Strategic design of cardiac mimetic core-shell nanofibrous scaffold impregnated with Salvianolic acid B and Magnesium l-ascorbic acid 2 phosphate for myoblast differentiation.

The major loss of myocardial tissue extracellular matrix after infarction is a serious complication that leads to heart failure. Regeneration and integration of damaged cardiac tissue is challenging since the functional restoration of the injured myocardium is an incredible task. The injured micro environment of myocardium fails to regenerate spontaneously. The emergence of nano-biomaterials would be a promising approach to regenerate such a damaged cardiomyocytes tissue. Here, we have fabricated a dual bioactive embedded nanofibrous cardiac patch via coaxial electrospinning technique, to mimic the topographical and chemical cues of the natural cardiac tissue. The proportion and the concentration of the polymers were optimized for tailored delivery of bioactives from a spatio-temporally designed scaffold. The functionalization of polymeric core shell nanofibrous scaffold with dual bioactives enhanced the physico-chemical and bio-mechanical properties of the scaffolds that has resulted in a 3-dimensional topography mimicking the natural cardiac like extracellular matrix. The sustained delivery of bioactive signals, improved cell adhesion, proliferation, migration and differentiation could be attributed to its highly interconnected nanofibrous matrix with good extended morphology. Further, the expression of cardiac specific markers were found to increase on investigation of mRNA by real time PCR studies and proteins by immunofluorescence and western blotting techniques, confirming cell - biomaterial interactions. Flow cytometry analysis authenticated a potent mitochondrial membrane potential of cells treated with nanocomposite. In addition, in ovo studies in chicken chorioallantoic membrane assay confirm the efficacy of the developed scaffold in inducing angiogenesis required for maintaining its viability after transplantation onto the infarcted zone. These promising results demonstrate the potential of the composite nanofibrous scaffold as an effective biomaterial substrate for cardiac regeneration providing cues for development of novel cardiac therapeutics.