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 ~ 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.

Who Will Win: Induced Pluripotent Stem Cells Versus Embryonic Stem Cells for ß Cell Replacement and Diabetes Disease Modeling?

PURPOSE OF REVIEW: Ever since the reprogramming of human fibroblasts to induced pluripotent stem cells (hiPSCs), scientists have been trying to determine if hiPSCs can give rise to progeny akin to native terminally differentiated cells as human embryonic stem cells (hESCs) do. Many different somatic cell types have been successfully reprogrammed via a variety of methods. In this review, we will discuss recent studies comparing hiPSCs and hESCs and their ability to differentiate to desired cell types as well as explore diabetes disease models. RECENT FINDINGS: Both somatic cell origin and the reprogramming method are important to the epigenetic state of the hiPSCs; however, genetic background contributes the most to differences seen between hiPSCs and hESCs. Based on our review of the relevant literature, hiPSCs display differences compared to hESCs, including a higher propensity for specification toward particular cell types based on memory retained from the somatic cell of origin. Moreover, hiPSCs provide a unique opportunity for creating diabetes disease models.

Human pluripotent stem cell differentiation to functional pancreatic cells for diabetes therapies: Innovations, challenges and future directions.

Recent advances in the expansion and directed pancreatogenic differentiation of human pluripotent stem cells (hPSCs) have intensified efforts to generate functional pancreatic islet cells, especially insulin-secreting ß-cells, for cell therapies against diabetes. However, the consistent generation of glucose-responsive insulin-releasing cells remains challenging. In this article, we first present basic concepts of pancreatic organogenesis, which frequently serves as a basis for engineering differentiation regimens. Next, past and current efforts are critically discussed for the conversion of hPSCs along pancreatic cell lineages, including endocrine ß-cells and α-cells, as well as exocrine cells with emphasis placed on the later stages of commitment. Finally, major challenges and future directions are examined, such as the identification of factors for in vivo maturation, large-scale culture and post processing systems, cell loss during differentiation, culture economics, efficiency, and efficacy and exosomes and miRNAs in pancreatic differentiation.