The nitric oxide treatment for cardiomyogenic commitment of Human Placental derived Stem Cells grown on Combined Synthetic-Fibrin Scaffold

Stem cell therapy is a very promising approach for the treatment of damaged myocardium. A suitable cell delivery system requires an appropriate stem cell source able to proliferate and differentiate, but also to be easily handled and have elastic properties without affecting the cardiac contractile function. Mesenchymal Stem Cells (MSCs) isolated from term Amniotic membrane (AM) are emerging as a very attractive source for cardiac repair, due to their multi-lineage differentiation potential and low immunogenic properties. In this study an elastic scaffold, obtained combining a fibrin layer with a poly(ether)urethane-polydimethylsiloxane (PEtU-PDMS) layer, was used as a substrate for in vitro studies of human amniotic mesenchymal stromal cell (hAMSCs) growth and differentiation. Cell proliferation and metabolic activity of hAMSCs seeded on the fibrin scaffold were evaluated by bromodeoxyuridine and WST-1 assays, for up to 14 days of culture. The beginning of cardiomyogenic commitment of hAMSCs grown on the scaffold was induced, for the first time in this cell population, by a nitric oxide (NO) treatment. The NO treated hAMSCs, showed morphological changes, an increase of the messenger cardiac differentiation markers [troponin I (TnI) and NK2 transcription factor related locus 5 (Nkx2.5)] and a modulation of the endothelial markers [vascular endothelial growth factor (VEGF) and kinase insert domain receptor (KDR)] by RT-PCR analysis. The results of this study propose a combined synthetic fibrin scaffold that allows a better proliferation and the beginning of the cardiomyogenic differentiation of hAMSCs suggesting a new strategy that could be used in cardiac regenerative medicine.