Triblock Phospholipid Polymer/VEGF Bionic Multifunctional Coating Of Construction And Evaluation

Vascular stenting has been widely used in interventional therapy,has developed a metal bare stent,coated stent and drug-eluting stent,but the treatment of late restenosis and late thrombosis problem has been there.The traditional bare metal stents are used,since their excellent mechanical properties and processing properties.316L stainless steel is used for stent material with good biocompatibility.However,metal stents,long-term retention in the human body,will cause surface thrombosis and There are,in the fluid environment,metal ion dissolution.Furthermore,advanced thrombosis rate is also relatively high and other issues.In order to solve these problems of 316L stainless steel brackets,it is necessary to improve the biocompatibility of its surface.2-Methacryloyloxy Ethyl Phosphorylcholine(MPC)is an amphiphilic molecule,and the MPC polymer can form an imitation cell membrane.A large number of papers reported that MPC polymer immobilized on the surface of biological materials to improve the surface of the hydrophilic material,but also to the surface anti-platelet adhesion,anti-protein adhesion and cell adhesion performance.In the field of vascular stents,this anti-non-specific adhesion properties can inhibit the proliferation of endothelial cells on the surface of the material,which cannot be,in the early implantation,quickly endothelialization.Only relying on MPC polymer modified materials’surface cannot meet the clinical manifestations of vascular stents,which should give the surface of the material good biological functions,what is specifically promote endothelial cell adhesion and proliferation.In this paper,MPC monomer was polymerized with 3-(methacryloyloxy)propyltrimethoxysilane(3-(Methacryloyloxy)Propyltrimethoxysilane,TMSPMA)by atom transfer radical polymerization(ATRP)to synthesize the triblock copolymer of MePBMTMⅠ,Ⅱ,Ⅲ with different molecular weights;three kinds ’random phospholipid copolymers of PMTs,which have different molecular weight could be prepared by the method of traditional free radical polymerization.Phospholipids copolymer coatings were prepared by immobilizing triblock phospholipid copolymers and random phospholipid copolymer to 316L stainless steel surface.The results of anticoagulation and cell evaluation demonstrated that the triblock phospholipid copolymer coating was superior to the random phospholipid polymer coating in preventing platelet adhesion and denaturation,fibrinogen adhesion and denaturation,and cell adhesion and proliferation.MePBMTM Ⅲ coating has the best coating performance as a platform for further modification.Vascular Endothelial Growth Factor(VEGF),which is specific for endothelial progenitor cells,was immobilized on MePBMTM Ⅲ coating.The culture of smooth muscle cells and endothelial progenitor cells proved that the triblock phospholipid polymer/VEGF coating significantly promoted the proliferation of surface endothelial progenitor cells and inhibited the proliferation of smooth muscle cells.