Improved Biocompatibility of TiO₂ Nanotubes via Co-Precipitation Loading with Hydroxyapatite and Gentamicin

The antibacterial properties of titanium make it useful for clinical applications. Hydroxyapatite (HA) is widely utilized as a coating on orthopedic implants to improve osteointegration. Titanium oxide nanotubes (TNT) are recognized as a promising solution for local antibiotic therapy in bone implants. It is demonstrated that the utilization of HA-coated titanium can improve the biocompatibility of bone implants. This research aims to examine the antibacterial properties and biocompatibility of the TiO2 nanotubes by loading HA and gentamicin. In vitro testing, the characterization of drug release, cell adhesion and proliferation, bacteria culture, and antibacterial tests were conducted. During the in vivo experiments, Staphylococcus aureus was implanted into the femur of rats. The animals were sacrificed at four weeks followed by microbiological and clinical assessments on the bone, which were conducted by removing the implants followed by agar plating. The in vitro cell incubation demonstrated that the TiO2 nanotubes loaded with hydroxyapatite and gentamicin had better cellular compatibility compared to Cp–Ti. In addition, in vitro elution testing showed that gentamicin was released from the hydroxyapatite/TiO2 nanotubes for as long as 22 days. The release time was much longer than the TNT loaded with gentamicin at only 6 h. All animals in the gentamicin/HA/TNT group were free of infection compared to those in the Cp–Ti, TNT, and HA/gentamicin/TNT groups. There was a considerable reduction in the rates of infection among the rats with gentamicin-HA-TNT coatings compared to standard titanium. These results indicated that the co-precipitation of gentamicin and HA loading using the TNT method provided a novel prophylactic method against prosthetic infections and other biomedical applications