Antimicrobial Potential of Copper‐Containing Titanium Surfaces Generated by Ion Implantation and Dual High Power Impulse Magnetron Sputtering

Abstract

The application of antimicrobial surfaces to titanium alloy (Ti) implants would be beneficial to prevent implant‐associated infections of joint endoprostheses and osteosyntheses. Copper (Cu) could be advantageously applied for this purpose, since it exhibits a well‐known antimicrobial activity and is a trace element in the human body, i.e., it is non‐toxic in small concentrations. This approach was evaluated with two plasma‐based surface modification procedures: Implantation of Cu ions into Ti by means of plasma immersion ion implantation (PIII) and Coating of Ti surfaces with CuTi films by means of dual high power impulse magnetron sputtering (dual HiPIMS). In this manner, the surfaces could be equipped with various amounts of Cu, as it was analyzed by X‐ray photoelectron spectroscopy (XPS). The surfaces released up to 8 mmol · L−1 of Cu within 24 h, measured with atomic absorption spectroscopy (AAS). Hence, the surfaces possessed an antimicrobial potential against typical infect‐associated bacteria (Staphylococcus aureus). Surfaces with a higher Cu release prepared by HiPIMS technique revealed a higher antimicrobial effect, while surfaces implanted by PIII were less cytotoxic to osteoblasts (MG‐63 cells). These results show that Cu doped and coated implants could be useful for prevention and therapy of implant‐associated infections.

Cold Physical Plasmas in the Field of Hygiene—Relevance, Significance, and Future Applications

“…Third, plasma processes at low or atmospheric pressure can facilitate the deposition of composite coatings with hydrophilic matrices embedding bioactive or microbicidal molecules . For example, an allylamine plasma polymer film can immobilize silver nanoparticles or titanium–copper layers on surfaces . These plasma coatings can be applied to many types of materials, thereby generating vast opportunities to develop, for instance, antimicrobial implants or antiseptic wound dressings and surgical sutures.…”

Plasma Processes and Plasma Sources in Medicine

“…Using a method called metal plasma immersion ion implantation (MePIII) it is possible to dope the subsurface of the medical implant with copper. [30]. The positive (copper) ions in the gas discharge are accelerated in the electrical field towards the implant.…”

“…However, by adjusting the absolute amount of copper and the copper release from the surface, a surface functionalization that only slightly influences the cell vitality but has a good antibacterial effect can be achieved. [30].…”

Influence of Cu–Ti thin film surface properties on antimicrobial activity and viability of living cells

“…A number of implant surface modifications have been developed to inhibit bacterial colonization by release of bactericidal agents. For example, it was found that sufficient and long lasting copper release is needed to inhibit and neutralize all bacteria (more resistant biofilm) [24][25][26].…”