Modification And Bioactivc Of TiO₂Nanotube Arrays

Titanium and titanium alloys are widely used in biomedical devices, especially as hardtissue replacements as well as in cardiac and cardiovascular applications, because of theirdesirable properties. However, they cannot meet all of the clinical requirements. Titaniananotubes （NTs） fabricated by electrochemical anodization have been demonstrated to promotebone cell functionalities in vitro and bone implant osseointegration in vivo because of theirnanostructured surface. But, the osteogenic differentiation and antibacterial property of NTsalso cannot meet the requirements when they being used as dental and orthopedic implants.Therefore, in order to improve the biological properties, surface modification is oftenperformed. By chemical methods, the trace elements which can promote the integration of bonecan be doped into the TiO₂nanotube to form a composite structure which has the function ofslow-release, that provides a good direction for the development of Ti implant materials, too.Moreover, the typical open volume in TiO₂nanotubes can be exploited as an excellent drugloading and delivering platform. The main results are summarized as follows:（1） The coatings containing NTs incorporated with zinc （NT-Zn） are produced on Tiimplants by anodization and hydrothermal treatment in Zn containing solutions. The amount ofincorporated Zn can be adjusted by varying the structural parameters such as the nanotubediameter and length as well as hydrothermal treatment time. The suitable NT-Zn coatings withgood antibacterial properties can prevent post-operation infection. Excellent osteogenesisinducing ability in the absence of extraneous osteogenic supplements is demonstrated. TheNT-Zn structure which is simple, stable, and easy to produce and scale up has immensepotential in bone implant applications.（2） Titania coatings are synthesized on Ti implants by anodization, and then we can obtaina silanized surface after the hydroxyl groups on the TiO₂surface react with the Si end ofAPTES. Then using the anhydrous functionalization procedure, the drug of sodium alendronate（NaAL） was loaded into the TiO₂nanotubes by the amino functional groups. We sdudied themechanism of the functionalization procedure and the adsorption, release, detection of NaALdetailedly. And this sample also has immense potential in bone implant applications.