Recent advances on the antibacterial coating on titanium implant by micro-Arc oxidation process

Titanium (Ti) and its alloy are widely used for artificial joints, dental implantations, orthopedic and bone screws because of their good biocompatibility, magnificent mechanical properties, and great corrosion resistance. As the Ti is bioinert and lacking antibacterial properties, which impact the use of such materials in the field of biomedical applications. When microorganisms attached to the surface of biomaterials it will start the implant related infection, which is a serious clinical issue. Infection frequently begins with bacterial attachment to the implant surface, after that colonization of bacteria started on the implant surface, once the colonization increases to larger extent it forms the biofilm. Once biofilm form, it becomes remarkably impervious to antibiotics and the host immunity defensive system to eliminate the biofilm from implant surface which prompting further complexities. The counteraction of biofilm development by antimicrobial surfaces is the most ideal approach to avoid both the spread of microorganisms and material decay. Antibacterial coating on implant surface is a convincing method to decrease the event of implant related infections. Among available methods micro arc oxidation (MAO) is profoundly reasonable for the development of bioactive and antibacterial coatings on titanium implant. In this paper antibacterial mechanism some of nanoparticles such as Zn, Ag, Cu, and AgO when incorporated in MAO coating is discussed. It was observed that antibacterial activity of silver nanoparticles is due to combination of contact killing and release of Ag nanoparticles, as well as the arrival of Ag+ ions from the coating surface to the electrolyte solutions. Zn coating can restrain bacterial development by producing responsive oxygen species (ROS). ROS is bacteria harmful species. In Cu nanoparticles incorporated antibacterial coating, bacteria absorbed Cu ions and resulted into the formation of cavities in the cell wall of bacteria through interaction with Cu ions.