In vitro endothelial differentiation evaluation on polycaprolactone-methoxy polyethylene glycol electrospun membrane and fabrication of multilayered small-diameter hybrid vascular graft

During development of functional tissue engineered vascular graft, ensuring endothelialization at inner layer and mechanically strong outer layer is considered as challenging. The study objective was to fabricate a multilayered artificial blood vessel by dual syringe electrospinning technique. The presented graft was composed of polycaprolactone-methoxy polyethylene glycol which acts as an inner layer whereas Poly [4,4’-methylenebis(phenyl isocyanate)-alt-1,4-butanediol/di(propylene glycol)/polycaprolactone] (PUPCL) (12% w/v) was incorporated as the outer layer. To find out the optimum inner layer, different polycaprolactone-methoxy polyethylene glycol electrospun membranes varying methoxy polyethylene glycol content (0, 5, 10, 20, and 30% w/v) were prepared and evaluated. The characterizations revealed that blending of methoxy polyethylene glycol with polycaprolactone improved hydrophilicity and antithrombogenic properties compared to polycaprolactone or polyurethane polycaprolactone membrane. During in vitro assessment, the optimized polycaprolactone-20% methoxy polyethylene glycol membrane reinforced a greater differentiation of rat bone marrow stem cell into endothelial cells at both mRNA and protein levels by significantly inducing endothelial markers (CD31, Flk-1, and von Willebrand factor) expression. The polyurethane polycaprolactone membrane showed higher mechanical strength than polycaprolactone-methoxy polyethylene glycol while multilayered polycaprolactone-20% methoxy polyethylene glycol/polyurethane polycaprolactone vascular graft exhibited better result compared to single form. Therefore, the strong and bioactive polycaprolactone-20% methoxy polyethylene glycol/polyurethane polycaprolactone small diameter graft (<2 mm) prepared by simple fabrication process could be a promising preliminary platform for vascular tissue engineering application studies.