Influence of content of silicon nitride nanoparticles into micro-arc oxidation coating of titanium on bactericidal capability and osteoblastic differentiation

Abstract

Bone implants with osteogenic and bactericidal capability are particularly promising for orthopedic applications. Herein, micro-arc oxidation (MAO) coatings containing silicon nitride (Si3N4) on titanium (Ti) surface (MSN) were fabricated by dispersing different content of Si3N4 nanoparticles in the electrolyte. Compared with pure Ti and MAO coating, incorporation of Si3N4 nanoparticles into the MAO coating caused significant change in surface characters (e.g., nano-topography, hydrophilicity and surface energy) of MSN, and the change depended on the content of Si3N4 nanoparticles. MSN with the changed surface characters exhibited remarkable improvement of cell response (e.g., multiplication and osteoblastic differentiation), which significantly enhanced with the increase of Si3N4 content. Furthermore, MSN displayed excellent bactericidal ability, which improved with the increase of Si3N4 content. As a result, the enhancements of cellular response and bactericidal capability were ascribed to the increase of Si3N4 content in the coating, and MSN with high content of Si3N4 possessed outstanding osteogenic and anti-bacterial effects. The study demonstrated that incorporation of Si3N4 nanoparticles into the MAO coating led to novel implantable materials of MSN, which exhibited excellent cytocompatibility, osteogenic bioactivity, bactericidal ability, suggesting that MSN possessed a promising potential for applications in orthopedics.