Antibacterial potential of Zn- and Cu-substituted hydroxyapatite-based coatings deposited by RF-magnetron sputtering

The market of medical devices demanding new products for treatment of bone fractures. The demand is growing due to aging population and increased physical activity in senior people. We introduce newly developed implants – intramedullary fixators made from a set of biocompatible alloys including commercially pure titanium, Ti-6Al-7Nb and magnesium-based alloy. Surface of these implants is modified by Zn- or Cu-substituted hydroxyapatites coatings deposited by RF magnetron sputtering in order to diminish the risk of post-operative infection. The amorphous layers were deposited on the surface of biocompatible substrates for all deposition runs. Post-deposition annealing in air at the temperature of 700°C allowed us to crystallize coating in a way that the main hydroxyapatite peaks are well defined and lattice parameters calculated proving Zn²⁺ and Cu²⁺ substitution. The bacteriostatic effect of the coatings against the pathogenic strain 209P of Staphylococcus aureus was shown in vitro independent on the material of the metallic substrate