Fabrication of graphene-silver/polyurethane nanofibrous scaffolds for cardiac tissue engineering

The graphene-based nanocomposites are considered as great candidates for enhancing electrical and mechanical properties of nonconductive scaffolds in cardiac tissue engineering. In this study, reduced graphene oxide-silver (rGO-Ag) nanocomposites (1 and 2 wt%) were synthesized and incorporated into polyurethane (PU) nanofibers via electrospinning technique. Next, the human cardiac progenitor cells (hCPCs) were seed on these scaffolds for in vitro studies. The rGO-Ag nanocomposites were studied by X-ray diffraction (XRD), Raman spectroscopy, and transmission electron microscope (TEM). After incorporation of rGO-Ag into PU nanofibers, the related characterizations were carried out including scanning electron microscope (SEM), TEM, water contact angle, and mechanical properties. Furthermore, PU and PU/nanocomposites scaffolds were used for in vitro studies, wherein hCPCs showed good cytocompatibility via 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and considerable attachment on the scaffold using SEM studies. Real-time polymerase chain reaction (PCR) and immunostaining studies confirmed the upregulation of cardiac specific genes including GATA-4, T-box 18 (TBX 18), cardiac troponin T (cTnT), and alpha-myosin heavy chain (alpha-MHC) in the PU/rGO-Ag scaffolds in comparison with neat PU ones. Therefore, these nanofibrous rGO-Ag-reinforced PU scaffolds can be considered as suitable candidates in cardiac tissue engineering.