Biotechnology and Bioengineering, Vol.118, No.2, 979-991, 2021
Non-xenogeneic expansion and definitive endoderm differentiation of human pluripotent stem cells in an automated bioreactor
Scalable processes are requisite for the robust biomanufacturing of human pluripotent stem cell (hPSC)-derived therapeutics. Toward this end, we demonstrate the xeno-free expansion and directed differentiation of human embryonic and induced pluripotent stem cells to definitive endoderm (DE) in a controlled stirred suspension bioreactor (SSB). Based on previous work on converting hPSCs to insulin-producing progeny, differentiation of two hPSC lines was optimized in planar cultures yielding up to 87% FOXA2(+)/SOX17(+) cells. Next, hPSCs were propagated in an SSB with controlled pH and dissolved oxygen. Cultures displayed a 10- to 12-fold increase in cell number over 5-6 days with the maintenance of pluripotency (>85% OCT4(+)) and viability (>85%). For differentiation, SSB cultures yielded up to 89% FOXA2(+)/SOX17(+) cells or similar to 8 DE cells per seeded hPSC. Specification to DE cell fate was consistently more efficient in the bioreactor compared to planar cultures. Hence, a tunable strategy is established that is suitable for the xeno-free manufacturing of DE cells from different hPSC lines in scalable SSBs. This study advances bioprocess development for producing a wide gamut of human DE cell-derived therapeutics.
Keywords:definitive endoderm (DE) differentiation;human pluripotent stem cells (hPSCs);pluripotent expansion;stirred suspension bioreactor (SSB);xeno-free