Details of the Researcher

PHOTO

Keisuke Oku
Section
Advanced Institute for Materials Research
Job title
Specially Appointed Associate Professor(Research)
Degree

  • 博士（工学）（東京大学）

  • 修士（工学）（東京大学）

e-Rad No.
60997071

Papers 7

  1. A Molecular Adsorption Concept for Increasing Energy Density of Hybrid Supercapacitors International-journal Peer-reviewed

    Kosuke Ishibashi, Yutaro Hirai, Keisuke Oku, Koju Ito, Hiroshi Yabu

    ACS Applied Materials & Interfaces　2024/07/03

    DOI： 10.1021/acsami.4c06084 　

  2. Rare-metal-free hydrogen evolution reaction electrocatalysts based on metal azaphthalocyanine molecular layer for anion exchange membrane water electrolysis

    Yutaro Hirai, Kosuke Ishibashi, Keisuke Oku, Koju Ito, Hiroshi Yabu

    Discover Chemical Engineering　2024/06/19

    DOI： 10.1007/s43938-024-00050-z 　

  3. Porous honeycomb film membranes enhance endothelial barrier integrity in human vascular wall bilayer model compared to standard track‐etched membranes

    Neven A. Ebrahim, Olive N. Mwizerwa, Emmanuel C. Ekwueme, Tessa E. Muss, Erik E. Ersland, Takahiro Oba, Keisuke Oku, Masafumi Nishino, Daichi Hikimoto, Hayato Miyoshi, Kimihiko Tomotoshi, Craig M. Neville, Cathryn Sundback

    Journal of Biomedical Materials Research Part A　2023/05

    DOI： 10.1002/jbm.a.37517 　

    ISSN： 1549-3296 1552-4965

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    <jats:title>Abstract</jats:title><jats:p>In vitro vascular wall bilayer models for drug testing and disease modeling must emulate the physical and biological properties of healthy vascular tissue and its endothelial barrier function. Both endothelial cell (EC)‐vascular smooth muscle cell (SMC) interaction across the internal elastic lamina (IEL) and blood vessel stiffness impact endothelial barrier integrity. Polymeric porous track‐etched membranes (TEM) typically represent the IEL in laboratory vascular bilayer models. However, TEM stiffness exceeds that of diseased blood vessels, and the membrane pore architecture limits EC‐SMC interaction. The mechanical properties of compliant honeycomb film (HCF) membranes better simulate the Young's modulus of healthy blood vessels, and HCFs are thinner (4 vs. 10 μm) and more porous (57 vs. 6.5%) than TEMs. We compared endothelial barrier integrity in vascular wall bilayer models with human ECs and SMCs statically cultured on opposite sides of HCFs and TEMs (5 μm pores) for up to 12 days. Highly segregated localization of tight junction (ZO‐1) and adherens junction (VE‐cadherin) proteins and quiescent F‐actin cytoskeletons demonstrated superior and earlier maturation of interendothelial junctions. Quantifying barrier integrity based on transendothelial electrical resistance (TEER), membranes showed only minor but significant TEER differences despite enhanced junctional protein localization on HCF. Elongated ECs on HCF likely experienced greater paracellular diffusion than blocky ECs on TEM. Also, larger populations of plaques of connexin 43 subunit‐containing gap junctions suggested enhanced EC‐SMC communication across the more porous, thinner HCF. Compared with standard TEMs, engineered vascular wall bilayers cultured on HCFs better replicate physiologic endothelial barrier integrity.</jats:p>

  4. Human Vascular Wall Microfluidic Model for Preclinical Evaluation of Drug-Induced Vascular Injury

    Keisuke Oku, Erik Ersland, Neven Ebrahim, Olive Mwizerwa, Takahiro Oba, Masafumi Nishino, Daichi Hikimoto, Hayato Miyoshi, Kimihiko Tomotoshi, Omid Rahmanian, Emmanuel Ekwueme, Craig Neville, Cathryn Sundback

    Tissue Engineering Part C: Methods　2022/02/01

    DOI： 10.1089/ten.tec.2021.0227 　

    ISSN： 1937-3384 1937-3392

  5. Effect of Pore Size of Honeycomb‐Patterned Polymer Film on Spontaneous Formation of 2D Micronetworks by Coculture of Human Umbilical Vein Endothelial Cells and Mesenchymal Stem Cells

    Keisuke Oku, Kyohei Ohno, Daisuke Miyamoto, Koju Ito, Hiroshi Yabu, Kohji Nakazawa

    Macromolecular Bioscience　2021/10

    DOI： 10.1002/mabi.202100113 　

    ISSN： 1616-5187 1616-5195

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    <jats:title>Abstract</jats:title><jats:p>The geometrical control of micronetwork structures (NSs) formed by endothelial cells is an important topic in tissue engineering, cell‐based assays, and fundamental biological studies. In this study, NSs are formed using human umbilical vein endothelial cells (HUVECs) by the coculture of HUVECs and human mesenchymal stem cells (MSCs) confined in a honeycomb‐patterned poly‐<jats:sc>l</jats:sc>‐lactic acid film (honeycomb film (HCF)), which is a novel cell culture scaffold. The HCF is produced using the breath figure method, which uses condensed water droplets as pore templates. The confinement of the HUVECs and MSCs in the HCF along with the application of centrifugal force results in NS formation when the pore size is more than 20 m. Furthermore, NS development is geometrically restricted by the hexagonally packed and connected pores in the horizontal direction of the HCF. Network density is also controlled by changing the seeding density of the HUVECs and MSCs. The threshold pore size indicates that NSs can be formed spontaneously by using an HCF with a perfectly uniform porous structure. This result provides an important design guideline for the structure of porous cell culture scaffolds by applying a blood vessel model in vitro.</jats:p>

  6. Observation of Phase Transition from Dissolved Organic Semiconducting Materials to Solid Film during Drying

    Keisuke Oku, Susumu Inasawa, Yoshiko Tsuji, Yukio Yamaguchi

    Drying Technology　2012/06/15

    DOI： 10.1080/07373937.2012.668600 　

    ISSN： 0737-3937 1532-2300

  7. Quantitative Study of Surface Deprotonation Induced Settling Mode Transition of Silica Colloidal Particles

    Keisuke Oku, Susumu Inasawa, Yukio Yamaguchi

    JOURNAL OF CHEMICAL ENGINEERING OF JAPAN　2010

    DOI： 10.1252/jcej.10we131 　

    ISSN： 0021-9592 1881-1299

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