Human iPSC-derived mesenchymal stem cells matured into valve interstitial-like cells using PEGDA hydrogels

Despite recent advances in tissue engineered heart valves (TEHV), a major challenge is identifying a cell source for seeding TEHV scaffolds. Native heart valves are durable because valve interstitial cells (VICs) maintain tissue homeostasis by synthesizing and remodeling the extracellular matrix. In this study, the goal is to demonstrate that induced pluripotent stem cells (iPSC)-derived mesenchymal stem cells (iMSCs) can be derived from iPSCs using a feeder-free protocol and then further matured into VICs by encapsulation within 3D hydrogels. The differentiation efficiency was characterized using flow cytometry, immunohistochemistry staining, and trilineage differentiation. Using our feeder-free differentiation protocol, iMSCs were differentiated from iPSCs and had CD90 + , CD44 + , CD71 + , αSMA + , and CD45 − expression. iMSCs underwent trilineage differentiation when cultured in induction media for 21 days. iMSCs were encapsulated in poly(ethylene glycol) diacrylate (PEGDA) hydrogels, grafted with adhesion peptide (RGDS), to promote remodeling and further maturation into VIC-like cells. VIC phenotype was assessed by the expression of alpha-smooth muscle actin (αSMA), vimentin, and the collagen production after 28 days. When MSC-derived cells were encapsulated in PEGDA hydrogels that mimic the leaflet modulus, we observed a decrease in αSMA expression and increase in vimentin. In addition, iMSCs synthesized collagen type I after 28 days in 3D hydrogel culture. Thus, the results from this study suggest that iMSCs may be a promising cell source for TEHV.