Study On Catalytic Release Of NO And Biocompatibility Of Ti-Cu Films

The cardiovascular materials should have better inhibitor of smooth muscle cell(SMC),promote endothelial cell(EC)proliferation and achieve the effect of vascular repair,while meet good anticoagulant.Nitric oxide(NO)as the endothelium derived relaxing factor(EDRF)modulates the cardiovascular system stability,which can promote endothelialization,inhibit SMC proliferation and platelet adhesion and activation.Based on this,we want to build a layer with catalytic release of NO in this paper.It is reported that the trace element Cu can catalyze NO release from NO-donor(SNAP)with existence of reductor,the Cu shuld be the best choice for cardiovascular stents with anticoagulant.Therefore,we want to gain different amounts of Cu doped Ti films surface with catalytic release of NO to improve the biocompatibility of stents surface.Cu-doped(11.39,40.29,43.11 and 36.39 at.%)Ti coatings were fabricated on 316L SS and silicon wafers(100)via direct current magnetron sputtering(DCMS)in this study.The structure of Ti-Cu films are Ti phase(TilOCu,200 nm),amorphization(Ti40Cu-1,200 nm and Ti40Cu-3,1500 nm)and Cu phase(Ti40Cu-2,1500 nm)respectively.And do a series of materials characterization(including XRD,EDS,WCA,SEM,AFM,electrochemical corrosion,copper ions release and catalytic release of NO)and biological characterization(including EC,SMC and platelet experiment).Electrochemical corrosion results implied Ti-Cu films had good corrosion resistance behavior compared to 316L SS,and it would be decrease while the structres changed from Ti to Cu.Copper ions release and catalytic release of NO result showed that Ti-Cu films could realizelong-term release of copper ions effectively,to achieve long-term catalytic release of NO.And the catalytic behaviour was stronger while the structres changed from Ti to Cu.Moreover,the cells experiment(EC,SMC)showed that Ti-Cu films with good cytocompatibility could release copper ion from films to promote endothelialization.And the EC could be better proliferation and inhibit hyperplasia of SMC after cultured with NO-donor on Ti-Cu surfaces(Ti10Cu and Ti40Cu-1).The platelet result suggested that Ti-Cu films could inhibit the platelet adhesion and activation after cultured with NO-donor.In conclusion,we successfully build Ti-Cu thin films with catalytic release of NO using an unbalanced magnetron sputtering(UBMS450),regulating the copper ion release to realize long-term catalytic release of NO and promote endothelialization,inhibit the hyperplasia of smooth muscle cells and platelet adhesion and activation,and prevent thrombosis.Ti-Cu films with good biological compatibility have potential applacation in cardiovascular stents.