Institute of Industrial Science
Researchers at the Institute of Industrial Science, the University of Tokyo have demonstrated highly efficient expansion of human iPS cells in core-shell microfibers. This culture system is expected to be applied to large-scale expansion of human pluripotent stem cells for use in regenerative medicine.
The research group led by Professor Shoji Takeuchi and graduate student Kazuhiro Ikeda at the Institute of Industrial Science, the University of Tokyo, successfully developed a 3D culture system which allowed highly efficient expansion of human induced pluripotent stem cells (iPS cells) within core-shell microfibers by using "cell-fiber technology".
In fundamental research, human iPS cells are conventionally maintained in a surface-attached 2D culture system in culture dishes and flasks. 2D culture system is suitable for lab-scale cell culture because of the good operability and reproducibility. On the other hand, to obtain large numbers of human iPS cells and iPS cell-derived cells required for regenerative medicine, 3D culture system is an attractive strategy for the scalability and cost-efficiency. However, heterogeneous size of cell aggregations tend to be observed in conventional 3D culture system of human iPS cells (e. g. suspension culture system); leading to cell death likely caused by limited diffusion of gases and nutrients into the aggregations, decreasing in the expansion rate and loss of pluripotency of the cell.
The research group fabricated human iPS cell-laden core-shell microfibers (human iPS cell-fibers) by using cell-fiber technology. In cultured human iPS cell-fiber, the encapsulated cells expanded and formed the thin fiber-shaped aggregations in the core region of the microfiber. The thickness restriction of the aggregations resulted in suppression of cell death. Additionally, the cell encapsulation and culture with extra cellular matrix enhanced expansion rate of human iPS cells. Furthermore, the efficient expansion rate and the cell properties were sustained in human iPS cell-fibers for more than 1 month through serial passaging in this culture system. The theoretical accumulative expansion rate of human iPS cells was reached to ca. 109 -fold in about a month. This is the highest reported level of human iPS cell expansion in a culture system.
This culture system using human iPS cell-fiber is an important achievement toward realization and popularization of regenerative medicine as a fundamental technology for the cell expansion.
Ideally, this section should give the reader an idea of the researcher's personality, through their motivations for this research or their reaction to the outcome.
"Fiber" is a material that has been used for a long time. We here focus on the fiber's property of "constant in thickness and scalable in length" when in cell culture. We hope that this technology also brings the new biomedical field to the conventional fiber industry.
Kazuhiro Ikeda, Shogo Nagata, Teru Okitsu, and Shoji Takeuchi, "Cell fiber-based three-dimensional culture system for highly efficient expansion of human induced pluripotent stem cells", Scientific Reports,doi: 10.1038/s41598-017-03246-2
Article link https://www.nature.com/articles/s41598-017-03246-2
Article link https://www.iis.u-tokyo.ac.jp/ja/news/2713/
Shoji Takeuchi, Professor