Electrochemical-antimicrobial coating on layer-by-layer for dental implants: cationic surface treated by plasma electrolytic oxidation for drug delivery treatment

Abstract

Peri-implant infections and electrochemical degradation of titanium (Ti) are the main causes of failure in dental implant therapies. In this perspective, our previous study demonstrated that cationic coating is promising due to its antimicrobial activity and increased corrosion resistance on Ti surfaces. Thus, using this newly developed cationic coating as an alternative route for self-assembly layer-by-layer (LbL) coating with controlled drug release seems to be an interesting strategy, as it would be one more protective layer (antimicrobial and anticorrosive), since the LbL system can be degraded, and drug release is affected over time. Therefore, this project aims to develop a three-step LbL self-assembly coating: 1) obtaining a positively charged surface by means of a cationic coating. For this first step, it will be obtained by means of plasma electrolytic oxidation (PEO+OH) and followed by silanization (aminopropyl-triethoxysilane; APTES); 2) intercalated multilayers of poly(acrylic acid) (PAA) and poly-l-lysine (PLL), forming one coating on the other by electrostatic interaction; 3) deposition of tetracycline (TC). The surface characteristics, mechanical, physicochemical, tribological, electrochemical, antimicrobial, biological, and osteogenic properties of the coating will be investigated. For this, commercially pure titanium (Ticp) disks with different treatments will be used:: 1- machined and polished (Ti; material control); 2- LbL coating (LbL; control of experimental 1); 3 - cationic coating via PEO (RCP) (RCP; first control of experimental 2); 4 - LbL coating via RCP (RCP+LbL; second control of experimental 2); 5 - LbL + TC coating (LbL+TC; experimental 1) and 6- LbL coating via RCP + TC (RCP+LbL+TC; experimental 2). Surface characteristics and mechanical properties will be evaluated by physical and tribological tests, respectively. Also, the electrochemical behavior will be performed to measure the corrosion resistance of the treatments. The antimicrobial potential of the film against monospecies and polymicrobial biofilm will be evaluated in vito and in situ. The interaction of the surfaces will be analyzed for protein adsorption and cytocompatibility. The data will be submitted to the most appropriate statistical analysis considering ± = 0.05.