Characterization of self-organized TiO2 nanotubes on Ti–4Zr–22Nb–2Sn alloys and the application in drug delivery system

In this study, the self-organized TiO2 nanotubes grown by anodization of Ti–4Zr–22Nb–2Sn at different potentials, concentration of NH4F and anodization time was investigated. The morphology of nanotubes was observed by FE-SEM. The drug-loaded nanotubes were also fabricated in aqueous media containing minocycline hydrochloride. They were characterized by SEM, XPS and FT-IR. The results showed that the drug of minocycline hydrochloride (MH) was loaded in the nanotubes. The release effects were studied in phosphate buffer solution (PBS). The release rate of MH from TiO2 nanotubes with shorter tube length in PBS was lower than the one of MH from longer nanotubes. The sustaining release time could last at least 150 h. Hence, it is a promising method to eliminate the harmful reactions by carrying drug in the tubes when the titanium alloys were used as biomedical implants.