Long-term expansion of human induced pluripotent stem cells in a microcarrier-based dynamic system

Abstract

BACKGROUND Human induced pluripotent stem (hiPS) cells provide a fascinating tool for exploring disease mechanisms, compound screening in pharmaceutical drug development, and might also represent a renewable source of cells for regenerative medicine applications. This requires increased cell quantities, generated under Good Manufacturing Practice-compatible conditions in a scalable system. RESULTS A microcarrier-based suspension culture was explored for scaling-up of hiPS cell expansion in serum-free medium using synthetic peptide-acrylate surface microcarriers, developed for long-term support of hiPS cell self-renewal. After a 7 days-culture in spinner flask, cells maintained their typical morphology, pluripotency-associated marker expression and their differentiation capability. Envisaging the improvement of the scalability of the culture, long-term expansion on the microcarriers was attained using confluent microcarriers as the inoculum of successive spinner flask cultures. Importantly, bead-to-bead cell transfer allowed 4 consecutive sub-culture procedures and a cumulative 241-fold expansion was achieved within 15 days, leading to a total viable cell number of 3.3x108 cells. CONCLUSION This work is expected to enable the scale-up of hiPS cell culture under defined conditions and potentially leading to the use of pluripotent stem cell derivatives in cell replacement therapies.