Titanium Dioxide Nanotubes Incorporated Bioactive Glass Nanocomposites: Synthesis, Characterization, Bioactivity Evaluation and Drug Loading

Nano bioactive glasses are known as suitable alternatives to repair the damaged bone tissues. In this research, novel sol-gel derived bioactive glass composites were synthesized through a reduction in the common weight percent of SiO2 substituted by 15 wt% of titanium dioxide nanotubes (TNTs) at two different steps by the synthetic procedure. The morphology, crystalline structure, and functional groups of the composites were evaluated through scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) analyses. Based on the SEM images, the step in which TNTs were added to the solution completely changed the morphology of the composite. Bioactivity tests were carried out by soaking the samples in the simulated body fluid (SBF) at the intervals ­of 14 and 28 days followed by the investigation of hydroxyapatite (HA) layer formation on the surface of the samples. According to XRD peaks at 2-theta angle of around 31 and 40 degrees, it was found that the presence of titanium dioxide nanotubes improved bioactivity after 14 days of immersion and both 58S-TNT composites were more bioactive than 58S bioglass, while 58S bioactive glass possessed more intense peaks of HA after 28 days of immersion in SBF. Furthermore, the drug loading characteristic of the prepared composites was examined and the results showed that the addition of nanotubes improved the drug loading performance of bioactive composites containing TNTs up to 70% compared to the 58S bioglass with 37% drug loading.