Enhanced hydrophilicity and in vitro bioactivity of porous TiO2 film through the incorporation of boron

The aim of the current work is to prepare a novel boron-incorporated TiO2 film (B-TiO2 film) through MAO process in order to take advantages of the MAO technique and benefits of boron (B). The physicochemical properties and the in vitro bioactivity of B-TiO2 film are investigated in comparison with those of the control group without B (TiO2 film). Compared with TiO2 film, B-TiO2 film does not show obvious differences on morphology, surface roughness and phase composition. However, B-TiO2 film is found to be more hydrophilic than TiO2 film as the water contact angle decreases significantly from 77±1.7° to 65±3.1°. In simulated body fluid (SBF), an enhanced apatite-forming ability of B-TiO2 film is noticed compared to TiO2 film, indicating that the incorporation of B can improve the bioactivity of MAO-fabricated film. A possible mechanism is proposed to explain the enhanced bioactivity of B-TiO2 film. B is presented in MAO-fabricated film in forms of B2O3 and Ca2B2O5·H2O. Ca2B2O5·H2O is able to partially hydrolise in SBF and transform to boranol (B-OH) groups. The enhanced bioactivity might be attributed to the B-OH groups formed on the surface of B-TiO2 film in SBF. Results of the study suggest that B-TiO2 film is of great promise to be applied as bioactive material for biomedical applications.