oligo(oxyethylene) composite films

    Yun Pu Wang, Han Yu Feng, Zheng Sheng Fu, Eishun Tsuchida, Shinji Takeoka, Tomoyuki Ohta

    Polymers for Advanced Technologies   2 ( 6 ) 295 - 299  1991年

     概要を見る

    In order to improve the ionic conductivity of solid polymer electrolyte by controlling ion(alkali metal ion)–dipole(ether oxygen) interaction, two kinds of modification were adopted on oligo(oxyethylene) (OOE). One is the capping of terminal hydroxyl groups of OOE with methyl or acetyl groups. The other is the replacement of the center ethylene group of OOE with methylene or propylene group. Ion–dipole interaction was analyzed by measuring the ion dissociation, ion conduction and Tg of Nafion/modified OOE composite films. The modification of the end groups was more effective than that of the center group in increasing ionic conductivity. The methyl group is superior to the acetyl group as the end group of OOE for lithium ion conduction. Copyright © 1991 John Wiley &amp
    Sons, Ltd.

    DOI

    Scopus

    5
    被引用数
    (Scopus)
  • DISSOCIATION AND CONDUCTION OF ALKALI-METAL ION IN NAFION CROWN-ETHER COMPOSITE FILMS

    S TAKEOKA, H SAKAI, E TSUCHIDA

    CHEMISTRY LETTERS   1990 ( 9 ) 1539 - 1542  1990年09月

    DOI

  • Synthesis, polymerization and cation conductive properties of (-carboxy)-oligo(oxyethylene) methacrylate

    S. Takeoka, Y. Maeda, E. Tsuchida, H. Ohno

    Polym. Adv. Technol.   1 ( 3-4 ) 201 - 205  1990年08月  [査読有り]

  • LARGER CATIONS CAN MOVE FASTER IN SOLID POLYMER ELECTROLYTES

    H OHNO, N KOBAYASHI, S TAKEOKA, H ISHIZAKA, E TSUCHIDA

    SOLID STATE IONICS   40-1   655 - 658  1990年08月

    DOI

    Scopus

    50
    被引用数
    (Scopus)
  • LIPOSOME FORMATION OF SELECTIVELY-POLYMERIZED DIENE-CONTAINING PHOSPHOLIPIDS AND THEIR POSTPOLYMERIZATION

    S TAKEOKA, H OHNO, H IWAI, E TSUCHIDA

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   28 ( 4 ) 717 - 730  1990年03月

    DOI

    Scopus

    8
    被引用数
    (Scopus)
  • POLYMERIZATION OF LIPOSOMES EVALUATED FROM MOLECULAR-WEIGHT DISTRIBUTION OF DIENE-TYPE PHOSPHOLIPID POLYMERS

    S TAKEOKA, N KIMURA, H OHNO, E TSUCHIDA

    POLYMER JOURNAL   22 ( 10 ) 867 - 874  1990年

    DOI

    Scopus

    6
    被引用数
    (Scopus)
  • 「エネルギー利用関連新素材」(IV) 高分子固体電解質と電池

    武岡真司, 土田英俊

    燃料協会誌   69 ( 1 ) 56 - 64  1990年01月

    DOI CiNii

  • CONTROL OF RELEASE OF ENCAPSULATED MOLECULES FROM POLYMERIZED MIXED LIPOSOMES INDUCED BY PHYSICAL OR CHEMICAL STIMULI

    S TAKEOKA, H OHNO, N HAYASHI, E TSUCHIDA

    JOURNAL OF CONTROLLED RELEASE   9 ( 2 ) 177 - 186  1989年07月

    DOI

    Scopus

    7
    被引用数
    (Scopus)
  • EFFECT OF PHASE-TRANSITION ON PHOTOSENSITIZED RADICAL POLYMERIZATION OF DIENE-CONTAINING LIPIDS AS LIPOSOMES .7.

    H OHNO, S TAKEOKA, H IWAI, E TSUCHIDA

    MACROMOLECULES   22 ( 1 ) 61 - 66  1989年01月

    DOI

    Scopus

    18
    被引用数
    (Scopus)
  • DIENE-CONTAINING LIPIDS AS PROBES FOR PHASE-TRANSITION BEHAVIOR OF LIPIDS IN LIPOSOMES

    S TAKEOKA, H IWAI, H OHNO, E TSUCHIDA

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   62 ( 1 ) 102 - 108  1989年01月

    DOI

  • STUDY ON THE PHASE-TRANSITION BEHAVIOR OF POLYMERIZED LIPOSOMES THROUGH THE INTERACTION OF DIENE-GROUPS IN THEIR ACYL CHAINS

    S TAKEOKA, H SAKAI, L WANG, H OHNO, E TSUCHIDA

    POLYMER JOURNAL   21 ( 8 ) 641 - 648  1989年

    DOI

    Scopus

    2
    被引用数
    (Scopus)
  • POLYMERIZATION OF DIENE-CONTAINING LIPIDS AS LIPOSOMES BY RADICAL INITIATORS .6. POLYMERIZATION OF 1,3-BIS(2,4-OCTADECADIENOYL)-RAC-GLYCERO-2-PHOSPHORYLCHOLINE

    S TAKEOKA, E HASEGAWA, H OHNO, E TSUCHIDA

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   61 ( 6 ) 2007 - 2012  1988年06月

    DOI

  • POLYMERIZATION OF DIENE-CONTAINING LIPIDS AS LIPOSOMES BY RADICAL INITIATORS .4. EFFECT OF LIPID PACKING ON THE POLYMERIZATION PROFILE

    H OHNO, S TAKEOKA, H IWAI, E TSUCHIDA

    MACROMOLECULES   21 ( 2 ) 319 - 322  1988年02月

    DOI

    Scopus

    17
    被引用数
    (Scopus)
  • POLYMERIZATION OF LIPOSOMES COMPOSED BY DIENE-CONTAINING LIPIDS BY RADICAL INITIATORS .2. POLYMERIZATION OF MONODIENE-TYPE LIPIDS AS LIPOSOMES

    H OHNO, S TAKEOKA, H IWAI, E TSUCHIDA

    JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY   25 ( 10 ) 2737 - 2746  1987年10月

    DOI

    Scopus

    19
    被引用数
    (Scopus)
  • POLYMERIZATION OF DIENE CONTAINING LIPIDS AS LIPOSOMES BY RADICAL INITIATORS .3. UNEQUIVALENT CHEMICAL ENVIRONMENT OF DIENE GROUPS IN 1-ACYL AND 2-ACYL CHAINS OF POLYMERIZABLE LIPIDS ANALYZED BY RADICAL POLYMERIZATION

    H OHNO, S TAKEOKA, E TSUCHIDA

    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN   60 ( 8 ) 2945 - 2951  1987年08月

    DOI

  • INCORPORATION OF FLUORESCENT-PROBES TO THE INNER AQUEOUS PHASE OF PREVIOUSLY POLYMERIZED LIPOSOMES

    H OHNO, S TAKEOKA, N HAYASHI, E TSUCHIDA

    MAKROMOLEKULARE CHEMIE-RAPID COMMUNICATIONS   8 ( 5 ) 215 - 218  1987年05月

    DOI

  • SKELETONIZED HYBRID LIPOSOMES

    H OHNO, S TAKEOKA, E TSUCHIDA

    POLYMER BULLETIN   14 ( 6 ) 487 - 490  1985年12月

  • Rheological properties of PEG-modified HB-vesicles (HBVS) and their oxygen transporting capacity in vivo

    Sakai H, Sou K, Takeoka S, Kobayashi K, Tsuchida E

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   227, 339-PMSE Part 2   U541 - U542

▼全件表示

書籍等出版物

  • Functional Polymer Films, Chapt 29 Fabrication, Properties, and Biomedical Applications of Nanosheets

    Toshinori Fujie, Yosuke Okamura, Shinji Takeoka

    WILEY−VCH  2011年 ISBN: 9783527321902

  • 遺伝子治療、DDS

    武岡真司

    生命・医療・福祉ハンドブック、早稲田大学生命・生体・福祉研究所編、コロナ社  2007年02月

  • 動く臓器としての血液に学ぶ -人工赤血球・人工血小板への挑戦-

    武岡 真司, 岡村 陽介, 阿閉 友保

    “ファイバー” スーパーバイオバイオメティクス 〜近未来の新技術創成〜 本宮 達也 監修, NTS  2006年10月

  • Hemoglobin-Vesicles as a Molecular Assembly: Characteristics of Preparation Process and Performances as Artificial Oxygen Carriers

    H. Sakai, K. Sou, S. Takeoka, K. Kobayashi, E. Tsuchida

    Blood Substitutes, Elsevier, Amsterdam  2006年

  • 血液疾患ハンドブック、人工血液の開発の現状と展望

    武岡真司

    再生つばさの会  2005年06月

  • 図解 高分子新素材のすべて、国武豊喜監修、人工赤血球の仕組み

    武岡真司

    工業調査会  2005年05月

  • Organ Microcirculation, Design and Modification of Nanoparticles for Blood Substitutes

    Takeoka,S

    Springer  2005年

  • Artificial Oxygen Carrier, Hemoglobin-Vesicles (HbV) as Artificial Oxygen Carriers

    Sakai, H, Sou, K, Takeoka, S, Kobayashi, K, Tsuchida, E

    Springer  2005年

  • 「医療用マテリアルと機能膜」,第5章人工赤血球

    酒井宏水, 宗慶太郎, 武岡真司, 小林紘一, 土田英俊

    (株)シーエムシー出版  2005年

  • 機能性脂質のフロンティア、2 リン脂質二分子膜小胞体を利用した赤血球代替物

    武岡真司

    シーエムシー出版  2004年12月

  • 最近の化学工学56 先端医療における化学工学 人工血液(赤血球、血小板)の最近の進歩

    武岡真司

    化学工業社  2004年12月

  • バイオロジクス−生物由来物質を用いた製品開発−

    武岡真司, 後藤洋子, 川上浩良

    高分子学会編  2004年09月

  • 周術期輸液の最前線、IV 酸素輸液の展望1)小胞体型人工赤血球の開発動向

    宮尾秀樹編, 武岡真司

    真興交易㈱医書出版部  2004年

  • 新訂版・表面科学の基礎と応用、第12節, 人工赤血球

    土田英俊, 武岡真司, 小松晃之, 酒井宏水

    エヌ・ティー・エス社  2004年

  • ぼくもノーベル賞をとるぞ!!

    高分子学会編著, 武岡真司ほ

    朝日出版社  2001年

  • バイオミメティックスハンドブック、酸素輸液としての人工赤血球(第7章(分泌と体内輸送系)第6節)

    長田義仁, 土田英俊, 酒井宏水, 武岡真司

    エヌ・ティー・エス社  2000年

  • Evaluation of the Oxygen Trasnporting Capability of Hemoglobin Vesicles "Blood Substitutes-Present and Future Perspectives" chapt.14

    Elsevier Science  1998年

  • Stabilized Hemoglobin Vesicles

    "Artificial Red Cells" John Wiley & Sons  1995年

  • Interpolymer Complexes and their Ion-Conduction

    "Macromolecular Complexes in Chemistry and Biology" Springer-Verlag  1994年

▼全件表示

Works(作品等)

  • Secretary, Program Committee, VII International Symposium on Blood Substitutes

  • Secretary, Executive Committee, 5th International Symposium on Polymers for Advanced Technologies(PAT)

  • Program Committee, Executive Committee, IX International Symposium on Blood Substitutes

  • Executive Committee, Internal Symposium on 21-COE Practical Nano-Chemistry

  • Program Committee, 13th Keio University International Symposia for Life Sciences and Medicine, Research and Development of Artificial Oxygen Carrier-Its Frontline-A Gateway to Diagnostic and Therapeutic Interventions

  • Organizing Committee, 14th Keio University International Symposia for Life Sciences and Medicine, Organ Microcirculation

▼全件表示

講演・口頭発表等

  • Antibiotic-loaded nanosheets for the treatment of gastrointestinal tissue defects

    発表年月: 2010年09月

  • Antibiotic-loaded nanosheets for the treatment of gastrointestinal tissue defects

    発表年月: 2010年08月

  • 機能性ナノ粒子やナノフィルムを用いたナノ医療へのアプローチ

    発表年月: 2010年06月

  • 高分子超薄膜( ナノシート) の物性とナノ絆創膏としての医療展開

    発表年月: 2010年06月

  • ナノシートの物性と医療応用

    発表年月: 2010年06月

  • 高分子超薄膜(ナノシート)の医療展開

    発表年月: 2010年05月

  • 高分子超薄膜(ナノシート)を用いた医療展開

    発表年月: 2010年04月

  • Introduction of Bio-molecular Assembly Science Lab.

    発表年月: 2010年03月

▼全件表示

共同研究・競争的資金等の研究課題

  • ADP封入ナノ粒子を血小板好中球複合体に作用させ凝固障害と炎症病態を制御する

    日本学術振興会  科学研究費助成事業

    研究期間:

    2022年04月
    -
    2025年03月
     

    萩沢 康介, 武岡 真司, 石田 治, 金子 恒樹, 木下 学, 照井 克生, 宮本 守員

  • ARDSモデルラットにおける短時間液体呼吸と新規薬物伝達システムの治療効果の検証

    日本学術振興会  科学研究費助成事業

    研究期間:

    2021年04月
    -
    2024年03月
     

    針井 則一, 武岡 真司, 垣内 健太, 宮坂 武寛, 森口 武史, 後藤 順子, 菅原 久徳, 高三野 淳一

     概要を見る

    完全液体換気(TLV; Total Liquid Ventilation)は、難治性の肺疾患である急性呼吸窮迫性症候群(ARDS; Acute Respiratory Distress Syndrome)に対する治療法として期待される。しかし従来TLV研究に用いられてきたパーフルオロカーボン類は、コスト・安全性・温室効果係数に課題があり、代替液を用いたTLVシステムの構築が求められる。そこで我々は、安価かつ安全な材料として酸素ファインバブル(微小気泡)を分散させたリン酸緩衝生理食塩水(FB分散水)を用いたTLVシステムの確立を目指している。これまでに、FB分散水を用いたTLVシステムの構築とLPSの気管内投与モデルに対するTLVがARDSの予防的治療法(発症前介入)として有効であることを確認した。
    今回我々は、敗血症を原疾患とするARDSモデルを作製し、ARDS発症後のモデルに対する我々のTLVシステムの有効性を検討した。今年度は、尾静脈よりLPSを投与することでARDSモデルを作製する実験を行った。先行研究を参考にして、LPSを2.5-10 mg/kgの範囲で単回投与・複数回投与・持続投与を検討した。しかし、ARDSの特徴である、①低酸素血症、②びまん性の炎症(両側浸潤影)、③心不全の否定、すべてを実証できるモデルを作製する条件を確立できなかった。LPS投与量が少ない場合、全身での炎症は惹起されるが肺障害の所見が確認できず、LPS投与量が多い場合、肺障害の所見が確認されるが多臓器不全が原因でTLV介入前に死亡した。本結果を受け先行研究を見直すと、ARDSモデルの多くの研究で血液の酸素化に関するデータがなく、炎症性サイトカインでのみ判断しており、ラットはLPS感受性が低く、また炎症からの回復が早いため、敗血症-ARDSを再現することが難しい可能性が示唆された。

  • Lab-on-a-chipによる細胞内デリバリーキャリアナノ粒子の創製

    日本学術振興会  科学研究費助成事業

    研究期間:

    2020年04月
    -
    2023年03月
     

    武岡 真司

     概要を見る

    優れた細胞内デリバリー能を持つキャリアナノ粒子は、薬物運搬システム(DDS)の開発のみならず、核酸医薬品やゲノム編集における遺伝子治療用キャリア、そしてワクチンの開発においても重要である。本計画では、Lab-on-a-chipデバイスを用いて、A.アミノ酸型脂質の合成、B.キャリアナノ粒子の調製、 C.キャリアナノ粒子による薬物の細胞内デリバリー評価 までのプロセスを連結させて、脂質や薬物の種類に応じたキャリアナノ粒子の最適化を多変量解析から行う。具体的には、Aでは、フローマイクロ反応デバイスにて脂質各部を連結させて得られるライブラリーに対して、Bのマイクロ流体デバイスを用いて薬物担持キャリアナノ粒子(薬物内包リポソームや核酸複合脂質ナノ粒子)を構築し、Cのマイクロ流体デバイスを用いてキャリアナノ粒子と細胞を混合し薬物や核酸の細胞内デリバリーをフローサイトメトリーや共焦点顕微鏡の画像解析から評価する。各プロセスについて重回帰分析から各条件の最適化を高効率に行うことで、多様な構造の脂質と組成や大きさの異なるナノ粒子の分散液に対して、その細胞導入効果 を一挙に評価することができる。2021年度は、A.確立したフローマイクロリアクタを用いた合成法が他の脂質に条件を調節すれば適用できることを確認し、スペーサー部を合成してライブラリーを充実させた。B.Herringbone構造のマイクロ流体デバイスでは、流路に目詰まりが頻度高く発生し、その除去や洗浄工程が煩雑になる課題が認められ、別構造・素材のマイクロ流体デバイスの探索を始めた。また、精製工程に供する中空糸モジュールを自作し、重回帰分析にて条件の最適化を行った。特に脂質収率は流路の前処理により向上すること見出した。C.細胞評価に関してはリポソーム添加後の細胞内カルシウム振動をAIによる画像解析する方法を想起した。

  • 縫合不全と術後癒着防止のための自己支持性高分子超薄膜(ナノシート)の開発

    日本学術振興会  科学研究費助成事業

    研究期間:

    2020年04月
    -
    2023年03月
     

    横田 一樹, 内田 広夫, 檜 顕成, 城田 千代栄, 武岡 真司, 藤枝 俊宣

     概要を見る

    2020年度までの研究で、LbL-EDC-PCL-silicaナノシートを吻合部に貼付することにより、4針縫合不全ラットを一週間以上生存させることに成功した。しかし、ヒト腸管に適用するためには、腸管内容物が漏出する可能性のある吻合部において、より高い腸管内圧に耐えうる接着性と強度が必要となる。脆弱なナノシートのみでは縫合部を確実に補強することは困難であると考えた。そこで、優れた適合性、生分解性に加え、体内の湿潤環境に耐えうる強度、腸管の蠕動運動に追従可能な柔軟性、および生体接着性を満たす新たな縫合部被覆材として、配向性架橋キトサンエアロゲルを想起し、改良と評価を行った。
    配向性架橋キトサンエアロゲルは、ジアルデヒド化キトサン(DACS)・キトサン混合溶液を調製後、一方向凍結乾燥法により作製した
    続いて、物性評価を行った。引張試験を実施し、ヤング率、引張強度および伸び率を算出した。最も高い強度を示すDACSの添加濃度を決定した。次に漏出防止能を評価した。切り出したブタ小腸表面に小切開を加え、エアロゲルを貼付し、耐圧試験を実施した。最も高い漏出防止能を示すエアロゲルの膜厚と貼付方向を決定した。この値は、ヒト小腸の最高内圧に匹敵していた。
    さらにISO-10993の規定に則った細胞毒性試験と、無傷のラット小腸に貼付し生体適合性を評価する動物実験を実施した。製法に改良を加え、生体安全性、生体適合性に優れた貼付材の作製に成功した。

  • 血小板代替リポソームによって炎症を制御して外傷性凝固障害を治療する

    日本学術振興会  科学研究費助成事業

    研究期間:

    2019年04月
    -
    2022年03月
     

    萩沢 康介, 武岡 真司, 石田 治, 宮崎 裕美, 木下 学, 佐藤 俊一

     概要を見る

    血小板代替リポソームであるH12-(ADP)-リポソームは受傷後に血小板が集積している部位への標的性をもっている。そこで放出されたADPは血小板膜上のP2Y12受容体を介して血小板機能を賦活し、ADPの一部はただちに細胞外で代謝されアデノシンとなり抗炎症作用を発揮する複合的な効果を有する。凝固障害の早期にH12-(ADP)-リポソームを投与することで、血小板からの炎症惹起物質の放出を抑え、血管内皮傷害を防止し、血小板機能を回復させることが示唆された。

  • 急性呼吸窮迫症候群ラットにおける短時間完全液体呼吸による炎症制御と肺胞障害の軽減

    日本学術振興会  科学研究費助成事業

    研究期間:

    2018年04月
    -
    2021年03月
     

    針井 則一, 武岡 真司, 松田 兼一, 宮坂 武寛, 森口 武史, 菅原 久徳, 高三野 淳一

     概要を見る

    急性呼吸窮迫症候群(ARDS)は致死率の高い疾患であるにも関わらず、未だ原因療法が確立されていない。我々は、マイクロ・ナノバブル分散酸素富化水による完全液体換気(肺洗浄法)がARDSの予防的治療法として有用であることを実証した。今回の結果は、発症前の介入であり発症後の治療効果を検証する必要があるが、肺傷害の原因物質を直接的に除去することが、炎症の鎮静化、救命率を向上に重要であることを示すことができた。

  • 神経活動電位・伝達物質を多重同時計測可能なナノ薄膜状ワイヤレスプローブの創製

    日本学術振興会  科学研究費助成事業

    研究期間:

    2018年04月
    -
    2021年03月
     

    藤枝 俊宣, 太田 宏之, 小林 正治, 武岡 真司

     概要を見る

    脳科学研究の進展に伴い、低侵襲的に脳組織に介入し種々の神経活動(電位・神経伝達物質)を計測可能な柔軟なプローブの開発が求められている。本研究では、柔軟性に優れる高分子薄膜の表面に配線をインクジェット印刷することで、単一神経細胞の活動電位を計測可能な針状神経電極を作製した。また、分子インプリント法を利用することで、神経伝達物質(例:ドーパミン)を電気化学的に選択的に補足可能なプローブも開発した。

  • 高齢者救急医療における貪食細胞機能強化に着目した薬剤耐性菌敗血症への新規治療戦略

    日本学術振興会  科学研究費助成事業

    研究期間:

    2018年04月
    -
    2021年03月
     

    木下 学, 守本 祐司, 中島 弘幸, 武岡 真司, 鈴木 博章, 小野 聡, 宮崎 裕美, 四ノ宮 成祥, 中島 正裕, 関 修司, 齋藤 大蔵

     概要を見る

    LPSプレコンディショニングは、大腸菌だけでなく緑膿菌やメチシリン耐性黄色ブドウ球菌の致死的感染でも劇的な救命効果があった。これはLPSプレコンディショニングで骨髄由来の単球系マクロファージが肝臓に集積し、強力な貪食殺菌能が発揮されたためであった。TLR4の特異的アゴニストであるMPLAのプレコンディショニングでも強力な貪食殺菌能が誘導できた。一方、本施策の開始判断となるcompromised hostでの貪食細胞の殺菌活性減弱を評価する抗菌活性評価チップの開発では、マウスの心理的ストレスモデルである水浸拘束での好中球の貪食殺菌活性の減弱を本チップで迅速に測定することに成功した。

  • バイオナノシートを活用した新しい眼科治療用デバイスの開発

    日本学術振興会  科学研究費助成事業

    研究期間:

    2017年04月
    -
    2020年03月
     

    柏木 賢治, 武岡 真司

     概要を見る

    生体分解性超菲薄膜(バイオナノシート)の眼科分野の活用について検討。 ①創口の閉鎖剤としての活用。角膜や強膜に創口を作成、その上に、バイオナノシートを貼付し、閉鎖促進性を確認。②drug delivery system(DDS)としての活用。眼圧下降剤の徐放システムとして有用性を検討。③難治性角膜上皮障害などの眼組織の損傷組織被覆材としての有用性の検討。④移植細胞の生着コントール材としての可能性の探求。⑤緑内障濾過手術補助剤としての活用。組織癒着防止作用薬剤の担持とバイオナノシートの低癒着性による組織癒着防止を利用した。

  • 止血能を有した救命蘇生用人工血液カクテルの開発

    日本学術振興会  科学研究費助成事業

    研究期間:

    2016年04月
    -
    2019年03月
     

    萩沢 康介, 武岡 真司, 鈴木 英紀, 酒井 宏水, 木下 学

     概要を見る

    家兎の循環血液量の2倍に相当する量を脱血し赤血球成分のみを返血することで、急性血小板減少による易出血性病態を作製した。そして肝臓に外傷性損傷を作り出血させ、Hbが6g/dl以下となる出血性ショックを誘導した。これに対してH12-(ADP)-liposomesとHbV、血漿成分を投与することでショック病態と凝固障害を改善させ、24時間以上の生存をもたらすことができた。
    これらの人工血液は長期保存が可能でプレホスピタルでの使用にも適しており、大量出血の早期から投与することで外傷による出血性ショックと凝固障害を合併した治療困難な病態の救命率向上が期待できる。

  • DDS型超分子デバイスを用いた光線力学療法による難治性小児がん根治への試み

    日本学術振興会  科学研究費助成事業

    研究期間:

    2016年04月
    -
    2018年03月
     

    田井中 貴久, 内田 広夫, 檜 顕成, 守本 祐司, 辻本 広紀, 城田 千代栄, 木下 学, 藤枝 俊宣, 武岡 真司

     概要を見る

    小児固形がんは浸潤・転移があっても集学的治療で腫瘍を完全除去できれば根治しうるが、実臨床においてそれは容易でない。しかし研究代表者らは、診断と治療の一期的施行(セラノスティクス)を可能とした新しいDDS(ドラッグデリバリーシステム)型薬剤である「ICGラクトソーム」を用いた蛍光診断および光温熱治療により、浸潤性神経芽腫モデル動物の腫瘍を縮退させることに成功した。小動物を用いた非臨床研究を進め、光温熱治療による腫瘍温度をモニタリングし43℃以上に光加温することで、ほぼ確実に腫瘍消褪効果を得た。また、動物実験によって、腫瘍への高い選択的集積性を証明した。

  • 蛍光ナノシートによる生物環境センサーの創製と専用デバイスの開発

    日本学術振興会  科学研究費助成事業

    研究期間:

    2016年04月
    -
    2018年03月
     

    武岡 真司, 藤枝 俊宜, 佐藤 裕崇, 染谷 大地

     概要を見る

    生物にとって快適な生存環境では、温湿度、酸素濃度、pHなどが適度に調節されているが、この保持には複数箇所で複数因子をリアルタイムで計測する煩雑で高価なシステムが必要となる。本研究では、対象表面に貼付できるナノシート型蛍光センサーと実用的な計測デバイスを開発することを目的としている。報告者は、温度・酸素用蛍光分子候補をナノシートに封入した温度・酸素用蛍光センサーに参照蛍光ナノシートと複合させたシステムとレシオ値の時間分解能が膜厚に影響を受けることに着目してpH用蛍光高分子を設計した。合成したpH用蛍光高分子と交互積層法、参照蛍光ナノシートを用いてナノシート型蛍光pHセンサーの構築に成功した。

  • バイオイメージングへの応用に向けたコロイド状メソポーラスシリカ粒子の外表面被覆

    日本学術振興会  科学研究費助成事業

    研究期間:

    2015年04月
    -
    2018年03月
     

    黒田 一幸, 下嶋 敦, 武岡 真司, 大庭 悠輝, 永田 晧也, 廣岡 奈緒子, 藤原 峰一

     概要を見る

    本研究課題ではコロイド状メソポーラスシリカナノ粒子(CMS)のバイオイメージング担体としての応用に向けて、CMS内部空間の精密制御法及びCMSへの温度応答性色素の封入法を開発した。細孔の鋳型となるミセルを膨潤させ、CMSの細孔径のみを4 nm - 8 nmの範囲で制御可能であった。またCMSに対しエテニレン架橋された有機シロキサンを外表面被覆することで、分散安定性の高い中空シロキサンナノ粒子が得られた。加えて、色素を導入したCMSに対し制御したpH条件下でアルコキシシランを添加することにより、内部空間での色素の温度感受性を維持しつつ粒子外表面のみを選択的に被覆することに成功した。

  • 急性呼吸窮迫症候群モデルラットにおける短時間完全液体呼吸の有用性

    日本学術振興会  科学研究費助成事業

    研究期間:

    2015年04月
    -
    2018年03月
     

    針井 則一, 武岡 真司, 松田 兼一, 森口 武史, 後藤 順子

     概要を見る

    急性呼吸窮迫症候群(acute respiratory distress syndrome, ARDS)に対する人工呼吸器療法は,あくまでも支持療法であり,ARDSによる肺胞の傷害を直接除去する治療は未だ確立されていない.我々は,マイクロ/ナノバブル分散酸素富化水(MNB液)による完全液体換気システムを応用した肺胞洗浄法を構築した.今回,ARDS の病態である肺胞の傷害を直接的に除去することで,炎症を鎮静化,救命率を向上させうる治療法を確立するために,1)液体換気条件の最適化,2)液体換気からガス換気への復帰試験,3)ARDSモデルラットの作製を実施した。

  • バイオナノシートを用いた新しい眼科ドラックデリバリーシステムの開発

    日本学術振興会  科学研究費助成事業

    研究期間:

    2014年04月
    -
    2017年03月
     

    柏木 賢治, 武岡 真司

     概要を見る

    以下のようなシート性状を持ったバイオナノシートを開発し、眼科応用の可能性について検討した。1.アニオン膜とカチオン膜の交互積層膜、2.ポリ乳酸を用いたバイオナノシート、3.上記2つのハイブリッド。これらのシートを用い眼組織への貼付、担持薬剤の放出とそのプロファイルを検討した。主な担持薬剤は、ラタノプロスト、マイトマイシンC、抗菌剤とし、眼圧下降、濾過手術の補助剤、創部閉鎖において有用性と安全性を検討した。
    その結果、担持薬の一定で長期な放出プロファイルを確認した。さらに濾過手術の成績を向上すること、バイオナノシートのみで角膜創部の閉鎖が得られることが明らかになった。

  • 衝撃波に起因するびまん性肺出血の病態解明と止血制御対策

    日本学術振興会  科学研究費助成事業

    研究期間:

    2013年04月
    -
    2016年03月
     

    萩沢 康介, 木下 学, 佐藤 俊一, 鈴木 英紀, 武岡 真司, 齋藤 大蔵, 半田 誠

     概要を見る

    爆発等の衝撃波による外傷では致死性の肺出血を合併することが多い。今回、ヒトのBlast Lung Injuryの病像に近似した致死性肺出血マウスモデルを用いて、血小板代替物であるH12-ADP-liposome投与による救命効果について検討したところ、H12-ADP-liposomeは、衝撃波による致死的肺出血の救命に有用である可能性が示唆され、その機序は止血効果とともに内封されたADPがアデノシンに代謝されて臓器保護効果を発揮することが明らかとなった。

  • 生物運動の制御基盤;化学力学フィードバックループ

    日本学術振興会  科学研究費助成事業

    研究期間:

    2010年04月
    -
    2016年03月
     

    石渡 信一, 武岡 真司, 鈴木 団, 宮崎 牧人, 板橋 岳志, 下山 勲, 福田 紀男, 島本 勇太, 小口 祐伴, 大山 廣太郎, 新谷 正嶺, 高木 潤, 佐藤 勝彦

     概要を見る

    本研究の第一の目標は、輸送・振動・分裂などの生物要素運動に必要な分子モーターや細胞骨格動態などが生み出す力が、要素運動の制御にフィードバックするという化学力学フィードバックループ(CMFループ)の存在を明らかにすることであった。その点、筋収縮自励振動(SPOC)現象における「ミオシンクロスブリッジ(CB)による力発生、筋フィラメントの滑り運動、フィラメント格子間隔の変化、CB形成確率の変化」というループの存在が強く示唆されたこと、外力パルス依存的に染色体分配のタイミングが調節されること、細胞質分裂に必要な収縮環の形成を人工細胞系で実現するなど、CMF ループの具体例を示すことができた。

  • 熱傷や消化管穿孔性腹膜炎に対する創傷被覆材としての新規高分子ナノシートの物性制御

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(基盤研究(B))

    研究期間:

    2009年
    -
    2011年
     

    武岡 真司, 合田 亘人

     概要を見る

    高分子超薄膜(ナノシート)は高い柔軟性と密着性を持ち、医用高分子を素材とすることで、新規な創傷被覆材として機能することが期待される。これまで研究代表者らは肺気胸モデル、胃切開モデルに対して術後の組織癒着の無い有用な創傷被覆材であることを実証してきた。本研究ではナノシートを機能化し、熱傷治療や消化管穿孔治療に向けた構造制御を行い、また、in vivo 試験による創傷被覆材としての有用性を実証した。

  • 生体内で長時間の酸素運搬効力を有するヘモグロビン小胞体の構築

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(基盤研究(C))

    研究期間:

    2006年
    -
    2007年
     

    武岡 真司, 武岡 真司

     概要を見る

    酸素を可逆的に結合するヘモグロビン(Hb)をリン脂質二分子膜小胞体(リポソーム)に内包したヘモグロビン小胞体(HbV)は、人工酸素運搬体として機能する。しかし、Hbは中心鉄が2価から3価に酸化(メト化)すると酸素結合能力を失う。この現象には、結合酸素に電子が一個移ることによるメト化(自動酸化)と、生じた活性酸素(過酸化水素)による更なるメト化が連動して起こっている。我々は、(メトHb/L-チロシン)系が過酸化水素を速やかに消去することを見出している。本研究では、L-チロシンを基質とするメトHbのペルオキシゲナーゼ活性を利用した過酸化水素消去系がメト化の抑制に効果的であることを確認し、この機構を解明した。また、この系を内水相に組み込んだHbVでは、過酸化水素を連続添加してもメトHbの生成は大幅に抑制されることから機能を確認できた。このHbVを20mL/kgラットに投与したところ、従来のHbVでは半分メト化する時間が14時間であったのに対し、44時間まで延長できた。更に、チロシン以外の14種類の候補基質に関してフェリルヘモグロビンラジカルと基質の反応速度の測定するスクリーニングにて、トリプトファンなどインドール環とカルボキシル基を持っ誘導体にてチロシンを上回る効果が見出された。他方、一酸化炭素化Hb(HbCO)は自動酸化によるメト化が起こらない。そして、循環血液中で少しずつHbO2に変換される現象を利用すれば、部分HbCOからなるHbVのメト化を抑制しつつ酸素運搬能力の持続が期待できる。本研究では、部分HbCOのメト化率の推移を測定したところ、CO化率に関わらず残りのHbO_2からのメト化速度はほぼ同じであったので、HbCOからのCOの脱離に伴って緩やかにメト化が起こる系の構築が示唆された。以上より、この二つのアプローチを組み合わせるとin vivoでHbVのメト化を効果的に抑制できると思われる。

  • 界面移行法による血中投与可能なナノ粒子のインテリジェント化

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(基盤研究(B))

    研究期間:

    2003年
    -
    2004年
     

    武岡 真司, 寺村 裕治

     概要を見る

    本研究では、人工赤血球や人工血小板の開発で集積してきた知見を利用して、これらナノ粒子の表面にレセプター蛋白質やペプチドあるいは糖鎖などのリガンドからなる認識部位を簡便な方法にて担持させてインテリジェント化させる方法を確立し、治療に有効なナノ粒子の構築を目指す。
    平成15年度では、2本鎖を持つアミノ酸型脂質を量合成し、これを固相合成法によりオリゴペプチドやオリゴ糖にコンジュゲイトする方法を検討し、2本鎖、4本鎖を持つポリエチレングリコール(PEG)脂質を得た。更に、片末端マレイミド基、もう片末端スクシンイミド基を持つPEGから、官能性PEG脂質を量合成した。また、ジスルフィド結合にてアルキル鎖を連結して膜貫通型としその末端にマレイミドPEGを結合したPEG脂質も得た。次に、生理活性物質であるリポポリサッカライド(LPS)を吸着させたリポソームについて、LPSを界面活性剤を用いて定量する方法の詳細な検討から、リポソームへLPSの界面移行現象に関する知見を得た。
    平成16年度では、これらのマレイミドPEG脂質をリポソームの表面に界面移行法によって導入し、そこで分子量の異なる蛋白質(Lactalbumin(分子量:14kDa)、rHSA(66.5kDa)、IgG(150kDa)、Ferritin(460kDa)、Thyrogrobulin(670kDa))を結合させて、リポソーム表面から遊離(界面移行)する速度を解析した。その結果、PEG脂質のアノキル鎖の数、長さ、そして蛋白質の分子量との間にきれいな相関が得られた。また、リポソーム表面に認識分子(やオリゴペプチド)を担持させ、さらにPEG鎖にて修飾すると、その認識機能はPEG鎖によってマスキングされる。しかし、PEG脂質が表面から遊離(界面移行)すると認識部位が露出して機能発現のスイッチングされる現象を明らかにした。以上の結果から、リポソーム表面を修飾するPEG脂質や蛋白質結合PEG脂質が遊離することにより体内動態が制御できる薬物運搬体が開発できた。

  • 微小循環機能恒常性を考慮した細胞型人工酸素運搬体の設計と開発

    科学研究費助成事業(慶應義塾大学)  科学研究費助成事業(基盤研究(B))

    研究期間:

    2001年
    -
    2002年
     

    末松 誠, 武岡 真司, 森崎 浩

     概要を見る

    肝臓・網内系は修飾ヘモグロビン(Hb)の主要な代謝コンパートメントである。ショック病態で救急救命に使用できる酸素運搬体はこれらの病態においても肝臓の恒常性を維持しつつ循環動態を改善できるスペックを持つ必要がある。本研究ではショック病態の肝臓ではヘムの分解代謝の動態が劇的に変動し、通常では考えられないような速度で肝臓に取り込まれたヘムがbilirubinに変換されることを明らかにした。これはストレス応答によりヘム分解酵素であるheme oxygenase (HO)-1が肝臓実質とKupffer cellで誘導されるためである。このような状況で肝臓に大量のHbが負荷されると肝臓の血流と胆汁を維持しているCOが捕捉、消去されてしまうため、血流低下や胆汁低下を来たすことが明らかになった。ヘモグロビン(Hb)を径250ミクロン大のliposomeに封入、表面をpolyethylene glycolで修飾して、血小板活性化能のない新規脂質で安定化させた試料を投与すると、そのような急速なヘムの分解や分解系酵素の誘導が抑制され、肝臓の血流や胆汁分泌が維持された。またビリルビンの表面修飾によりNOによるHbのメト化も部分的に抑制された。本研究ではHb-based oxygen carrierを体内投与した際に生じうる血管内皮細胞の機能変動をin vivoで評価する系としてNOのbioimaging技術を確立し、腸間膜における血管内皮細胞由来のNOのリソースについて重要な知見を得た。これまでNOのリソースは血管内皮と神経系と考えられてきたが、我々の得た知見は赤血球から供給されるリソースの存在を示唆するものであった。このような知見からHbを修飾した酸素運搬体ではこのような血流代償作用が期待できないことが示唆され、リポソーム型の場合であっても、血管内空間でリサイクルされるNOにどの程度の影響を与えるのかをさらに詳細に解析していく必要があると考えられた。

  • 細胞型酸素輸液の製造工程の確立

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(基盤研究(B))

    研究期間:

    2000年
    -
    2001年
     

    武岡 真司, 酒井 清孝, 西出 宏之, 土田 英俊, 酒井 宏水, 梅津 光生

     概要を見る

    本研究の推進により、酸素輸液(人工酸素運搬体、ヘモグロビン(Hb)小胞体)の大量製造のために製造工程の確立に成功した。成果内容は以下の通り。
    1.人工肺を用いたCO化、脱酸素化工程の確立:Hb溶液の一酸化炭素(CO)化と脱酸素化工程を内灌型、外灌型人工肺を用いて行ない、最適条件の設定と共にWilson-Plot法からガス交換効率を比較評価、大量精製工程を確立した。シリコン製中空子型ガス交換器を改良して耐久性、洗浄方法を評価した。
    2.電気化学的無酸素化法の確立:人工肺ではHb溶液のpO_210Torr以下は困難であるので、希薄水素/窒素混合ガス存在下電気化学的に溶存酸素を4電子還元して、水として完全除去する方法を確立した。
    3.連続液膜型配位子交換装置の評価:改良エバポレーターによる大面積液膜、シリコン製中空糸膜利用の配位子交換装置を試作、CO化Hb液膜にNaランプから強力可視光を照射、COを酸素に配位子交換する工程を評価、配位子交換の効率化に成功。
    4.アミノ酸を利用した新規脂質合成とその利用:ポリオキシエチレン結合アミノ脂質、負電荷アミノ脂質を新規に合成、簡便で安価な非リン型脂質類からなるHb小胞体の構築を検討し、表面修飾状態、調製条件(フィルター透過性、回収率)、Hb内包効率との関係について明らかにした。
    5.前処理工程の量産化と多段・連結式高圧押出装置の評価:混合脂質水和液の凍結融解・乾燥を行なう前処理法により押出法工程の所要時間を大幅に短縮した。また前処理工程の量産化のために、冷媒の温度、冷却速度、濃度、凍結融解の回数等と小胞体の粒径分布との相関を明らかにした。また、既存の押出装置の改良を行い、連結式高圧押出装置を試作評価して、効果的な造粒工程を改良できた。多段式装置と組合せた装置を発明し、造粒工程の量産化への目途を付けた。
    6.10L規模のHb小胞体製造装置の試作と評価:各工程の試作装置を接続し、10L規模のHb小胞体製造装置としての評価が進行中、この詳細データーから300L規模の製造プラントの詳細設計が進められている。

  • 一段階多電子過程を経由する分子変換系の確立

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(国際学術研究)

    研究期間:

    1996年
    -
    1998年
     

    土田 英俊, 小柳津 研一, 小松 晃之, 西出 宏之, ANSON Fred C., 宮武 健治, ANSON Fred C, ANSON F.C, ALLAN S.Hay, JURGEN Hinri, FRED C.Anson, 武岡 真司, 山元 公寿

     概要を見る

    高分子錯体が構成する特殊空間に取込ませた酸素の電子過程と、その反応制御に焦点を絞った解明から、これを酸素多電子還元が駆動する新しい分子変換過程として確立することを研究目的とする。
    本国際共同による成果は、4電子過程による酸素開裂機構の解明(Anson)、多電子過程による酸化重合反応の確立(Hay)、分子集合体雰囲気での多電子過程(Fuhrhop)などの確立を基礎として、これを多電子過程を活用した選択度高い分子変換系として定着させることができた。研究期間を通じ、双方の研究者が共同実験と討論により具体的な成果集積と的確な結論を把握、計31報の研究報文として印刷発表した。成果既要は以下の通りである。
    1.一段階多電子移動錯体の構造解明 同一電位で可逆な多電子移動を示す多核錯体(バナジウムサレン複核錯体*OV(salen)_2]^<X+>)を合成、各種物理化学計測から不均化平衡定数を決定、酸化状態の異なる錯体種の単離と結晶構造解析から配位構造と電子状態の相関を解明、一段階多電子過程生起の構造要件を普遍的知見として確立した。
    2.酸素4電子過程の構築 バナジウム複核錯体を活用し、酸素4電子還元に関与する4核のμ-oxo tetramer錯体(MOM-OO-MOM)の存在を実証、複核錯体それぞれが、連続的に2電子ずつ酸素分子に供与できる事実を確認。これが一般に4電子過程を経由する新しい酸素開裂法となりうることを実証した。
    3.多電子過程経由の分子変換系 室温下での新物質合成(ポリチオエーテル・ポリスルホニウムなど)を確立、これらの新しい光電子機能と材料としての可能性を具体化した。特にレーザーマススペクトルを用いて、生成高分子の精密構造(直鎖、環状、分岐など)を正確に把握した。
    4.高分子錯体の光電子過程 新しい多電子伝達系としてリポドポルフィリン、リピドプロトポルフィリンが形成する一次元多核錯体(ポリフィリンワイヤー)を対象に、顕微的方法(TEM,AFM,STM)および分光法(NMR,UV-vis.,Raman)を用いて微細構造を解析した。錯体構造と機能の相関解明に基づき有効な分子設計を具体化。
    5.新しい酸化重合反応の確立と具体化 芳香族チオエーテルを出発物質とする高分子量のポリ芳香族チオエーテル(Mw:20〜30万)を得る方法を展開、多電子反応を拡張して、酸化電位の高い有機基質の酸化活性化が可能となることを実証。また、スルホニウムを利用したポリヘテロアセンを得る方法を具体化。

  • 微小循環系動力学解析による赤血球代替物の前臨床評価試験

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(基盤研究(A))

    研究期間:

    1995年
    -
    1996年
     

    土田 英俊, 末松 誠, 石村 巽, 小林 紘一, 武岡 真司, 西出 宏之

     概要を見る

    本研究では、臨床試験前の赤血球代替物(A:全合成リピドヘム系、B:ヘモグロビン(Hb)小胞体)を対象とした微小循環系において、酸素運搬や溶液物性制御による組織への酸素分布変化を画像処理や定量解析から実施し、前臨床にある赤血球代替物の性能についての、最終評価を目的として実施されたものである。
    Hb小胞体アルブミン分散液による90%交換輸血試験では、血液ガス諸値及び各部組織酸素分圧が安定に推移、生存率100%として投与系の安全性も実証された。また、ポリオキシエチレン鎖(分子量5kD)にて表面修飾したHb小胞体の生理塩アルブミン溶液を用い、ハムスターの脱血交換を90%まで達成。経皮透視法による皮下組織の毛管の微小循環動態を顕微観測、血管径の変化、血流速度、有効血管密度、毛細管及び組織の酸素分布との相関などを測定、酸素運搬能力を評価した。その結果、ポリオキシエチレン鎖での表面修飾による凝集体形成の完全な防止効果が確認できた。またいわゆる、アセル型Hb(架橋Hb)に比較してセル型Hb(Hb小胞体)の優れた点と有効度も、体内動態観測から具体的に確認することができた。
    摘出肝臓の肝潅流試験から、組織酸素分圧に応じた細胞内NADHの蛍光消光挙動を画像処理システムを用いて観測、Hb小胞体分散液の潅流による組織への酸素運搬を微小循環と関連させた定量的観測も可能にすることができた。
    同様に全合成型リピドヘムについてin vitro、in vivo試験を行い、これらが赤血球と同等の酸素運搬能(血液としても同じ)を有することが確認できた。これらの成果は、今後本人工赤血球が臨床評価を終了して、具体的に発展するため必要不可欠であると考えられる。

  • ヘム誘導体の分子集合と動的電子過程に関する研究

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(一般研究(A))

    研究期間:

    1993年
    -
    1995年
     

    土田 英俊, 西出 宏之, 小松 晃之, 武岡 真司

     概要を見る

    両親媒性置換基を導入したテトラフェニルポルフィリン、及びプロトポルフィリン誘導体をリピドヘムとして10種類精密合成し、それらが水相系で形成する組織体の分子集合構造を解明した。電顕(TEM,Cryo-TEM,SEM)から形態(小胞体、紐状など)を観察。分光測定(UV-Vis.、蛍光)、特に励起子カップリングモデルによる計算から、ポルフィリン環の積層や配向など微細構造を決定した。リピドヘム集合体の形態形成の支配因子は、環境条件に加え錯体分子自身の親-疎水平衡とその立体構造に在ることが明確にされた。
    リピドテトラフェニルヘム誘導体の自己集合を利用した環境構築により、錯体部における内圏型電子移動の抑制が可能となり、生理条件下における安定な酸素錯体が実現した。特に特定の立体構造(置換基)を持たないリピドヘムでも、自己集合体形成により酸素錯体形成が初めて観測された。酸素配位素過程をレーザー閃光時間分解分光法を用いて動的解析を行った。第5配位座の軸塩基配位子の電子供与度調節が中心鉄の電子密度を制御して、酸素親和度を調節する結果と成る。更に、酸素配位座近傍の分子環境が酸素親和度に影響を与えることも定量的に明確にされた。
    4置換リピドプロトポルフィリンは、リン脂質小胞体の二分子膜中に自発的に取り込まれ、分子集合体(二分子膜)中で会合体を形成しない。リピドプロトヘムの酸素配位平衡は二分子膜のゲル-液晶相転移点に支配され、それが酸素配位速度定数の差に起因することが初めて解明された。
    更に、ポルフィリン集合体では分子充填状態により相互作用可能な分子が識別され、選択度の高い電子移動が三重項励起状態にあるポルフィリン中心から起こる電子移動過程として明らかにされた。
    以上、ポルフィリンの分子集合形成により電子過程や特定分子との相互作用の相違からこれを分子識別に利用できるので、新しい分子変換系構築に必要な知見と成り得ることが明らかに成った。

  • 「空気電池」に組み込む酸素選択透過膜の新合成と次世代一次電池としての試験

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(試験研究(B))

    研究期間:

    1993年
    -
    1995年
     

    西出 宏之, 金子 隆司, 鈴木 隆之, 武岡 真司, 土田 英俊

     概要を見る

    小型・計量・高エネルギー密度の次世代一次電池として期待される「空気電池」の実現には、酸素を選択透過し、窒素・水蒸気・二酸化炭素のバリヤ-となる高分子膜の創製が鍵となる。本研究では、空気電池に組み込む酸素選択透過膜を新しく合成し、一次電池としての電池特性を試験した。具体的には、空気から酸素の選択結合席としてコバルトポルフィリン(CoP)錯体を担持したフッ素や塩素系ポリマーまたは多孔ガラスを合成し、その薄膜の酸素透過性と窒素・水蒸気バリヤ-性を実証するとともに、これを組み込んだ半電池試験より電気化学特性を評価し、次世代型空気電池を構成する可能性と実用化に向けた今後の課題を明らかにすることを目的とした。
    (1)Mn触媒カーボン作用極、白金対極、水銀参照極、水酸化カリウム電解液からなる半電池セルを作成した。作用極片面に膜を貼り付け、定電位で酸素還元電流値を測定し膜透過酸素量とする方法論を確立した。CoP膜では酸素促進輸送が認められた。(2)ヘモグロビン液膜でも酸素透過の増大を定量把握できたが、液膜としてキャリヤ効果に限界があった。(3)細孔の内壁にCoPを導入した多孔膜をはじめて合成した。細孔内表面に酸素が選択的に結合し、拡散する表面拡散現象を実証した。酸素透過係数は10^<-6>を超え、大きな酸素流束が得られた。界面層内をホッピングして酸素が移行する過程を解析できた。(4)CoPを担持したフッ素樹脂被覆膜、塩化ビニリデンポリマー膜を作成し、これらの膜の水蒸気バリヤ性を確かめた。特に後者の膜では酸素促進因子が70を超えた。
    以上を総合して、酸素選択透過膜の設計合成手順をまとめた。

  • 両面の界面物性が相違する単分子膜の構成と電子移動

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(一般研究(C))

    研究期間:

    1993年
    -
    1994年
     

    武岡 真司

     概要を見る

    本研究では、界面物性が表裏両面で相違する単分子膜を基盤とする分子集合体の特徴を解明すると共に、例えばこの膜で特定蛋白質を内包した機能小胞体の実現を研究目的とする。
    疎水長鎖(二本足)両端に分極率の異なる基を結合させた両親媒性分子を水中に分散させ超音波照射により、粒径約120nmの単一分散径小胞体となる。高濃度のヘモグロビンと共に分散させて調製した小胞体では、粒径約100nmの単一分散のヘモグロビン小胞体が調製された。小胞体の総体積の測定値と小胞体系がすべて単分子膜構造と仮定した総体積の計算値の一致から単分子膜構造を確認した。また小胞体の分散状態は極めて安定であり、分子運動の測定や小胞体の内包物漏出測定からもこの膜が高い安定度を持つことが明らかにされた。
    NMRシフト試薬を用いた膜の表裏に分布するホスフォコリン基の割合の測定から、超音波照射した系では表層に76%が分布、興味深いことはヘモグロビンを小胞体に内包させた場合では95%以上となり、水相の環境相違が分子配向に影響していることも明示できた。その結果、小胞体構造は確実に安定化され、粒径、粘度、膜透過度など大きな問題を認めなかった。また、小胞体内のヘモグロビンの自動酸化が外相に膜を透過できない還元剤を用いて抑制されることから膜を隔てた電子移動に関する知見が得られた。
    リトコール酸の両端に長さを変化させた長鎖を結合させ、その先に親水基を結合させた両親媒性分子を新規に合成、二分子膜に導入した場合、界面物性と関連して高い分散安定度が確認された。更に単分子膜中央部の運動の抑制、及び相転移温度以上での親水部付近の分子運動性の増大が具体的に観測された。そして、膜自体の分子透過度は二分子膜よりも大きい結果から、リトコール酸の立体構造が膜を乱している可能性が高い。また、膜厚が分子鎖長よりも短い系にて大きく分子充填状態が乱れることが明らかとなった。

  • 赤血球代替物の非酵素的還元システムに関する研究

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(基盤研究(C))

  • 止血機能を有し、血管障害部位に特異的に集積する蛋白質高分子量体の設計

    科学研究費助成事業(慶應義塾大学)  科学研究費助成事業(萌芽的研究)

  • 新規な有機環状分子を用いたセシウムイオン凝集共沈除去システムの構築

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(挑戦的萌芽研究)

  • Compromised hostへの重度侵襲対策

    科学研究費助成事業(防衛医科大学校(医学教育部医学科進学課程及び専門課程、動物実験施設、共同利用研究)  科学研究費助成事業(基盤研究(B))

  • ナノシートとマイクロスキンを用いた重症熱傷救命のための治療開発研究

    科学研究費助成事業(防衛医科大学校(医学教育部医学科進学課程及び専門課程、動物実験施設、共同利用研究)  科学研究費助成事業(基盤研究(C))

  • 相分離貫通型ナノシートとナノディスクを利用する新規なナノフィルム製剤の創製

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(基盤研究(B))

  • 蛋白質結合高分子に関する調査

  • 有機導電材料に関する研究調査

  • 糖脂質の利用に関する研究調査

  • 微生物機能を利用した資源循環型水環境プロセスの構築

    文部科学省 

  • 人工臓器素材開発

    文部科学省 

▼全件表示

Misc

  • 力学的な階層構造を有するインクジェット印刷式神経電極の開発

    藤枝俊宣, 藤枝俊宣, 小久保奈々, 山岸健人, 荒毛将史, 武岡真司, 太田宏之

    日本バイオマテリアル学会大会予稿集(Web)   41st  2019年

    J-GLOBAL

  • エラストマーナノ薄膜のドライ転写を用いたMEMS光干渉型表面応力センサ

    高橋一浩, 澤田和明, 藤枝俊宣, 佐藤信孝, 武岡真司

    電気学会バイオ・マイクロシステム研究会資料   BMS-17 ( 19-31 ) 25‐29  2017年06月

    J-GLOBAL

  • 高分子ナノ薄膜とバイオ・エレクトロニクスの融合 (特集 生体に優しく,賢い未来材料"生体適合材料")

    藤枝 俊宣, 武岡 真司

    化学と工業 = Chemistry & chemical industry   70 ( 6 ) 494 - 496  2017年06月

    CiNii

  • インクジェット印刷による薄膜状微小電極の開発と神経活動電位のin vivo計測

    小久保奈々, 山岸健人, 武岡真司, 太田宏之, 藤枝俊宣, 藤枝俊宣

    日本バイオマテリアル学会大会予稿集(Web)   39th  2017年

    J-GLOBAL

  • AN ELASTOMER-BASED MEMS FABRY-PEROT INTERFEROMETER FOR PHYSICAL AND BIOLOGICAL SENSING BY DRY TRANSFER TECHNIQUE

    Kazuhiro Takahashi, Toshinori Fujie, Nobutaka Sato, Shinji Takeoka, Kazuaki Sawada

    30TH IEEE INTERNATIONAL CONFERENCE ON MICRO ELECTRO MECHANICAL SYSTEMS (MEMS 2017)     704 - 707  2017年  [査読有り]

     概要を見る

    We developed an elastomer-based Fabry-Perot interferometer with 120-1080 nm gap between a freestanding thin film and a substrate using dry transfer technique. A newly developed elastomeric nanosheet using a polystyrene-polybutadiene-polystyrene triblock copolymer (SBS) provides low Young's modulus of 40 MPa, large elastic strain of 40%, and high adhesiveness. A freestanding SBS nanosheet can be formed by dry transfer technique without vacuum and high temperature processes owing to the high adhesiveness of SBS nanosheet. A minimum gap length of 120 nm with an 80 mu m in diameter was achieved. With the pressure change, the freestanding membrane was found to deform with good adhesion between the dry transferred SBS and the substrate.

    DOI

  • Fabrication and evaluation of freestanding stretchable nanosheet for optical MEMS application

    Hayato Kumagai, Kazuaki Sawada, Kazuhiro Takahashi, Nobutaka Sato, Shinji Takeoka, Toshinori Fujie

    2016 INTERNATIONAL CONFERENCE ON OPTICAL MEMS AND NANOPHOTONICS (OMN)   2016-September  2016年09月  [査読有り]

     概要を見る

    © 2016 IEEE. We developed a stretchable freestanding ultra-thin sheet composed by poly(styrene-butadiene-styrene) (SBS) and evaluated its optomechanical properties. The freestanding SBS sheet with a thickness of 675 nm was formed above a through hole of a PDMS sheet. Deflection of the freestanding sheet with a size of 10.4 mm × 10.4 mm was found to be 50 nm by optical surface profiler. In evaluation of the sheet stretch measured by reflection spectra of a thin-film interference peak, SBS nanosheet revealed about 38% of elastic strain. This result demonstrated that the SBS nanosheet is stretchable even though its thickness is one order magnitude of thinner than PDMS.

    DOI

  • 生体組織に調和する高分子ナノシートの医療・ヘルスケアへの展開

    藤枝 俊宣, 山岸 健人, 武岡 真司

    化學工業   67 ( 2 ) 133 - 138  2016年02月

    CiNii

  • 人工血小板H12-(ADP)liposomesを用いた蘇生輸血の止血救命効果の評価

    多喜川真人, 萩沢康介, 木下学, 朝比奈はるか, 斎藤大蔵, 武岡真司

    人工血液   24 ( 1 )  2016年

    J-GLOBAL

  • 人工血小板H12-(ADP)liposomesを用いた蘇生輸血の機能評価

    多喜川真人, 萩沢康介, 木下学, 朝比奈はるか, 斎藤大蔵, 武岡真司

    高分子学会医用高分子シンポジウム講演要旨集   45th  2016年

    J-GLOBAL

  • リポソームの暗視野顕微鏡観察による脂質膜変形因子の探索

    稲葉岳彦, 岸本拓磨, 岸本拓磨, 田島拓也, 牧野麻美, 阿部充宏, 村手源英, 石塚玲子, 池田康夫, 武岡真司, 小林俊秀

    日本細胞生物学会大会要旨集   67th   161  2015年06月

    J-GLOBAL

  • 血小板:赤血球:血漿(1:1:1)蘇生輸血の新展開

    多喜川真人, 萩沢康介, 木下学, 朝比奈はるか, 斎藤大蔵, 武岡真司

    人工血液   23 ( 1 )  2015年

    J-GLOBAL

  • Intracellular Cu-free click reaction with a small chemical Ca2+ indicator

    Yoshiaki Takei, Atsushi Murata, Kento Yamagishi, Satoshi Arai, Hideki Nakamura, Takafumi Inoue, Shinji Takeoka

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   248  2014年08月

    研究発表ペーパー・要旨(国際会議)  

  • Fabrication and evaluation of free-standing microporous nanosheets made from poly (lactic acid)

    Shoichiro Suzuki, Toshinori Fujie, Hong Zhang, Shinji Takeoka

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   248  2014年08月

    研究発表ペーパー・要旨(国際会議)  

  • Development of fragmented nanosheets and patchwork coating as aqueous surface modifiers for biomedical applications

    Yosuke Okamura, Shinji Takeoka, Yu Nagase

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   248  2014年08月

    研究発表ペーパー・要旨(国際会議)  

  • PLCβ1のC末端は脂質膜の結合・変形活性をもつ

    稲葉岳彦, 岸本拓磨, 田島拓也, 牧野麻美, 阿部充宏, 村手源英, 石塚玲子, 池田康夫, 武岡真司, 小林俊秀

    脂質生化学研究   56   38 - 39  2014年05月

    J-GLOBAL

  • PD-1-3 人工赤血球や人工血小板などの血液代替物の開発とその将来展望(PD-1 パネルディスカッション(1)細胞・臓器移植における基礎的研究の最前線,第114回日本外科学会定期学術集会)

    木下 学, 萩沢 康介, 西川 可穂子, 柳川 錬平, 小野 聡, 齊藤 大蔵, 高瀬 凡平, 酒井 宏水, 半田 誠, 武岡 真司, 関 修司

    日本外科学会雑誌   115 ( 2 ) 168 - 168  2014年03月

    CiNii

  • 生細胞内クリック反応を利用したCa2+インジケーターの開発

    武井義明, 村田篤, 山岸健人, 新井敏, 中村秀樹, 井上貴文, 武岡真司

    日本化学会講演予稿集   94th ( 4 )  2014年

    J-GLOBAL

  • Fabrication methods of freestanding porous polymer thin films

    Hong Zhang, Natsuki Takamizawa, Shinji Takeoka

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   245  2013年04月

    研究発表ペーパー・要旨(国際会議)  

  • In vitro and in vivo evaluation of maleimide-modified liposome for drug delivery

    Tianshu Li, Shinji Takeoka

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   245  2013年04月

    研究発表ペーパー・要旨(国際会議)  

  • PS-246-1 血小板減少ウサギにおける外傷性肝出血に対するフィブリノーゲンγ鎖修飾アデノシンニリン酸含有リボソーム(H12-(ADP)-liposome)の救命効果(PS ポスターセッション,第113回日本外科学会定期学術集会)

    柳川 錬平, 木下 学, 西川 可穂子, 萩沢 康介, 庄野 聡, 半田 誠, 武岡 真司, 齋藤 大蔵, 妻鳥 元太郎

    日本外科学会雑誌   114 ( 2 ) 865 - 865  2013年03月

    CiNii

  • PS-044-6 抗生物質担持ナノシートを用いたIII度熱傷治療への有用性(PS-044 救急 感染症,第112回日本外科学会定期学術集会)

    齋藤 晃広, 木下 学, 宮崎 裕美, 藤枝 俊宣, 齋藤 大蔵, 武岡 真司

    日本外科学会雑誌   113 ( 2 ) 581 - 581  2012年03月

    CiNii

  • SF-108-1 コラーゲン・ポリ乳酸ナノシートを用いたメッシュの固定性に関する実験的検討(SF-108 サージカルフォーラム(108)腹壁・ヘルニア 基礎,第112回日本外科学会定期学術集会)

    藤野 啓一, 木下 学, 斉藤 晃広, 矢野 秀和, 西川 可穂子, 岩屋 啓一, 羽生田 博貴, 藤枝 俊宣, 武岡 真司, 斉藤 大蔵, 田中 祐司

    日本外科学会雑誌   113 ( 2 ) 432 - 432  2012年03月

    CiNii

  • SY-2-10 超極薄膜ナノシートの外科手術用創傷被覆材としての応用(SY-2 シンポジウム(2)外科領域における先端技術・治療の開発,第112回日本外科学会定期学術集会)

    木下 学, 藤枝 俊宣, 萩沢 康介, 大谷 直樹, 松谷 哲行, 宮崎 裕美, 斎藤 晃広, 藤野 啓一, 小野 聡, 齊藤 大蔵, 長谷 和夫, 関 修司, 武岡 真司

    日本外科学会雑誌   113 ( 2 ) 127 - 127  2012年03月

    CiNii

  • Preparation of nanoporous freestanding ultrathin films by polymer blend phase separation

    Hong Zhang, Shinji Takeoka

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   243  2012年03月

    研究発表ペーパー・要旨(国際会議)  

  • Therapeutic effects of tetracycline-loaded nanosheet for a deep burn-wound infection model

    Akihiro Saito, Hiromi Miyazaki, Toshinori Fujie, Shinya Ohtsubo, Manabu Kinoshita, Daizoh Saitoh, Shinji Takeoka

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   243  2012年03月

    研究発表ペーパー・要旨(国際会議)  

  • Arylazide introduced "turn-on" fluorescent probes for covalent labeling of a His-tagged protein

    Atsushi Murata, Satoshi Arai, Shinji Takeoka

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   243  2012年03月

    研究発表ペーパー・要旨(国際会議)  

  • Spatiotemporal Measurement of the Temperature Changes in Acidic Organelles with Fluorescent Nanothermometers

    Kotaro Oyama, Masao Takabayashi, Satoshi Arai, Shinji Takeoka, Shin'ichi Ishiwata, Madoka Suzuki

    BIOPHYSICAL JOURNAL   102 ( 3 ) 420A - 420A  2012年01月

    研究発表ペーパー・要旨(国際会議)  

  • 医療レギュラトリーサイエンスで育成すべき人材とは:TWInsの共同大学院における人材育成

    梅津光生, 有賀淳, 池田康夫, 伊関洋, 岩崎清隆, 笠貫宏, 武岡真司, 大和雅之

    日本生体医工学会大会プログラム・論文集(CD-ROM)   51st   ROMBUNNO.SY1-03-3  2012年

    J-GLOBAL

  • Synthetic Platelet H12-(ADP)liposomes Rescue Thrombocytopenic Rabbits from Non-Compressible Liver Bleeding

    M. Handa, K. NIshikawa, S. Takeoka, M. Kinoshita

    TRANSFUSION   51   6A - 6A  2011年09月

    研究発表ペーパー・要旨(国際会議)  

  • Thrombin-induced interaction between human platelets and fibrinogen gamma-chain dodecapeptide-modified liposomes as a synthetic platelet substitute

    H. Suzuki, Y. Okamura, Y. Ikeda, S. Takeoka, M. Handa

    JOURNAL OF THROMBOSIS AND HAEMOSTASIS   9   66 - 67  2011年07月

    研究発表ペーパー・要旨(国際会議)  

  • Role of counterions and hydrophobic spacers in amino acid based cationic assemblies and their transfection efficiency: A structure-activity investigation

    Satya Ranjan Sarker, Shinji Takeoka

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   241  2011年03月

    研究発表ペーパー・要旨(国際会議)  

  • カチオン性アミノ酸型脂質から成るリポソームによる神経細胞への遺伝子導入能評価

    青島由美子, SARKER S. R., 平川貴彬, 井上貴文, 武岡真司

    日本化学会講演予稿集   91st ( 3 )  2011年

    J-GLOBAL

  • Analysis of the interaction between cells and the different types of nanosheets

    Daisuke Niwa, Toshinobu Fujie, Thorsten Lang, Nobuhito Goda, Shinji Takeoka

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   239  2010年03月

    研究発表ペーパー・要旨(国際会議)  

  • 0202 人工血小板の微視的挙動と粘着メカニズムの解析(GS2:血球と微小循環)

    飛松 弘晃, PARAGON Antoine, 武岡 真司, 岡村 陽介, 谷下 一夫

    バイオエンジニアリング講演会講演論文集   2009 ( 22 ) 11 - 11  2010年01月

    CiNii

  • 高分子超薄膜(ナノシート)による下大静脈裂傷性止血の制御

    萩沢康介, 木下学, 藤枝俊宣, 斎藤晃広, 大谷直樹, 庄野聡, 武岡真司, 宮崎裕美, 小野聡, 斎藤大蔵, 北垣学, 松下芳太郎

    日本腹部救急医学会雑誌   30 ( 2 )  2010年

    J-GLOBAL

  • POLY 539-Biomedical application of polysaccharide nanosheet for tissue-defect repair

    Toshinori Fujie, Noriyuki Matsutani, Manabu Kinoshita, Yosuke Okamura, Akihiro Saito, Shinji Takeoka

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   238  2009年08月

    研究発表ペーパー・要旨(国際会議)  

  • ナノテクノロジーにより作成した超極薄膜ナノシートを用いた穿孔性腹膜炎時の穿孔部閉鎖治療

    木下学, 小野聡, 藤枝俊宣, 平木修一, 辻本広紀, 木村曉史, 下野浩貴, 岡村陽介, 宮崎裕美, 庄野聡, 武岡真司, 斎藤大蔵, 関修司

    日本腹部救急医学会雑誌   29 ( 2 ) 328  2009年02月

    J-GLOBAL

  • ORGN 626-Supramolecular assembly of porphyrin bearing barbituric acid based on complementary hydrogen bonding system

    Satoshi Arai, Shinji Takeoka

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   236  2008年08月

    研究発表ペーパー・要旨(国際会議)  

  • O-3-168 消化器外科でのナノテクノロジーの応用 : 消化管穿孔時の超薄膜ナノシートによる穿孔部修復(小腸・大腸 急性腹症2,一般演題(口演),第63回日本消化器外科学会総会)

    木下 学, 藤枝 俊宣, 小野 聡, 吉田 一路, 市倉 隆, 下野 浩貴, 岡村 陽介, 武岡 真司, 斎藤 大蔵, 関 修司

    日本消化器外科学会雑誌   41 ( 7 ) 1291 - 1291  2008年07月

    CiNii

  • DP-023-8 マウス穿孔性腹膜炎に対する超薄膜ナノシートを用いた被覆対策(第108回日本外科学会定期学術集会)

    藤枝 俊宣, 木下 学, 岡村 陽介, 松谷 哲行, 庄野 聡, 野上 弥志郎, 斎藤 大蔵, 武岡 真司

    日本外科学会雑誌   109 ( 2 ) 391 - 391  2008年04月

    CiNii

  • DP-060-1 胸膜欠損修復における超薄膜ナノシートの有用性の検討(第108回日本外科学会定期学術集会)

    松谷 哲行, 藤枝 俊宣, 木下 学, 岡村 陽介, 庄野 聡, 野上 弥志郎, 尾関 雄一, 武岡 真司, 前原 正明

    日本外科学会雑誌   109 ( 2 ) 463 - 463  2008年04月

    CiNii

  • COLL 162-Discrimination of hetero-surface for selective modification of the free-standing polysaccharide nanosheet in the utilization of structural color

    Toshinori Fujie, Yosuke Okamura, Shinji Takeoka

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   235  2008年04月

    研究発表ペーパー・要旨(国際会議)  

  • ORGN 172-Synthesis of porphyrins bearing uracyl groups and the analysis of their self-assembling behaviors

    Satoshi Arai, Shinji Takeoka

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   234  2007年08月

    研究発表ペーパー・要旨(国際会議)  

  • MEDI 116-Hemostatic effects of liposomes carrying fibrinogen gamma-chain dodecapeptide and encapsulating adenosine 5&apos;-diphosphate as a platelet substitute

    Yosuke Okamura, Ippei Maekawa, Makoto Handa, Yasuo Ikeda, Shinji Takeoka

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   234  2007年08月

    研究発表ペーパー・要旨(国際会議)  

  • POLY 612-Manipulation of free-standing polysaccharide nanosheets and their application on a nano-adhesive plaster

    Shinji Takeoka, Toshinori Fujie, Yosuke Okamura

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   234  2007年08月

    研究発表ペーパー・要旨(国際会議)  

  • 235 人工血小板の粘着メカニズムにおける力学的特性(OS2-6:循環系のバイオメカニクス,オーガナイズドセッション12:楽しめるバイオエンジニアリング)

    鈴木 健一, 土橋 直樹, 田村 典子, 後藤 信哉, 武岡 真司, 池田 康夫, 谷下 一夫

    バイオエンジニアリング講演会講演論文集   2006 ( 19 ) 294 - 295  2007年

    DOI CiNii

  • 人工酸素運搬体ヘモグロビン小胞体による固形腫瘍の酸素化

    泉陽太郎, 山本学, 竹内健, 渡辺真純, 堀之内宏久, 寺村裕治, 酒井宏水, 武岡真司, 土田英俊, 小林紘一

    日本外科学会雑誌   108  2007年

    J-GLOBAL

  • 人工酸素運搬体ヘモグロビン小胞体による固形腫瘍の酸素化

    泉陽太郎, 山本学, 竹内健, 渡辺真純, 堀之内宏久, 寺村裕治, 酒井宏水, 武岡真司, 土田英俊, 小林紘一

    人工臓器(日本人工臓器学会)   35 ( 2 )  2006年

    J-GLOBAL

  • 人工酸素運搬体ヘモグロビン小胞体による固形腫瘍の酸素化

    泉陽太郎, 山本学, 竹内健, 渡辺真純, 堀之内宏久, 寺村裕治, 酒井宏水, 武岡真司, 土田英俊, 小林紘一

    人工血液   14 ( 1 )  2006年

    J-GLOBAL

  • 接着分子を標的とした血小板代替物の創製

    岡村 陽介, 半田 誠, 武岡 真司, 鈴木 英紀, 村田 満, 池田 康夫

    日本血栓止血学会誌 = The Journal of Japanese Society on Thrombosis and Hemostasis   16 ( 5 ) 485 - 485  2005年10月

    CiNii

  • 血小板代替物 人工血小板の輸送と粘着のバイオメカニクス

    藤田 英輝, 鈴木 健一, 緒方 亜美, 田村 典子, 後藤 信哉, 武岡 真司, 池田 康夫, 谷下 一夫

    人工血液   13 ( 2 ) 72 - 72  2005年05月

  • 人工血小板の粘着及び流動時における微視的挙動の評価

    鈴木 健一, 藤田 英輝, 田村 典子, 後藤 信哉, 武岡 真司, 池田 康夫, 谷下 一夫

    人工血液   13 ( 2 ) 88 - 88  2005年05月

  • 人工酸素運搬体ヘモグロビン小胞体による固形腫ようの酸素化の試み

    泉陽太郎, 山本学, 竹内健, 渡辺真純, 堀之内宏久, 寺村裕治, 酒井宏水, 武岡真司, 土田英俊

    人工血液   13 ( 2 )  2005年

    J-GLOBAL

  • Hemostatic effects of fibrinogen-gamma chain dodecapeptide-conjugated polymerized albumin particles in vitro and in vivo.

    Y Okamura, N Watanabe, S Takeoka, H Suzuki, M Murata, Y Ikeda, M Handa

    BLOOD   104 ( 11 ) 58B - 58B  2004年11月

    研究発表ペーパー・要旨(国際会議)  

  • ドデカペプチド(H12)結合小胞体による血小板凝集作用

    前川一平, 寺村裕治, 岡村陽介, 武岡真司, 西出宏之, 土田英俊, 半田誠, 池田康夫

    日本化学会講演予稿集   84th ( 2 )  2004年

    J-GLOBAL

  • 高ずり速度下で発現する血小板代替物の血小板凝集協同効果

    岡村陽介, 寺村裕治, 武岡真司, 半田誠, 池田康夫, 土田英俊

    日本化学会講演予稿集   84th ( 2 )  2004年

    J-GLOBAL

  • ヘモグロビン小胞体のメト化抑制およびin vivo評価

    久保田恒平, 寺村裕治, 武岡真司, 西出宏之, 土田英俊

    日本化学会講演予稿集   84th ( 2 )  2004年

    J-GLOBAL

  • 高ずり速度下で発現する血小板代替物の血小板凝集協同効果

    岡村陽介, 寺村裕治, 武岡真司, 半田誠, 池田康夫, 土田英俊

    高分子学会予稿集(CD-ROM)   53 ( 1 )  2004年

    J-GLOBAL

  • ポリ乳酸微粒子界面への蛋白質結合法とその担持能

    大塚正宣, 岡村陽介, 寺村裕治, 武岡真司, 西出宏之

    高分子学会予稿集(CD-ROM)   53 ( 1 )  2004年

    J-GLOBAL

  • 血小板代替物の研究展開: 2. ずり速度の違いに対応できる微粒子系の構築

    岡村陽介, 寺村裕治, 武岡真司, 半田誠, 池田康夫, 土田英俊

    高分子学会予稿集   52 ( 14 )  2003年

    J-GLOBAL

  • 活性化血小板認識オリゴペプチド微粒子の機能評価

    岡村陽介, 寺村裕治, 武岡真司, 半田誠, 池田康夫, 土田英俊

    日本化学会講演予稿集   83rd ( 2 )  2003年

    J-GLOBAL

  • 活性化血小板認識オリゴペプチド微粒子の機能評価

    岡村陽介, 寺村裕治, 武岡真司, 半田誠, 池田康夫, 土田英俊

    高分子学会予稿集   52 ( 5 )  2003年

    J-GLOBAL

  • 血小板代替物の研究展開: 1. 分子集合系と重合系の粒子による機能の相違

    寺村裕治, 岡村陽介, 武岡真司, 土田英俊, 半田誠, 池田康夫

    高分子学会予稿集   52 ( 14 )  2003年

    J-GLOBAL

  • ビスマレイミドヘキサン架橋ヒト血清アルブミン二量体の特徴

    小黒有希子, 小松晃之, 寺村裕治, 武岡真司, 土田英俊

    日本化学会講演予稿集   83rd ( 2 )  2003年

    J-GLOBAL

  • 血小板代替物の設計とin vitro,in vivo評価

    武岡真司, 岡村陽介, 寺村裕治, 半田誠, 池田康夫, 土田英俊

    人工臓器(日本人工臓器学会)   32 ( 2 )  2003年

    J-GLOBAL

  • 活性化血小板認識オリゴペプチド微粒子の機能評価

    岡村陽介, 寺村裕治, 武岡真司, 半田誠, 池田康夫, 土田英俊

    人工臓器(日本人工臓器学会)   32 ( 2 )  2003年

    J-GLOBAL

  • カタラーゼ内包ヘモグロビン小胞体のin vivo評価

    寺村裕治, 金沢秀雄, 武岡真司, 土田英俊

    高分子学会予稿集   52 ( 5 )  2003年

    J-GLOBAL

  • カタラーゼ共封入ヘモグロビン小胞体の機能評価(1)

    金沢秀雄, 寺村裕治, 武岡真司, 西出宏之, 土田英俊

    日本化学会講演予稿集   83rd ( 2 )  2003年

    J-GLOBAL

  • ポリ乳酸微粒子表面へのタンパク質結合法

    大塚正宣, 岡村陽介, 寺村裕治, 武岡真司, 西出宏之

    高分子学会予稿集   52 ( 5 )  2003年

    J-GLOBAL

  • ドデカペプチド担持リン脂質小胞体の血小板認識能評価

    寺村裕治, 岡村陽介, 武岡真司, 土田英俊, 半田誠, 池田康夫

    人工臓器(日本人工臓器学会)   32 ( 2 )  2003年

    J-GLOBAL

  • カタラーゼ共封入ヘモグロビン小胞体の機能評価 (2)

    阿閉友保, 寺村裕治, 武岡真司, 西出宏之, 土田英俊

    日本化学会講演予稿集   83rd ( 2 )  2003年

    J-GLOBAL

  • カタラーゼ内包ヘモグロビン小胞体のin vivo評価

    金沢秀雄, 寺村裕治, 武岡真司, 土田英俊

    人工臓器(日本人工臓器学会)   32 ( 2 )  2003年

    J-GLOBAL

  • 血小板代替物としてのアルブミン重合体とリン脂質小胞体の認識反応制御

    寺村裕治, 岡村陽介, 武岡真司, 半田誠, 池田康夫, 土田英俊

    日本化学会講演予稿集   83rd ( 2 )  2003年

    J-GLOBAL

  • Role for P-selectin in platelet thrombus formation under flow.

    Y Okamura, N Watanabe, S Takeoka, Y Ikeda, M Handa

    BLOOD   100 ( 11 ) 258A - 259A  2002年11月

    研究発表ペーパー・要旨(国際会議)  

  • 人工血液の基礎研究と臨床への応用 人工赤血球 研究開発の現状と臨床応用

    堀之内 宏久, 小林 紘一, 渡辺 真純, 泉 陽太郎, 江口 圭介, 山本 学, 武岡 真司, 酒井 宏水, 小松 晃之, 土田 英俊

    人工臓器   31 ( 2 ) S94 - S94  2002年09月

  • 活性酸素に対するヘモグロビン小胞体の安定性

    寺村 裕治, 阿閉 友保, 武岡 真司, 土田 英俊

    人工血液   10 ( 3 ) 88 - 88  2002年08月

  • カタラーゼを内包したHb小胞体の活性酸素に対する安定性

    阿閉友保, 寺村裕治, 武岡真司, 西田宏之, 土田英俊

    人工臓器(日本人工臓器学会)   31 ( 2 )  2002年

    J-GLOBAL

  • 過酸化水素によるヘモグロビンのメト化機構と小胞体内包効果

    武岡真司, 阿閉友保, 寺村裕治, 西出宏之, 土田英俊, YONETANI T

    高分子学会予稿集   51 ( 5 )  2002年

    J-GLOBAL

  • 血小板代替物の担体としてのアルブミン重合体

    寺村裕治, 岡村陽介, 武岡真司, 土田英俊, 半田誠, 池田康夫

    人工臓器(日本人工臓器学会)   31 ( 2 )  2002年

    J-GLOBAL

  • 認識蛋白質の担体としてのアルブミン重合体とリン脂質小胞体の比較

    寺村裕治, 岡村陽介, 武岡真司, 西出宏之, 土田英俊, 池田康夫

    日本化学会講演予稿集   81st ( 2 )  2002年

    J-GLOBAL

  • リコンビナントGPIb α結合担体のvWFに対する流動状態下接着反応 性質の異なる担体での接着挙動

    岡村陽介, 寺村裕治, 武岡真司, 土田英俊, 村田満, 池田康夫, 半田誠

    日本血栓止血学会誌   13 ( 5 )  2002年

    J-GLOBAL

  • チオール類の二分子膜透過を利用するメトヘモグロビン小胞体の還元

    寺村裕治, 阿閉友保, 武岡真司, 西出宏之, 土田英俊

    高分子学会予稿集   51 ( 5 )  2002年

    J-GLOBAL

  • 人工血小板用担体としてのアルブミン重合体とリン脂質小胞体の機能比較

    岡村陽介, 寺村裕治, 武岡真司, 西出宏之, 土田英俊, 半田誠, 池田康夫

    高分子学会予稿集   51 ( 5 )  2002年

    J-GLOBAL

  • 還元剤の膜透過性を利用したメトヘモグロビン小胞体の還元

    阿閉友保, 寺村裕治, 武岡真司, 西出宏之, 土田英俊

    日本化学会講演予稿集   81st ( 1 )  2002年

    J-GLOBAL

  • 人工血小板用担体としてのアルブミン重合体

    武岡真司, 岡村陽介, 寺村裕治, 半田誠, 池田康夫

    日本輸血学会雑誌   48 ( 2 )  2002年

    J-GLOBAL

  • 細胞型・非細胞型ヘモグロビンと過酸化水素との相互作用とその影響

    武岡真司, 寺村裕治, YONETANI T, 土田英俊

    人工血液   9 ( 3 )  2001年

    J-GLOBAL

  • 細胞型・非細胞型ヘモグロビン由来酸素輸液と過酸化水素との相互作用とその影響

    武岡真司, 寺村裕治, 土田英俊, YONETANI T

    高分子学会予稿集   50 ( 5 )  2001年

    J-GLOBAL

  • 血小板膜蛋白質をアルブミン重合体あるいはリン脂質小胞体に結合させた血小板代替物の評価

    寺村裕治, 岡村陽介, 武岡真司, 池田康夫

    高分子学会予稿集   50 ( 14 )  2001年

    J-GLOBAL

  • 活性酸素種とヘモグロビンの相互作用と脂質二分子膜による内包効果

    武岡真司, 寺村裕治, 土田英俊

    高分子学会予稿集   50 ( 14 )  2001年

    J-GLOBAL

  • アルブミン重合体とリン脂質小胞体を担体とした血小板膜糖蛋白質rGPIbα結合体の機能比較

    寺村裕治, 岡村陽介, 武岡真司, 土田英俊, 村田満, 池田康夫

    高分子学会予稿集   50 ( 5 )  2001年

    J-GLOBAL

  • フィブリノーゲン結合アルブミン重合体の血小板代替物としての機能評価

    岡村陽介, 寺村裕治, 武岡真司, 土田英俊, 半田誠, 池田康夫

    高分子学会予稿集   50 ( 5 )  2001年

    J-GLOBAL

  • rGPIbα結合アルブミン重合体と小胞体の機能比較

    寺村裕治, 岡村陽介, 武岡真司, 半田誠, 池田康夫, 村田満, 土田英俊

    人工血液   9 ( 3 )  2001年

    J-GLOBAL

  • フィブリノーゲン結合アルブミン重合体の血小板代替物としての機能評価

    岡村陽介, 寺村裕治, 武岡真司, 半田誠, 池田康夫, 土田英俊

    人工血液   9 ( 3 )  2001年

    J-GLOBAL

  • ジスルフィド結合を利用した機能性蛋白質担持アルブミンマイクロスフェア

    寺村裕治, 武岡真司, 土田英俊

    日本化学会講演予稿集   78th ( 2 )  2000年

    J-GLOBAL

  • アルブミンマイクロスフェアを利用した血小板代替物モデル (2)

    寺村裕治, 大川春樹, 武岡真司, 土田英俊, 池田康夫

    人工血液   8 ( 3 )  2000年

    J-GLOBAL

  • 人工血小板として機能する微粒子の設計と機能評価

    武岡真司, 大川春樹, 寺村裕治, 土田英俊, 池田康夫

    高分子学会予稿集   49 ( 13 )  2000年

    J-GLOBAL

  • 認識蛋白質結合アルブミンマイクロスフェア

    武岡真司, 大川春樹, 寺村裕治, 土田英俊, 池田康夫

    高分子学会予稿集   49 ( 5 )  2000年

    J-GLOBAL

  • Proton conduction in sulfonated polyaromatics/polyoxyethylene composite.

    K Miyatake, S Takeoka, E Tsuchida

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   217   U489 - U489  1999年03月

    研究発表ペーパー・要旨(国際会議)  

  • Proton conduction in sulfonated polyaromatics/polyoxyethylene composite.

    K Miyatake, S Takeoka, E Tsuchida

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   217   U473 - U474  1999年03月

    研究発表ペーパー・要旨(国際会議)  

  • Lipidheme vesicles and hemoglobin vesicles as dioxygen infusion.

    T Komatsu, S Takeoka, H Sakai, E Tsuchida

    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY   217   U611 - U611  1999年03月

    研究発表ペーパー・要旨(国際会議)  

  • アルブミンマイクロスフェア利用の血小板代替物モデル

    武岡真司, 大川春樹, 寺村裕治, 池田康夫, 土田英俊

    人工血液   7 ( 3 )  1999年

    J-GLOBAL

  • 細胞型,非細胞型酸素輸液と微小循環挙動

    武岡真司, 湯浅美菜子, 浜崎将臣, 酒井宏水, 土田英俊, 末松誠, 石村巽

    高分子学会予稿集   47 ( 12 )  1998年

    J-GLOBAL

  • 微小循環研究の新展開 方法論と臨床応用 人工酸素運搬体と微小循環機能 ガス状血管拡張物質とヘモグロビンの相互作用

    末松誠, 武岡真司, 土田英俊, 石村巽

    医学のあゆみ   184 ( 10 )  1998年

    J-GLOBAL

  • 肝膜における一酸化炭素を介した類洞血管機能の制御

    末松 誠, 若林 良之, 武岡 真司, 合田 亘人, 土田 英俊, 石村 巽

    G.I.Research   5 ( 5 ) 625 - 625  1997年10月

    J-GLOBAL

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    「ミクロの技術で夢をかなえよ」r早稲田大学理工学部と慶應義塾大学医学部との共同研究によって開発された人工血液の紹介

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他学部・他研究科等兼任情報

  • 附属機関・学校   グローバルエデュケーションセンター

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  • 生体分子イメージング用ナノシートの構築

    2019年  

     概要を見る

    申請者は、機能性蛍光分子を固定したナノシートを用いて生体表面の温度やpHのレシオ型イメージングに成功した。本特定課題研究では、生体分子を蛍光イメージングとして捉えるために、フッ素系高分子インクでナノシート表面にパターンを印刷して自己展開する技術を確立した。また、アンモニアやドーパミンを電気化学的にセンシングする方針に変更して検討を行った。測定対象を呼気に含まれるアンモニアガスとしてPEDOT/PSS膜が吸着アンモニアガスを酸化する際の電流値の変化を測定すると共に、神経伝達物質であるドーパミンを対象としてドーパミンを鋳型に重合したPPy膜がドーパミンを選択的に酸化する際のシグナルの変化を測定している。

  • 脂質ライブラリー/マイクロ流路デバイスを用いたゲノム編集用ナノ粒子の開発

    2018年   李 天舒

     概要を見る

     リポソームは貪食細胞にエンドサイトーシスにて積極的に取り込まれる。報告者は、カチオン性アミノ酸型脂質のライブラリーを保有し、遺伝子やタンパク質の運搬体とした研究を推進してきた。その結果、脂質の構造(極性頭部、スペーサー長、アルキル鎖長、カウンターイオン)や、遺伝子やタンパク質との混合比や濃度によって、細胞への導入効率・遺伝子発現効率が異なることを示してきた。更には、細胞の種類によってもそれらの条件が異なることも示してきた。 ボン大学LIMESとの共同研究により、異なる構造のカチオン性アミノ酸型脂質からなるリポソームと免疫細胞との相互作用の分子機構を明らかにしてきた。その結果、ある特定の構造の脂質が特に自然免疫系の免疫細胞の賦活化ならびに獲得免疫系におけるアジュバント効果において、高い活性を示すことを初めて見出した。更に、あるカチオン性アミノ酸型脂質のアルキル鎖長が炭素数で2個異なるだけで、通常のエンドサイトーシス経路から膜融合の経路でリポソームが取り込まれることを見出した。膜融合は、標的細胞に対して、短時間に高効率でリポソームに担持させた薬物を細胞側に移行させることができる。 また、アニオン性アミノ酸型脂質リポソームにおいては、活性化された血小板との相互作用において、脂質の構造の相違がリポソームのζ電位の相違に繋がり、更に血小板凝集塊に取り込まれる効率が異なることも明らかにした。 この様な脂質構造と細胞における生理活性との相違をより高い効率でスクリーニングするために、混合脂質のエタノール溶液と担持させたい生体高分子を溶解させた水溶液とをマイクロ流路中で混合して、複合体ナノ粒子を構築し、限外ろ過によってエタノールやナノ粒子未担持の生体高分子を除去した後に、細胞との相互作用を評価する方法を検討している。

  • 微小環境イメージング用蛍光ナノシートの開発

    2018年   藤枝 俊宜

     概要を見る

    報告者は、ナノ粒子やナノシートに温度応答性の蛍光色素と標準用蛍光色素を利用したレシオ型ナノ温度計を開発し、細胞内エンドソームや筋組織の温度を蛍光顕微鏡で計測することに成功している。この場合、蛍光色素はナノシート内部に封入され温度以外の因子の影響は受けず、ナノシートは表面密着性が高いため高い時空間分解能にて表面温度を計測できた。そのデモンストレーションとして、カブトムシの飛翔筋組織に温度応答ナノシートと温度非感受性ナノシートを重ね合わせることによって、レシオ型な組織の温度イメージング像をリアルタイムに捉えることに成功した。また酸素応答性ポルフィリン誘導体を導入した薄膜型センサーをナノシート化した場合、酸素濃度の変化を感度良く捉えることもできている。この様に温度やガスのバイオイメージングでは、なるべく厚さが薄いナノシート程、時間分解能が高くなる。但し、感度を上げるためにはより広い領域で強度を稼ぐ必要があるために、空間分解能を下げざるを得なくなる。他方、pHの測定は、溶液中の濃度測定であるために、水溶性のポリアニオンに検出用蛍光物質を共有結合で固定し、ポリカチオンとの静電的なコンプレックスの形成(layer-by-layer 法)させた後熱架橋によって水中での安定化を確保することでpHセンサー部の構築に成功した。そのデモストレーションとしては昆虫の様な動物の組織のpH変化は時間軸が複雑であるために難易度が高い。そこで、植物に着目し植物の葉の組織にpH非感受性ナノシートと共に密着させて貼付し、高い塩化物イオンの水溶液に葉を曝すとシンポ―トによって塩化物イオンと共にプロトンを細胞内に取り込むことによって起こる、アポプラストpH変化をイメージング像として感度高く捉えることを示した。更に、膜厚はプロトン拡散に影響を及ぼすため薄膜化することで応答速度が速くなることを本研究で実証できた。

  • ナノシートのアジ化による可視化と分解挙動の解析

    2017年  

     概要を見る

    医用高分子の薄膜(ナノシート)は、創傷被覆用”ナノ絆創膏“として注目されている。本計画では、生分解性ナノシートの分解特性を、外見観察による形態や大きさの変化、顕微鏡観察による表面のラフネスの増大や膜厚の変化、構成分子量の低下などから解析した。37℃の生理食塩水中に自己支持状態で震盪させたところ、PDLLAナノシートでは3週間ごろからこより状になったが破断は見られず、7週間でも膜厚は変化しなかった。PLGA5050ナノシートでは膜表面が粗くなり日数と共に小さな孔が大きくなって4週間で破断につながった。酵素Proteinase K溶液による分解試験では、多孔質化と共にナノシートの膜厚の減少が認められ、その程度はPLGA&gt;PDLLA&gt;ポリカプロラクトンの順であった。

  • カチオン性リポソームの膜融合による生理活性高分子の細胞内送達システムの構築

    2017年   Tianshu Li

     概要を見る

    当研究室にて保有しているカチオン性アミノ酸型脂質ライブラリーを用いて、カチオン性アミノ酸型脂質リポソームを調製し、これをTHP-1細胞やマクロファージにアプライした。リポソームの粒子径やゼータ電位は殆ど相違しないにもかかわらず、脂質の分子構造が僅かに異なるだけで細胞との相互作用が大きく異なることが明らかとなった。主としてエンドサイトーシス機構で取り込まれるもの、膜融合機構で取り込まれるもの、殆ど細胞に取り込まれないものに分類された。膜融合機構で取り込まれるカチオン性リポソームはアニオン性のsiRNAやタンパク質など生理活性高分子を高い効率で運搬することが示唆され、従来にない生理活性高分子の細胞内運搬が見込まれる。

  • 生細胞内小器官の温度を計測するレシオ型分子温度計の創製

    2015年   井上 貴文

     概要を見る

    生細胞のミトコンドリアに集積して温度を計測するレシオ型蛍光プローブ(Mito-RTP)を開発した。本プローブは、温度感受性の無いNIR-rhodamine 101と温度感受性を示すRhodamine Bを共有結合させており、ミトコンドリア集積能を持つと共に蛍光強度比によって絶対温度が計測できる。HeLa細胞にMito-RTPを添加すると30分以内にミトコンドリアに集積し、培地温度を上昇させた際の温度依存性は-2.72%/℃であった。ミトコンドリアの脱共役剤を添加すると、約2.5 ℃の熱産生が引き起こされていた。

  • 細胞内小器官の温度を計測する新規な蛍光プローブの創製

    2014年   井上貴文

     概要を見る

    生細胞のミトコンドリア温度を測定するために、ミトコンドリアに局在するレシオ型温度応答性蛍光プローブを分子設計を行い、有機合成した。本プローブは温度応答性を示すローダミンBと温度に不感応なローダミン101のスペーサーにて結合させた構造であり、ローダミンBの蛍光強度/ローダミン101の蛍光強度の比は、温度上昇に比例して減少するので、濃度変化や焦点ブレに関係なく温度変化のみを検出できる。試験管レベルで検量線を作成したところ、2.72%/℃の温度感受性を有することが明らかとなった。また、本プローブは細胞に振り掛け約30分静置すると細胞膜を透過してミトコンドリアに集積する性質を持っているので、測定したいタイミングでミトコンドリアのみの温度を計測できる。また、測定条件では細胞毒性は認められなかった。脱共役剤(FCCP)をHeLa細胞の培地に添加したところ添加約5分後に有意な温度上昇が観測された。

  • 生細胞内クリックケミストリーによる生体関連分子イメージング法の開発

    2014年  

     概要を見る

    細胞膜透過性を有する無触媒クリック型蛍光色素FC-DBCO(Fluorescein-Conjugated DiBenzoCycloOctyne)を分子設計し、有機合成した。本プローブは蛍光分子であるフルオレセインの誘導体と無触媒クリック分子であるジベンゾシクロオクチンをカップリングした構造であり、細胞膜を自由に透過できる性質を持っている。従って、もし生細胞内にアジド基を有する標的分子があればそれと結合して蛍光標識するが、標的分子がない場合にはそのまま細胞を透過してしまい、培地の洗浄によりほぼ完全に細胞内から除去される。また、本実験条件では細胞毒性は認められなかった。N-アセチルマンノサミン誘導体(アジド化マンノース)とFC-DBCOを用いて生細胞内クリック反応を評価したところ、アジド化マンノースの細胞内動態(細胞質→酸性小胞体→ゴルジ体→細胞膜)を蛍光イメージングすることができ、生細胞内アジド基修飾分子の動態解析に対する本プローブの有用性を実証した。

  • バイオ医薬品運搬システム構築のための薬物担持リピッドナノシートの創製

    2011年  

     概要を見る

    研究代表者は、リン脂質二分子膜小胞体(リポソーム)を用いたドラッグデリバリーシステムの研究と開発を行っている。特に、リポソームに抗体を結合させたり、遺伝子を担持させる研究を進めてきた。一般にバイオ医薬品(抗体、酵素、遺伝子など)は高価であり、これをリポソームに内包させるためには内包効率を如何に向上させるかが課題となる。他方、研究代表者は、医用高分子からなるナノシートの開発に成功し、ナノ絆創膏などとして医療応用を目指している。本研究では、犠牲膜法でナノシートを構築する手法をヒントに、ポリビニルアルコール(PVA)の様な水溶性犠牲膜上に当研究室で保有しているカチオン性アミノ酸型脂質、ポリエチレングリコール結合脂質をコーティングしてナノシート(約5~10nm厚)を形成させ、そこに反対電荷のバイオ医薬品(アニオン性の成長因子、酵素、遺伝子)水溶液をキャストし、さらにカチオン性脂質のナノシート(約5~10nm厚)を形成させて3層構造を形成する方法を検討した。これを基板ごと水槽に浸漬させることで、犠牲膜であるPVA層が水に溶解し、3層構造の薬物担持リピッドナノシートが遊離する。リピッドナノシートは分子集合体であるため、水和と共に高速撹拌などでずり応力を加えると分子集合が再構築され、薬物を内包した二分子膜小胞体構造が得られ、ずり応力を撹拌速度やホモジナイザー、超音波照射によって強くするとそれに応じてリポソームの粒子径が小さく制御される。本法の利点は、アニオン性のバイオ医薬品の担持効率を究極に高めることであり、若干の漏出は溶解したPVAを限外濾過にて除去する際に除去できる。検討の結果、この方法の最大の課題はバイオ医薬品(例えば成長因子)のキャスト後の状態であった。スピンコート法で形成されたリピッドナノシートに成長因子をキャストした場合、凝集や相分離など不均一な状態で乾燥するとその上に平滑なリピッドナノシートを構築することができない。成長因子をスピンコートすることで平滑なナノシートを構築することができるものの、スピンコート時に相当量の成長因子が損失してし