Comparative Study of Drug Elution Profiles from Femtosecond Laser-Fabricated Micro/Nanostructures on Ti-6Al-4V and TiNbZrSn for Orthopedic Implants

Controlled local drug delivery from orthopedic implants is a promising strategy for reducing post-surgical infections and enhancing early-stage healing. In this study, a comparative investigation of drug elution behavior from femtosecond laser–fabricated micro/nanostructures on Ti-6Al-4V and TiNbZrSn alloys is presented. Ultrafast laser processing was employed to generate hierarchical surface features with comparable roughness scales on both substrates while preserving their bulk properties. A model antibiotic was subsequently loaded onto the laser-textured surfaces, and in vitro release kinetics were evaluated under physiological conditions. The results reveal distinct elution profiles between the two alloys, attributed to differences in surface chemistry, oxide composition, and wettability induced by laser structuring. TiNbZrSn surfaces exhibited more sustained release behavior, whereas Ti-6Al-4V showed a relatively higher initial burst. The findings highlight the role of alloy composition in modulating drug–surface interactions on laser-engineered implants. This comparative insight supports the rational selection and surface design of titanium-based biomaterials for infection-resistant and therapeutically active orthopedic implants.