Surface Functionalization of Titanium for the Control and Treatment of Infections

Titanium and its alloys are widely used as implant materials owing to their good mechanical properties and tissue compatibilities. Biomaterial-associated infections caused by biofilm formation are a major cause of failure of implant surgeries. Antibacterial biomaterials prevent biofilm formation at its initial stages. Titanium surfaces can be functionalized with various coating technologies to achieve antibacterial or anti-biofouling properties. In this chapter, we will describe titanium, biomaterial-associated infections, and therapeutic strategies using coating technologies and also focus on the use of micro-arc oxidation to prevent infections. Micro-arc oxidation is a conventional wet process involving electrochemical treatment with a specific electrolyte solution under high voltage, enabling the formation of a porous oxide layer on titanium surfaces owing to a micro-arc resulting from the dielectric breakdown of the titanium dioxide layer. This process can potentially help incorporate calcium and phosphorous ions into the surface layer by controlling the composition and concentration of the electrolyte. Micro-arc oxidation has already been used for titanium implants to promote hard-tissue compatibility. Since 2008, titanium surfaces have been modified by micro-arc oxidation treatment using an electrolyte with antibacterial elements such as silver, copper, and zinc to achieve an antibacterial property and biocompatibility on the titanium surface. In particular, the prevention of infectious diseases can be achieved by using micro-arc oxidation to design antibacterial biomaterials and alter the compositional control of the titanium surface.