Micro/nano scale modification of titanium surface for enhanced mesenchymal stem cell interactions and antibacterial properties

Abstract

Titanium has been established as the gold standard for fabrication of implants for orthopedic purposes thanks to their excellent mechanical properties, great corrosion resistance and biocompatibility. However, titanium is bioinert which leads to insufficient osseointegration, leading to implant loosening, bacterial infection and ultimately, implant failure. Better osseointegration can be achieved by fabricating surfaces which are able to better integrate with the tissue whilst preventing bacterial infection. Additionally, blood clotting, while also being the first step of wound healing process, has also displayed enhanced bone formation. Therefore, the surfaces should also be able to encourage blood clotting. To address these challenges, two different surface modifications on titanium were investigated in this dissertation. The first was a fabrication of copper modified titania nanotube surfaces (NTCu). The second approach was nanostructured-micro-porous titanium surfaces (NPTi). The hemocompatibility and ability of the surfaces to promote cell adhesion, growth and differentiation as well as prevention of bacteria adhesion and biofilm formation were investigated. The results indicated that both the surface modifications possess enhanced antibacterial properties, improve cell differentiation to osteogenic lineages and that the NPTi surfaces displayed enhanced blood clotting characteristics, hence being a potential approach for designing orthopedic implants.