Osteogenic and antibacterial properties of TiN-Ag coated Ti-6Al-4V bioimplants with polished and laser textured surface topography

Abstract

In this study, polished and laser textured Ti6Al4V alloy bioimplant samples were coated with TiN and Ag using PVD technique and evaluated for the synergistic effects of osseointegration and antibacterial behaviour. The surface roughness parameters, surface wettability, XPS, XRD and SEM analysis of the modified surface were carried out. The level of osseointegration of the coated samples was evaluated through in-vitro osteoblast cell adhesion and fluorescent microscopy. The antibacterial property was evaluated through the degree of bacterial adhesion using S.aureus strain. The osseointegration and antibacterial properties are correlated with the physio-chemical characteristics of the coated samples. The results show that the negative skewness value for the case of textured surface is also associated with increased surface roughness in comparison with polished surface. TiN-Ag coated textured samples are hydrophilic in nature due to the increased surface roughness and the presence of metallic oxides with hydrophilic properties at the surface. Both the coated samples have exhibited improved cell adhesion and proliferation with the TiN-Ag coated textured samples showing slightly higher osteointegration together with preferential alignment of cells due to the phenomenon of contact guidance. With regard to antibacterial behaviour also, both the TiN-Ag coated polished and TiN-Ag coated textured samples demonstrated improved performance than its un-coated counterparts. The study revealed that TiN-Ag PVD coating on polished and laser textured Ti6Al4V implant samples is favourable for better osseointegration and antibacterial behaviour of the implants. Also, the laser textured-TiN-Ag PVD coated samples are superior over TiN-Ag coated polished samples with regard to their osseointegration and antibacterial performance.