Anodic TiO₂ Nanotubular Arrays with Pre-Synthesized Hydroxyapatite—An Effective Approach to Enhance the Biocompatibility of Titanium

Electrochemically anodized TiO₂ nanotubular arrays can provide large surface areas for biological species attachment. In order to further enhance the biocompatibility of Ti medical implants, we deposited a pre-synthesized hydroxyapatite inside and on the nanotubular arrays, and examined the biocompatibility of the anodized TiO₂ nanotubular arrays with pre-synthesized hydroxyapatite by in vitro assessment in simulated body fluid, and in vitro cell culture. The results showed that the hydroxyapatite coating was able to be induced on TiO₂ nanotubular arrays with pre-synthesized hydroxyapatite within 5 days while only a thin film composed of calcium phosphorous chemicals formed on as-formed TiO₂ nanotubular arrays. The cell culture evaluation further proved the enhancement of cell attachment and proliferation on TiO₂ nanotubular arrays with pre-synthesized hydroxyapatite as opposed to those without pre-synthesized hydroxyapatite. The present study proves that formation of TiO₂ nanotubular arrays with pre-synthesized hydroxyapatite a promising method to enhance the biocompatibility of Ti implants.