Plasma and ion beam modification of metallic biomaterials for improved anti bacterial properties
Abstract Plasma based technology is effective in improving the performance of titanium and magnesium based biomaterials with regard to bacteria prevention and osteogenetic induction. For titanium and titania, silver ion implantation can endow them with good bactericidal ability without compromising the compatibility with osteoblast cells and sometimes even improve the biological functions. In Ag implanted titanium, micro galvanic effects occur between the Ag nanoparticles and titanium substratum forming a proton depleted region which may cause bacteria death due to the disturbance of their energy production process. In ion implanted titania, the electron storage ability of the nanoparticles may facilitate electron transfer between titania and bacteria membranes resulting in bacteria death. These reactions involve a very small amount of released Ag ions thus simultaneously favoring cell growth, proliferation, and differentiation. With respect to biodegradable magnesium and magnesium alloys, ion implantation can achieve the balance between corrosion protection and bacteria prevention. Ion implantation of the suitable elements followed by O ion implantation produces a dense metal oxide layer on the surface to protect the materials from rapid corrosion. As an example, the effects of Zr on the bacteria adhesion and cyto compatibility of Mg are described. Abstract code: P8