Nobuhiko Kojima, Ph.D.
Professor, Laboratory of Regenerative Biology,
Department of Life and Environmental System Science,
Graduate School of Nanobioscience, Yokohama City University, Japan
Does Engineering an Organ Mean Reproducing the Real Organ?
Abstract
I have pursued the engineering of organs for nearly three decades. In tissue engineering, considerable effort has been devoted to reproducing the structures and functions of biological organs. This raises a fundamental question: does engineering an organ necessarily require faithfully reproducing its natural counterpart? Depending on the purpose, it may be more appropriate to redesign tissue architecture and composition according to the functions to be achieved.
My research has focused on three-dimensional tissue engineering based on cell aggregates, initially with the aim of reproducing tissue architecture and the microenvironment as faithfully as possible (Reproduce). I have developed heterogeneous spheroids composed of hepatocytes and vascular endothelial cells, hepatocyte spheroids incorporating hydrogel beads to enhance mass transport, and spheroids incorporating extracellular matrix (ECM) to reproduce cell–ECM interactions and cellular polarity.
As my research progressed, I began to modify these components according to specific purposes. Hydrogel beads were incorporated to create tissue architectures suitable for xenogeneic islet transplantation, while changes in ECM composition were used to develop islet disease models. I have also explored hydrogel-bead incorporation to improve spheroid transparency for image-based analysis. These studies represent different forms of tissue redesign, in which tissue architecture and composition are intentionally modified to achieve specific functions or purposes (Redesign).
This perspective has also led to the development of a “liquid liver,” in which liver-associated functions are reconstructed using cells, biomaterials, and functional components without reproducing the anatomical structure of the liver itself. Rather than asking “How should we build a liver?”, the focus shifts to “How can we achieve the functions that are needed?”
In this talk, I will introduce the ideas and fabrication approaches that have shaped my work on spheroid design, together with examples of tissue redesign. I hope this perspective will provide young researchers in cell-based engineering with both practical insights and a different way of thinking about how to design their research.
Curriculum Vitae
Dr. Nobuhiko Kojima is a Professor at Yokohama City University. His research focuses on three-dimensional cell culture, tissue engineering, regenerative medicine, and microphysiological systems (MPS), with particular emphasis on the design and control of cellular microenvironments.
Education
1996 Bachelor of Engineering, Osaka University
1998 Master of Engineering, Osaka University
2001 Ph.D. in Biochemistry, The University of Tokyo
Professional Experience
2001–2003 Research Scientist, Kanagawa Academy of Science and Technology
2003–2006 Research Associate, The University of Tokyo
2007–2009 Senior Researcher, UCLA and VAGLA Healthcare System
2009–2013 Project Assistant Professor, The University of Tokyo
2013–2024 Associate Professor, Yokohama City University
2022–2025 Chief Technology Officer (CTO), Ecocell Inc.
2024–present Professor, Yokohama City University
2024–present Director, Career Support Center, Yokohama City University
2024–present Assistant to the President, Yokohama City University
Research Interests
Three-dimensional cell culture and tissue engineering
Spheroids and organoids
Microphysiological systems (MPS)
Regenerative medicine
Physical microenvironment and cellular engineering