Development of small caliber tissue engineering bypass graft using polyurethane based nanofibrous scaffold

IntroductionMost prosthetic vascular grafts produced from biocompatible polymers have low patency rate for replacement of small diameter vessels (<5 mm), essentially due to thrombosis and graft/vessel hemodynamic mismatch, leading to intimal hyperplasia.ObjectivesOne of the best strategies to overcome these complications is rapid in-situ endothelialization of vascular grafts.MethodsFor this purpose, electrospun fibers of polyurethane (PUNF) were surface modified with a layer of PDA using in situ aqueous polymerization, and then PDA-coated fibers were immobilized with Heparin and VEGF. Scanning electron microscopy (SEM), water contact angle (WCA) quantities, and Raman spectroscopy was used to characterize of membrane surface, and tensile test was used for analyzing of mechanical properties before and after surface modification.ResultsAfter PDA coating on PUNF membrane (D-PUNF), Tensile strength were significantly increased. Immobilization of VEGF on the scaffold highly enhanced proliferation of human umbilical vein endothelial cells (HUVECs) that PDA layer before had enhanced cells adhesion and resulted in excellent cell-scaffold and cell to cell interaction. The water CA of the scaffold with dual-factor (VH-D-PUNF) was 54.03±0.89º. Endothelial cells display poor adhesion and proliferation behavior on hydrophobic materials, whereas endothelial cells behavior is enhanced on moderately water-wettable polymers.ConclusionPolymer with water CA 55◦ resulted in maximal cellular adhesion, enhanced proliferation rates, and cellular growth regardless of cell type. So VH-D-PUNF scaffold resulted in not only confluent monolayer of endothelial cells but also conferred excellent antithrombotic properties to the surface

کلیدواژه ها:

Vascular grafts ، Endothelialisation ، Polyurethane ، Nanofiber ، Surface modification