Structural, cell culture, antibacterial and in vitro bioactivity analysis of highly-ordered Al2O3 nanotube coating with decorated Ag2O nanoparticles on Ti-6Al-4V

Abstract

The alumina nanotubular arrays (Al2O3 NTs) are a promising candidate for application in bone and dental implants for their better mechanical and chemical behavior in the human body compared to titanium. Nevertheless, the biocompatibility and antibacterial activity of Al2O3 NTs still need further improvement to meet the requirements of safe implants. In this research, Al2O3 NTs coating was proposed on Ti-6Al-4 V via magnetron sputtering pure aluminum followed by an anodization and sealing process, then heat treated for 1 h at 450 °C. After that, Ag2O nanoparticles (NPs) were decorated on the nanotubular walls under controlled conditions using magnetron sputtering. The findings demonstrated that the proposed Al2O3 NTs-Ag2O NPs promoted in-vitro bioactivity alongside excellent antibacterial activity against E.coli and S.aureus bacteria within 4 h and 6 h, respectively. Additionally, the cell-culture showed healthy growth of the human osteoblast cells (HOb) on the Al2O3 NTs-Ag2O NPs. The new design of coating also shows that the total cumulative Ag+released after 14 days is significantly low which is safe and provides the long-term antibacterial activity. It is illustrated that Al2O3 NTs-Ag2O NPs have promising biomedical properties to enhance the biofunctionality of biomedical-grade Ti-6Al-4 V implants.