Bacterial colonization of the biomaterials placed in the human body and resulting inflammation of the surrounding tissues induced a need for development of methods of the surface modification of the implant materials aimed at obtaining an antibacterial effect. Micro-arc oxidation (MAO) turned to be very popular due to its versatility, control-ability and environmental-friendliness. Simplicity in controlling the electrolyte components makes the incorporation of antibacterial agents possible. Nanoparticles (metallic and ceramic) gained in importance out as a large surface-area-to-volume ratio allows substantial amounts of ions of antibacterial additive to be released with the aim to interact with the outer membrane of the bacteria and subsequently with its DNA causing a disruption of its functioning. Even if many literature reports confirmed considerable antibacterial effect of the MAO coatings with selected nanoparticles, their microstructure formation remains sparsely investigated.

In this work, titanium of commercially purity, subjected to hydrostatic extrusion, has been micro-arc oxidized in the electrolyte bath containing sodium phosphate and as-supplied nanoparticles or acetates to produce titania coatings with embedded nanoparticles. In this way, metallic and ceramic nanoparticles have been incorporated. The application of the substrate material presenting a significant anisotropy additionally influences the microstructure formation. Advanced methods of scanning and transmission electron microscopy were used in order to optimize MAO fabrication process and unveil the mechanisms of incorporation of antibacterial additions into the coating.

Acknowledgements

This research was done in the frame of the project funded by the National Science Center of Poland, grant number UMO-2020/39/D/ST8/01783.