Systematically evaluate the physicochemical property and hemocompatibility of phase dependent TiO2 on medical pure titanium

In recent years, TiO2 nanotube has presented great potentials in blood-contacting implants. However, considering the reliability and safety of the application and complexity of coagulation mechanism, the physicochemical property and hemocompatibility of phase dependent TiO2 still need to be investigated deeply. In this research, the wettability, electrochemical properties, mechanical properties, and whole blood coagulation response of phase dependent TiO2 nanotubes were systematically evaluated. First, the surface topography and crystal phase of regular self-ordering TiO2 nanotubes arrays were characterized, some significant changes including fracture, collapse and micropores appeared with the increase of annealed temperature, which mainly caused by transformation of crystal structure. Secondly, the physicochemical properties were analyzed, which presented that the superhydrophilicity, hardness, elastic modulus, adhesive strength of TiO2 nanotubes gradually decrease with the increase of annealed temperature; the mean coefficient of friction increases when the crystal phase of TiO2 nanotubes transferred from amorphous into anatase, whereas it decreases with the increase of rutile phase content; and the rutile phase displays excellent resistant element precipitation due to the increase of grain boundary density and close packed crystal structure. Finally, the whole blood was applied to evaluate the hemocompatibility of phase dependent TiO(2 )nanotubes by in vitro experiment. The deteriorative surface morphology and lower interfacial tension of nanotubes array composed of rutile phase can effectively avoid adhesion and activation of platelets. This research can provide a useful guide to design theTiO(2) -nanotube-based blood compatible biomaterials.