Study Of Bioactive Coatings On The Surface Of Titanium And Nitinol

Titanium and Nitinol (NiTi) have been widely used as bone connector and artificial joints because of their good biocompatibility; NiTi also applies to vascular stent materials. The material has good biological activity and fast growth function for bone plant material.In order to avoid the thrombosis after implantation,the stent materials could promote endothelial growth. However their still have some drawbacks in practice that limited the further use of titanium. Because of bio-inertia, titanium implant can't form bone bonding with surrounding tissue, and NiTi have issues of Ni2+ ion toxicity, thrombosis, and so on.In order to improve the biocompatibility of titanium and nickel titanium alloy,the bioactive coating should be prepared.In order to improve the biological activity of NiTi alloy and inhibit the spill of Ni ions, a dense and porous coating on NiTi alloy was fabricated by applying a hybrid treatment of micro-arc oxidation (MAO) and arc ion plating. Structure and Properties of coatings were characterized using SEM, EPMA, XRD for different voltage,different duty cycle and different oxide time. The size of the pores and the content of TiO2 increases with the electric parameters increasing, the Ni content of coating remained less than 2%. The blood compatibility of coatings was characterized by platelet adhesion test and dynamic clotting test. The results show that the coating has less platelets adhesion and the clotting time is longer. The antithrombotic was improved by hybrid treatment.In order to improve the rapid endothelial function of NiTi alloy,a composite coating Ti/TiO2/CD34+ were prepared on the surface of porous NiTi via electrostatic self-assembly. The erosion-resistant performance of the coating was studied in Kokubo PBS. The results show that the antibody coating have good adhesion. The platelet adhesion experiment shows that the antibody coating has good antithrombotic properties. The dynamic blood clotting test shows that the clotting time of coating was longer than NiTi substrate. The antibody coating have good blood compatibility.In order to improve the growth ability of titanium alloy bone implant,a porous composite coating TiO2/HAp were prepared on the surface of titanium alloy by micro-arc oxidation and electrochemical deposition.Experiment mainly investigated the surface morphology of the HAp coating in different pH value and different voltage.The HAp coating was the most dense and highly crystallinity when sedimentary voltage was 3v,PH value was 5.