Postoperative infections associated with orthopedic and biomedical implants represent a major clinical challenge, leading to prolonged recovery times, implant failure, and increased healthcare costs. These complications are largely driven by bacterial adhesion and biofilm formation on implant surfaces, which significantly reduces the effectiveness of conventional antibiotic treatments. Among the most clinically relevant pathogens, Staphylococcus aureus is a major concern due to its high affinity for metallic implants and its ability to form resistant biofilms.

Although titanium-based alloys exhibit excellent biocompatibility and corrosion resistance, they lack intrinsic antibacterial functionality. In this context, TiO₂ nanotubes have emerged as promising platforms for localized drug delivery; however, their performance depends strongly on nanotube architecture and release behavior. This study demonstrates the functionalization of TiO₂ nanotubes on a Ti-24Zr-10Nb-2Sn alloy, a low-modulus Ti-based alloy designed for biomedical applications, to achieve localized antibacterial activity.

TiO₂ nanotubes were fabricated via electrochemical anodization (30 V for 30 min) and evaluated as a gentamicin delivery system. The nanotubes exhibited an average length of 9.92 µm, a diameter of 80.67 nm, and a high surface density (~195 nanotubes/µm²), enabling efficient drug loading.

Drug release analysis revealed a biphasic profile, with an initial release of 54.47% within 40 min, followed by complete release at 120 min, suggesting diffusion-mediated release from the nanotubular structure. Antibacterial assays showed a significant reduction in viable bacteria (~17 CFU/mL) compared to untreated controls (>300 CFU/mL) (p < 0.05). Additionally, agar diffusion tests revealed a large inhibition zone of 49.6 mm, confirming effective antibiotic release and diffusion.

These findings demonstrate that anodized TiO₂ nanotubes provide an effective localized antibiotic delivery system, offering a promising strategy to mitigate implant-associated infections through rapid antibacterial action.