Clump-passaging-based efficient 3D culture of human pluripotent stem cells under chemically defined conditions.

Large-scale production of human pluripotent stem cells (hPSCs) in an efficient and safe manner is crucial to the successful application of hPSCs in biomedical research and regenerative medicine. Three-dimensional culture methods for hPSCs have been extensively studied using single-cell passaging approaches; however, these techniques have been challenged by the induction of massive cell death and accumulation of genomic abnormalities. In this work, we developed and optimized a novel, simple clump-passaging method for in vitro hPSCs 3-dimensional (3D) culture that can be exploited for large-scale production. Fully grown hPSC spheroids were dissociated into smaller-sized spheroid clumps by simple treatment with enzyme-free dissociation buffer, and clumped hPSCs were inoculated and maintained for 3D suspension culture. Our clump-passaging method effectively increased the hPSCs survival rate after subculture and supported scalable hPSCs 3D expansion. We also tested and selected chemically defined media formulations that are suitable for 3D culture and commercially available. Overall, our clump-passaging and expansion method demonstrated high survival and expansion rates for hPSC spheroids compared with conventional methods and may also have the advantage of maintaining genomic stability.