Preparation and Assessment of Nitric Oxide-Releasing Small-Diameter Collagen-Based Vascular Graft for Vascular Regeneration Applications

Endothelialization and antithrombosis are the keys for small-diameter vascular grafts to reduce thromboembolism and intimal hyperplasia and achieve revascularization. Nitric oxide (NO) is an essential antiplatelet, proendothelialization, and vasodilating agent. Meanwhile, owing to its good biocompatibility, collagen is long considered a feasible material for manufacturing small-diameter vascular grafts. However, thrombosis and poor mechanical strength remain major drawbacks. A collagen methacrylamide-co-selenocysteine (Col-MA-Se) composite capable of catalyzing NO release is synthesized here. The Col-MA-Se composite improves the blood compatibility of collagen and stimulates the migration and growth of endothelial cells, which suggests that the Col-MA-Se composite is suitable for small-diameter vascular grafts. The prepared composite is then incorporated with polycaprolactone (PCL) to prepare small-diameter vascular grafts that satisfying basic mechanical requirements for transplantation, followed by a comprehensive exploration of its mechanical strength, endothelial cell response, and platelet behavior. Results confirm the successful construction of collagen/PCL vascular grafts capable of releasing NO and affording rapid endothelialization and antithrombosis, which indicate their promising application prospects for vascular regeneration.