Covalent grafting of zwitterion polymer and REDV peptide onto NiTi alloy surface for anticoagulation and proendothelialization

Abstract Although stent implantation is an effective treatment for cardiovascular diseases, restenosis and thrombosis still remain great challenges clinically. To address these problems, modifying the stent surface with the bifunctions of anticoagulation and proendothelialization is considered as a promising strategy. Herein, zwitterion polymer poly (α‐methacrylic acid‐ co ‐2‐methylacryloxyethyl phosphorylcholine) (PMAMPC) and endothelial cells (ECs)‐selective adhesion peptide REDV were co‐modified onto the surface of NiTi stent by chemical graft to obtain NiTi‐PMAMPC/REDV stent. The introduction of PMAMPC and REDV peptide equip NiTi‐PMAMPC/REDV stent with satisfactory anticoagulation performance and enhanced endothelialization, respectively. The in vitro studies showed that NiTi‐PMAMPC/REDV surface had excellent blood compatibility, and could effectively promote the adhesion, proliferation and migration of human umbilical vein endothelial cells (HUVECs). Additionally, NiTi‐PMAMPC/REDV surface were capable of decreasing the adhesion of smooth muscle cells (SMCs). In vivo studies demonstrated that the NiTi‐PMAMPC/REDV stent could maintain good blood patency and form a relatively complete endothelial layer on the surface after 30 days in the rat aorta model. This bifunctional surface might hold great potential in relieving thrombosis and restenosis in the field of stent implantation.