Cytocompatibility and antibacterial property of N+ ions implanted TiO2 nanotubes

The N+ ions doped TiO2 nanotubes (TNTs) were prepared by the methods of ion implantation and anodization. Phase and chemical composition, surface morphology and water contact angle of the samples were examined. The corrosion behavior of the samples in simulated body fluids was estimated by electrochemical impedance spectroscopy and polarization resistance measurements. L-929 fibroblast cells were used to identify the cytotoxic response of N+ ions implanted TNTs. The density of the viable cells was determined by MTT assay. The antibacterial activities of N+ ions implanted TNTs were studied by sterilization of E. coli in the dark. Compared to TNTs, N+ ions implanted TNTs exhibited more regular surface, and the corrosion resistance of N+ ions implanted TNTs was improved. The N+ ions implanted TNTs possessed better hydrophilicity. The water contact angle of implanted samples was decreased with the increase of implanted dose. In vitro cell culture experiments, it identified that the N+ ions implanted TNTs were more favorable for cell attachment and proliferation. All the implanted samples showed antibacterial activity in the dark. The amounts of E. coli on the implanted sample with 5 × 1017 ions/cm2 reduced by about 63.1% after 24 h compared to control sample.