Updated on 2024/02/28

写真a

 
SENTOKU, Mitsuru
 
Affiliation
Faculty of Science and Engineering, School of Advanced Science and Engineering
Job title
Research Associate

Research Experience

  • 2023.04
    -
    Now

    Waseda University   Faculty of Science and Engineering   Research Associate

Education Background

  • 2020.09
    -
    Now

    Waseda University   Graduate School of Advanced Science and Engineering   Pure and Applied Physics  

  • 2016.09
    -
    2020.08

    Waseda University   School of Advanced Science and Engineering   Physics Department  

Professional Memberships

  • 2020.06
    -
    Now

    Biophysical Society of Japan

Research Areas

  • Biophysics, chemical physics and soft matter physics

Awards

  • Miyabe Award

    2023.03   Master's Thesis

    Winner: Sentoku, Mitsuru

 

Papers

  • Importance of Spatial Arrangement of Cardiomyocyte Network for Precise and Stable On-Chip Predictive Cardiotoxicity Measurement

    Kazufumi Sakamoto, Suguru Matsumoto, Nanami Abe, Mitsuru Sentoku, Kenji Yasuda

    Micromachines   14 ( 4 ) 854 - 854  2023.04

     View Summary

    One of the advantages of human stem cell-derived cell-based preclinical screening is the reduction of the false negative/positive misjudgment of lead compounds for predicting their effectiveness and risks during the early stage of development. However, as the community effect of cells was neglected in the conventional single cell-based in vitro screening, the potential difference in results caused by the cell number and their spatial arrangement differences has not yet been sufficiently evaluated. Here, we have investigated the effect of the community size and spatial arrangement difference for cardiomyocyte network response against the proarrhythmic compounds from the viewpoint of in vitro cardiotoxicity. Using three different typical types of cell networks of cardiomyocytes, small cluster, large square sheet, and large closed-loop sheet were formed in shaped agarose microchambers fabricated on a multielectrode array chip simultaneously, and their responses were compared against the proarrhythmic compound, E-4031. The interspike intervals (ISIs) in large square sheets and closed-loop sheets were durable and maintained stable against E-4031 even at a high dose of 100 nM. In contrast, those in the small cluster, which fluctuated even without E-4031, acquired stable beating reflecting the antiarrhythmic efficacy of E-4031 from a 10 nM medium dose administration. The repolarization index, field potential duration (FPD), was prolonged in closed-loop sheets with 10 nM E-4031, even though small clusters and large sheets remained normal at this concentration. Moreover, FPDs of large sheets were the most durable against E-4031 among the three geometries of cardiomyocyte networks. The results showed the apparent spatial arrangement dependence on the stability of their interspike intervals, and FPD prolongation, indicating the importance of the geometry control of cell networks for representing the appropriate response of cardiomyocytes against the adequate amount of compounds for in vitro ion channel measurement.

    DOI

    Scopus

  • Dominant geometrical factors of collective cell migration in flexible 3D gelatin tube structures

    Mitsuru Sentoku, Kento Iida, Hiromichi Hashimoto, Kenji Yasuda

    Biophysical Reports   2 ( 3 )  2022.09

     View Summary

    Collective cell migration is a dynamic and interactive behavior of cell cohorts essential for diverse physiological developments in living organisms. Recent studies have revealed the importance of three-dimensional (3D) topographical confinements to regulate the migration modes of cell cohorts in tubular confinement. However, conventional in vitro assays fail to observe cells’ behavior in response to 3D structural changes, which is necessary for examining the geometric regulation factors of collective migration. Here, we introduce a newly developed assay for fabricating flexible 3D structures of capillary microtunnels to examine the behavior of vascular endothelial cells (ECs) as they progress through the successive transition across wide or narrow tube structures. The microtunnels with altered diameters were formed inside gelatin-gel blocks by photo-thermal etching with micrometer-sized spot heating of the focused infrared laser absorption. The ECs migrated and spread two-dimensionally on the inner surface of gelatin capillary microtunnels as a monolayer instead of filling the entire capillary. In the straight cylindrical topographical constraint, leading ECs exhibited no apparent diameter dependence for the maximum peak migration velocity. However, widening the diameter in the narrow-wide structures caused a decrease in migration velocity following in direct proportion to the diameter increase ratio, whereas narrowing the diameter in wide-narrow microtunnels increased the speed without obvious correlation between velocity change and diameter change. The results demonstrated the ability of the newly developed flexible 3D gelatin tube structures for collective cell migration, and the findings provide insights into the dominant geometric factor of the emerging migratory modes for endothelial migration as asymmetric fluid flow-like behavior in the borderless cylindrical cell sheets.

    DOI

    Scopus

  • In Situ Agarose Microfabrication Technology Using Joule Heating of Micro Ionic Current for On-Chip Cell Network Analysis

    Kenji Shimoda, Haruki Watanabe, Yoshitsune Hondo, Mitsuru Sentoku, Kazufumi Sakamoto, Kenji Yasuda

    Micromachines   13 ( 2 )  2022.02

     View Summary

    Agarose microfabrication technology is one of the micropatterning techniques of cells having advantages of simple and flexible real-time fabrication of three-dimensional confinement microstructures even during cell cultivation. However, the conventional photothermal etching procedure of focused infrared laser on thin agarose layer has several limitations, such as the undesired sudden change of etched width caused by the local change of absorbance of the bottom surface of cultivation plate, especially on the indium-tin-oxide (ITO) wiring on the multi-electrode array (MEA) cultivation chip. To overcome these limitations, we have developed a new agarose etching method exploiting the Joule heating of focused micro ionic current at the tip of the micrometer-sized capillary tube. When 75 V, 1 kHz AC voltage was applied to the tapered microcapillary tube, in which 1 M sodium ion buffer was filled, the formed micro ionic current at the open end of the microcapillary tube melted the thin agarose layer and formed stable 5 µm width microstructures regardless the ITO wiring, and the width was controlled by the change of applied voltage squared. We also found the importance of the higher frequency of applied AC voltage to form the stable microstructures and also minimize the fluctuation of melted width. The results indicate that the focused micro ionic current can create stable local spot heating in the medium buffer as the Joule heating of local ionic current and can perform the same quality of microfabrication as the focused infrared laser absorption procedure with a simple set-up of the system and several advantages.

    DOI

    Scopus

    1
    Citation
    (Scopus)
  • Stepwise neuronal network pattern formation in agarose gel during cultivation using non-destructive microneedle photothermal microfabrication

    Yuhei Tanaka, Haruki Watanabe, Kenji Shimoda, Kazufumi Sakamoto, Yoshitsune Hondo, Mitsuru Sentoku, Rikuto Sekine, Takahito Kikuchi, Kenji Yasuda

    Scientific Reports   11 ( 1 )  2021.12

     View Summary

    Conventional neuronal network pattern formation techniques cannot control the arrangement of axons and dendrites because network structures must be fixed before neurite differentiation. To overcome this limitation, we developed a non-destructive stepwise microfabrication technique that can be used to alter microchannels within agarose to guide neurites during elongation. Micropatterns were formed in thin agarose layer coating of a cultivation dish using the tip of a 0.7 μ m -diameter platinum-coated glass microneedle heated by a focused 1064-nm wavelength infrared laser, which has no absorbance of water. As the size of the heat source was 0.7 μ m , which is smaller than the laser wavelength, the temperature fell to 45 ∘C within a distance of 7.0 μ m from the edge of the etched agarose microchannel. We exploited the fast temperature decay property to guide cell-to-cell connection during neuronal network cultivation. The first neurite of a hippocampal cell from a microchamber was guided to a microchannel leading to the target neuron with stepwise etching of the micrometer resolution microchannel in the agarose layer, and the elongated neurites were not damaged by the heat of etching. The results indicate the potential of this new technique for fully direction-controlled on-chip neuronal network studies.

    DOI PubMed

    Scopus

    5
    Citation
    (Scopus)
  • Photothermal agarose microfabrication technology for collective cell migration analysis

    Mitsuru Sentoku, Hiromichi Hashimoto, Kento Iida, Masaharu Endo, Kenji Yasuda

    Micromachines   12 ( 9 )  2021.09

     View Summary

    Agarose photothermal microfabrication technology is one of the micropatterning techniques that has the advantage of simple and flexible real-time fabrication even during the cultivation of cells. To examine the ability and limitation of the agarose microstructures, we investigated the collective epithelial cell migration behavior in two-dimensional agarose confined structures. Agarose microchannels from 10 to 211 micrometer width were fabricated with a spot heating of a focused 1480 nm wavelength infrared laser to the thin agarose layer coated on the cultivation dish after the cells occupied the reservoir. The collective cell migration velocity maintained constant regardless of their extension distance, whereas the width dependency of those velocities was maximized around 30 micrometer width and decreased both in the narrower and wider microchannels. The single-cell tracking revealed that the decrease of velocity in the narrower width was caused by the apparent increase of aspect ratio of cell shape (up to 8.9). In contrast, the decrease in the wider channels was mainly caused by the increase of the random walk-like behavior of component cells. The results confirmed the advantages of this method: (1) flexible fabrication without any pre-designing, (2) modification even during cultivation, and (3) the cells were confined in the agarose geometry.

    DOI

    Scopus

    3
    Citation
    (Scopus)
  • On-chip multiple particle velocity and size measurement using single-shot two-wavelength differential image analysis

    Shuya Sawa, Mitsuru Sentoku, Kenji Yasuda

    Micromachines   11 ( 11 ) 1 - 15  2020.11

     View Summary

    Precise and quick measurement of samples’ flow velocities is essential for cell sorting timing control and reconstruction of acquired image-analyzed data. We developed a simple technique for the single-shot measurement of flow velocities of particles simultaneously in a microfluidic pathway. The speed was calculated from the difference in the particles’ elongation in an acquired image that appeared when two wavelengths of light with different irradiation times were applied. We ran microparticles through an imaging flow cytometer and irradiated two wavelengths of light with different irradiation times simultaneously to those particles. The mixture of the two wavelength transmitted lights was divided into two wavelengths, and the images of the same microparticles for each wavelength were acquired in a single shot. We estimated the velocity from the difference of its elongation divided by the difference of irradiation time by comparing these two images. The distribution of polystyrene beads’ velocity was parabolic and highest at the center of the flow channel, consistent with the expected velocity distribution of the laminar flow. Applying the calculated velocity, we also restored the accurate shapes and cross-sectional areas of particles in the images, indicating this simple method for improving of imaging flow cytometry and cell sorter for diagnostic screening of circulating tumor cells.

    DOI

    Scopus

    1
    Citation
    (Scopus)

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Presentations

  • Disappearance and Regeneration of Two-Dimensional Sheets of Collective Cell in Three-Dimensional Lumen Structures.

    Wataru Hanamoto, Mitsuru Sentoku, Miki Takei, Masaharu Endo, Kaito Asahi, Kenji Yasuda

    The 60th Annual Meeting of the Biophysical Society of Japan 

    Presentation date: 2022.09

    Event date:
    2022.09
     
     
  • Measuring the fluid-like behavior of collective cell migration in two-dimensional restricted structures.

    Miki Takei, Masaharu Endo, Mitsuru Sentoku, Wataru Hanamoto, Kenji Yasuda

    The 60th Annual Meeting of the Biophysical Society of Japan 

    Presentation date: 2022.09

    Event date:
    2022.09
     
     
  • Probing the influence of geometrical constraints on collective cell dynamics in diameter-varying 3D gelatin tube structures

    Mitsuru Sentoku, Kenji Yasuda

    The 60th Annual Meeting of the Biophysical Society of Japan 

    Presentation date: 2022.09

    Event date:
    2022.09
     
     
  • Application of photothermal agarose microfabrication technology for spatiotemporal analysis of collective cell migration

    The 59th Annual Meeting of the Biophysical Society of Japan 

    Presentation date: 2021.11

    Event date:
    2021.11
     
     
  • Effect of sudden change of confined environment in collective cell migration of epithelial cells.

    Masaharu Endo, Mitsuru Sentoku, Kenji Yasuda

    The 59th Annual Meeting of the Biophysical Society of Japan 

    Presentation date: 2021.11

    Event date:
    2021.11
     
     
  • Velocity split after passing through the wide-narrow-wide capillary tube caused by short-term memory in collective cell migration

    Mitsuru Sentoku, Hiromichi Hashimoto, Kento Iida, Masao Odaka, Akihiro Hattori, Kenji Yasuda

    The 58th Annual Meeting of the Biophysical Society of Japan 

    Presentation date: 2020.09

    Event date:
    2020.09
     
     
  • Width-dependent concave velocity distribution in collective migration is explained by two fluid-like behavior rules.

    Hiromichi Hashimoto, Mitsuru Sentoku, Syun Koide, Kento Iida, Masao Odaka, Akihiro Hattori, Kenji Yasuda

    The 58th Annual Meeting of the Biophysical Society of Japan 

    Presentation date: 2020.09

    Event date:
    2020.09
     
     
  • Measurement of the temporal rotation change of individual cells’ trajectory in collective cell migration in agarose microchannels.

    Shun Koide, Mitsuru Sentoku, Kento Iida, Hiromichi Hashimoto, Masao Odaka, Akihiro Hattori, Kenji Yasuda

    The 58th Annual Meeting of the Biophysical Society of Japan 

    Presentation date: 2020.09

    Event date:
    2020.09
     
     

▼display all

 

Internal Special Research Projects

  • Elucidating the influence of geometrical constraints on the collective cells' order regulation mechanism

    2023  

     View Summary

      The self-organization of adhesive cells give rise to spontaneous and orderly behaviors, such as directional movement and leader-follower like dynamics, that play a fundamental role in initiating various pathophysiological events in a life system. Despite having abundant research surrounding these emergent properties of the cells, however, the intricate cross interplay between multi-scaling biomolecules obscures understanding of how cells can perform various events at designated time and location under restricted environment. In this research subject, I focused on the question regarding how cells respond to changes in environmental cues by spontaneously regulating their ordering states, as events where the boundary structures change over time are ubiquitous during morphogenesis and wound healing. Utilizing the novel agarose microfabrication assay to generate gel topographical structures to confine cells, the interaction between the cells and the physical environment was examined. First, by analyzing the migration of cells having only front-rear interactions inside the single-cell width junction, it was revealed that endothelial cell lines simply filled the branches while epithelial cells had tendency of following the neighboring cells, with 2-3 consecutive cells having the highest frequency. To further examine how such cell innate interactions influence the collective cell behaviors, an analysis of collective migration was conducted inside confinements where the size of the boundary sequentially changes. As a result, branching and reassembling the cells migrating in cohort induced inhomogeneity in the dynamics and morphology of the cells at different sections of the confinement, despite conserving the overall geometrical dimensions of the micropattern. Lastly, the research also revealed that cells spontaneously adjust their dynamics inside confinements where the micropattern narrows, followed by an expansion back to its original width. The changes in velocity induced by altering the topography were not in accordance with passive matter models which suggest that the dynamics were limited by the contribution of cell innate properties such as morphology and retention of environmental information. Collectively, these results provide clues to unraveling the mechanism of how each cell comprising the assembly adjust their dynamics and local ordering states appropriately in response to changes in the boundary of the physical environment for maintaining proper function of the life system. These obtained results were presented in 1 local and 1 global academic conference held in USA, and a paper is currently being prepared to be published in academic journal.