Superior Red Blood Cell Generation from Human Pluripotent Stem Cells Through a Novel Microcarrier-Based Embryoid Body Platform

Conventional methods for hematopoietic differentiation of human pluripotent stem cells (hPSC) rely on embryoid body (EB) formation and/or co-culture with xenogeneic cell lines. In this study, the authors describe the development of a scalable, serum-free, xeno-free, and chemically defined microcarrier-based platform using human recombinant laminin-521 as an extracellular matrix (ECM) for hPSC expansion, EB formation, and subsequently hematopoietic differentiation of hPSC to red blood cells (RBS). Improved survival and better quality EBs generated with the microcarrier-based method resulted in significantly improved mesoderm induction and, when combined with hematopoietic differentiation, resulted in at least a 6-fold improvement in hematopoietic precursor expansion, potentially culminating in an 80-fold improvement in the yield of RBS generation compared to a conventional EB-based differentiation method. In addition, they show efficient terminal maturation and generation of mature enucleated RBCs using a co-culture system that comprised primary human mesenchymal stromal cells.