Evaluation of chlorhexidine /polydopamine antimicrobial coatings on the Ti-7.5 Mo alloy surface - in vitro studies

Titanium and its alloys are widely used in biomedical applications because of their excellent properties such as high corrosion resistance, biocompatibility and mechanical properties. One of the applications is in dental implants and usually presents failures due to infectious processes caused by the formation of a biofilm layer on the implant surface. The biofilm structure makes it difficult to treat these infections, leading to the development of new surface modification techniques, in order to prevent the adhesion of microorganisms to the implant surface. The objective of this study was to evaluate the efficiency of a Ti7.5Mo alloy surface coating with a natural polydopamine (PDA) polymer associated with a bactericidal agent, chlorhexidine (CHX). The surfaces were characterized using contact angle (AC) and surface energy. Cytotoxicity using adipose derived stem cells and antibacterial behavior using Staphylococcus aureus and Candida albicans were evaluated. Both groups coated with this antibacterial system acted efficiently in combating the formation of C. albicans and S. aureus biofilms without causing cytotoxic effect on stem cells derived from adipose tissue. Therefore, the coating of the Ti-7.5Mo alloy with polydopamine and chlorhexidine is a promising application for biomedical devices aimed at reducing the formation of biofilms and, consequently, the reduction of postoperative infections.