Antimicrobial surface modification of titanium substrates by means of plasma immersion ion implantation and deposition of copper

Antimicrobial equipped surfaces of titanium (Ti-6Al-4V) implants are beneficial to prevent implant-associated infections of total joint endoprostheses and osteosyntheses. Copper (Cu) is well suited for this purpose, since it exhibits a well-known antimicrobial activity and can be found as a trace element in the human body, i.e. it is nontoxic in small concentrations. For this approach plasma immersion ion implantation and deposition (PIII&D) of Cu into Ti was evaluated. The amount and also the depth-profile of implanted and deposited Cu in and on the surface were analyzed by X-ray photoelectron spectroscopy (XPS) and ball cratering tests. The layer morphology was studied using scanning electron microscopy (SEM). The surfaces released up to 3.2 mmol/l of Cu within 24 h, measured with atomic absorption spectroscopy (AAS). Such Cu doped and coated Ti implants could be useful for prevention and therapy of implant-associated infections.