Antibacterial properties of copper-tantalum thin films: The impact of copper content and thermal treatment on implant coatings

This study evaluates the antibacterial properties and physicochemical characteristics of -tantalum-copper (Ta-Cu) coatings deposited on titanium alloy substrates using high-power magnetron sputtering. Implant-associated infections, particularly those caused by bacterial adhesion and biofilm formation, pose significant challenges in the field of orthopedic and dental implants. To address these issues, Ta-Cu coatings with varying copper content (∼3.0 wt%, ∼10 wt%, ∼17 wt% for TaCu-1, TaCu-2, and TaCu-3, respectively) and different thermal treatment conditions (400 °C, 500 °C, 600 °C) were assessed for their antibacterial efficacy against <i>Escherichia coli, Staphylococcus aureus, Salmonella enterica,</i> and <i>Pseudomonas aeruginosa</i>. The study utilized both the diffusion into agar method and the time-kill test to evaluate antibacterial activity. Results indicate that the TaCu-2 sample, particularly when annealed at 600 °C, demonstrated the highest bactericidal activity, especially against <i>E. coli</i> and <i>P. aeruginosa</i>. The findings highlight the critical role of optimizing both copper content and annealing temperature in enhancing the antibacterial properties of Cu-Ta coatings, making them promising candidates for preventing implant-associated infections.