Functional comparison of beating cardiomyocytes differentiated from umbilical cord-derived mesenchymal/stromal stem cells and human foreskin-derived induced pluripotent stem cells.

In recent years, stem cell-based therapies shown to have promising effects on the clinical management of ischemic heart disease. Moreover, stem cells differentiation into cardiomyocytes (CMs) can overcome the cell source limitations. The current research involves the isolation and expansion of mesenchymal stem cells (MSCs) and induced pluripotent stem cells (iPSCs), their differentiation into CMs and subsequent construction of tissue-engineered myocardium supported by random and aligned polycaprolactone (PCL) nanofibrous matrices (av. dia: 350-850 nm). Umbilical cord matrix (UCM)-derived MSCs were isolated successfully by routine enzymatic digestion and a nonenzymatic explant culture method and characterized by their morphology, differentiation into different lineages, and surface marker expression. Treatment of UCM-derived MSCs with 5-azacytidine (5 μM) induced their differentiation into putative cardiac cells, as revealed by the expression of cardiac-specific troponin T (cTnT), smooth muscles actin, myogenin (MYOG), smoothelin, cardiac α-actin genes and cTnT, α-actinin proteins by RT-PCR and immunocytochemistry, respectively. However, no beating cells were observed in differentiated MSCs. On the other hand, adult human foreskin-derived iPSCs cultured on Matrigel™-coated aligned PCL nanofibrous matrices showed anisotropic behavior along the PCL nanofibers and, upon differentiation, expressed cardiac-specific cTnT (23.34 vs. 32.55%) proteins and showed more synchronized beating than those differentiated on Matrigel™-coated tissue culture coated polystyrene surfaces. Moreover, aligned PCL nanofibers are able to promote cells orientation parallel to the fibers, thus providing an effective way to control anisotropic nature under in vitro condition.