Development and in vivo validation of a novel triggered release antibiofilm coating for orthopaedic implants and vascular grafts.

• Hans Steenackers, Katholieke Universiteit Leuven, Belgium (Coordinator)
• Stephan Zeiter, AO Research Institute Davos, Switzerland (Partner)
• Annette Moter, Charité University Medicine, Germany (Partner)

One of the most challenging problems related to implanted medical devices is the high prevalence of microbial infections. Previous studies showed that implant-related infections are typically caused by biofilm forming microbes. In contrast to infections caused by free-floating microbes, biofilms generally increase the tolerance to antimicrobials and increase the risk for antimicrobial resistance development. The TRA-COAT project aims to address the incidence of implant infections by developing a novel, resistance-proof antimicrobial coating with innovative functionalities, including anti-biofilm activity and triggered release of classic antimicrobials. The focus will be on orthopaedic trauma implants and vascular grafts, but can later be applied to other implants. The coating will combine a covalently bonded biofilm inhibitor and a reversibly bonded classic antimicrobial. The action of the inhibitor will reduce the slimy matrix production during biofilm formation which will allow the immune system to better remove the microorganisms. If remaining biofilm should still occur, growth of the bacteria on the surface will locally trigger release of the antimicrobial, killing the pathogens. The coating is designed to be resistance-proof. Indeed, the biofilm inhibitors are intrinsically robust to resistance and will enhance the effectivity against the classic antimicrobial, as such also reducing the risk for resistance against the latter. The local and time-restricted release of the antimicrobial will moreover further reduce the risk of resistance development.