The Preparation And Study Of Ti-O And Ti-(Cu)-O Thin Film

The principal problem associated with blood-contacting biomedical device and artificial organs is insufficient blood compatibility. A desire to solve this problem has prompted researchers to develop new materials and improved approaches. Surface modification has been shown to be one significant method to improve anticoagulation of conventional biomaterial contacted with blood.Titanium oxide films are deemed to be the promising materials for cardiovascular devices due to good mechanical properties, stable chemical properties and good biocompatibility of films. The deposition of titanium oxide films on the surface of the cardiovascular materials such as stents, can effectively improve the blood compatibility. As is well known, titanium oxide films have many different structures, such as rutile, anatase, broointe, and amorphous structure. And both the sputtering power supply and the substrate have a significant effect on the structure and surface properties of films. This will affect the blood compatibility properties as consequence. In this paper, titanium oxide films were fabricated on Silicon and Stainless steel substrates by both high-power pulsed magnetron sputtering (HPPMS) and direct current magnetron sputtering (DCMS). The plasma composition and the microstructure, adhesion strength, platelet adhesion behavior of titanium oxide films were investigated. The results indicated that the target ionization degree and the plasma density of HPPMS were higher compared with DCMS at the same target average power. Pure rutile phase was fabricated on Stainless steel substrates by both HPPMS and DCMS. Titanium oxide films with rutile structure can effectively inhibit platelet adhesion and activation. However, the content of rutile phase deposited by HPPMS was higher compared to that by DCMS. Furthermore, a denser structure, smooth surface and good adhesion strength of titanium oxide films can be fabricated by HPPMS technology. And titanium oxide films deposited by HPPMS showed a better blood compatibility compared to that by DCMS.Copper ions can effectively promote the NO release of vascular endothelial cell, thereby inhibiting platelet activation and aggregation to improve the anticoagulation hemorrhagic. In this paper, Ti-(Cu)-O films were fabricated on Silicon and Stainless steel substrates on the basis of good inhibiting platelet adhesion of titanium oxide films. The influence of copper content on the structure, adhesion strength, corrosion resistance of films was investigated. The behavior of copper release, the ability of catalytic NO releasing from S-nitroso-N-acetyl-pencillamine (SNAP) and blood compatibility were also studied. The results indicated that the Cu concentration of Ti-(Cu)-O films fabricated by copper-embedded titanium target (TiCu70 and TiCu210) were 30.4 wt% and 50.4 wt%, respectively. XRD and TEM results showed that Ti-(Cu)-O films were amorphous structure and CU2O phase appeared in the micro area. XPS result showed that CuO phase appeared in the films with higher Cu concentration (50.4 wt%). Compared with titanium oxide films, Ti-(Cu)-O films had higher hydrophobic, better film/substrate adhesion and decreased corrosion resistance. Inductively coupled plasma emission spectrum (ICP-MS) result showed that Ti-(Cu)-O films in the soaking liquid could release Cu ions. And the quantity of Cu ions increased with increasing immersion duration. At the same immersion duration, the quantity of Copper ions releasing of Ti-(Cu)-O films with higher Cu concentration (50.4 wt%) was higher than that of Ti-(Cu)-O films with lower Cu concentration (30.4 wt%).Ti-(Cu)-O films could catalyze to generate NO from SNAP species and the Ti-(Cu)-O films with higher Cu concentration had a higher NO releasing rate. The activation and adhesion of platelet were inhibited by Ti-(Cu)-O films in the presence of SNAP. The Ti-(Cu)-O film with higher copper concentration has a better ability of the inhibition of platelet adhesion.