Soft Hydrogels Support Differentiation of Induced Pluripotent Stem Cells toward Mesenchymal Stromal Cells [expression]

Induced pluripotent stem cells (iPSCs) can be differentiated toward mesenchymal stromal cells (MSCs), but at least on epigenetic level this transition remains incomplete with the current culture conditions. Hydrogels provide a more physiologic three-dimensional environment for in vitro cell culture than conventional tissue culture plastic (TCP). In this study, we followed the hypothesis that growth and differentiation of primary MSCs and of iPSC-derived MSCs (iMSCs) can be enhanced on hydrogels. To this end, we used a hydrogel made of human platelet lysate (hPL). MSCs were effectively cultured on and inside hPL-gel and demonstrated more structured deposition of extracellular matrix (ECM) components than TCP. Furthermore, hPL-gel supported differentiation of iPSCs toward MSCs. Unexpectedly, the differentiation process seemed to be hardly affected by the substrate: iMSCs generated either on TCP or hPL-gel did not reveal differences in morphology, immunophenotype, or differentiation potential. Moreover, global gene expression and DNA-methylation profiles were almost identical in iMSCs generated on TCP or hPL-gel. Our results indicate that matrix elasticity is less crucial for directed lineage-specific differentiation toward MSCs than expected.

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Goetzke R, Franzen J, Ostrowska A, Vogt M, Blaeser A, Klein G, Rath B, Fischer H, Zenke M, Wagner W