https://bio.nikkeibp.co.jp/atcl/news/p1/24/11/22/12660/
https://elifesciences.org/articles/89724
A joint research group of RIKEN (RIKEN), Kyoto University iPS Cell Research Foundation, and Kaneka has developed a method for suspension culture of iPS cells while suppressing spontaneous differentiation. They have succeeded in consistently performing the process of establishing iPS cells from human peripheral blood mononuclear cells and mass culturing clinical-grade human iPS cells in suspension culture. The method involves simply adding two types of compounds that block differentiation-inducing signals, and existing commercially available culture media can be used.
The clinical iPS cell line was cultured in large quantities in a bioreactor under suspension culture conditions with the addition of signal inhibitors for Wnt and PKCβ. The cells were passaged three times at 3-4 day intervals into new medium, and about 300 frozen tubes containing about 1 million cells were produced per passage.
For clinical use of human iPS cells, it is necessary to efficiently establish human iPS cells in a closed system. Therefore, the research group attempted to establish human iPS cells under the suspension culture conditions they developed. Using human peripheral blood mononuclear cells as material, they produced human iPS cells by infection with Sendai virus vectors or gene transfer using episomal vectors. The gene-transduced cells were repeatedly passaged every 5 to 6 days and continued to be cultured in suspension. Furthermore, single cells were selected from the suspension cultured human iPS cells using FACS, and clones derived from these single cells were grown under suspension culture conditions to produce clone lines. The cell aggregates of this clone line showed a uniform spherical structure, and spontaneous cell differentiation was hardly observed. The clone line also maintained a normal karyotype, tested positive for self-renewal markers, and was found to have the pluripotency to differentiate into various types of cells.
Source of picture: https://www.kaneka.co.jp/assets/img/corporate/managementplan/en/5_R&D%20Topics.pdf
