TiO2 nanotubes based composite layers for biomedical applications
|Agata Roguska 1,2, Marcin Pisarek 1,2, Malgorzata Lewandowska 1, Krzysztof J. Kurzydlowski 1|
1. Warsaw University of Technology, Faculty of Materials Science and Engineering (InMat), Wołoska 141, Warszawa 02-507, Poland
Titanium when used in orthopaedic devices and oral implants was considered to be inert. However, recently, it has been shown that it can be toxic or induce allergic reactions. It is possible for the biological properties of titanium to be improved by the application of appropriate surface treatments. The aim of this was to develop methods to modify the surface of titanium, which would allow precise control of its morphology and chemical composition, and achieve beneficial biomedical properties. To achieve this objective a two-step procedure for surface modification was introduced. In the first step the Ti substrates were electrochemically pretreated in solutions containing fluoride. These processes produced specific surface morphology, namely nanotubular structure. In the second stage, biomimetic calcium phosphate (Ca-P) coatings were formed on the nanoporous titanium oxide layer by immersion of the pretreated Ti in simulated body fluid (Hanks’ solution). The results revealed TiO2 nanotubes provided beneficial substrates for the deposition of a uniform Ca-P coating. The main component of coating was octacalcium phosphate, which is considered to be a precursor for the in vivo formation of hydroxyapatite. The preliminary results of the U2OS cells response to the modified surfaces indicate that the number of cells on the TiO2 nanotubes possessing the deposited Ca-P coatings is distinctly higher than for an unmodified Ti surface. In addition, the albumin preadsorption on the Ca-P coating was shown to give further improvement of the adhesion of the osteoblast-like cells. In order to minimize the likelihood of biomaterial induced infections the TiO2 nanotubes layers were loaded with silver nanoparticles using a sputter deposition technique. The presence of Ag nanoparticles on the TiO2 nanotube layers led to a significant reduction in the adhesion of S. epidermidis cells and biofilm formation on the surfaces. Additionally, the Ag/TiO2 nanotubes composite layers were shown to have a positive effect on the adhesion and differentiation of the osteoblast-like cells. The proposed titanium surface modification procedure may be a promising method for fabricating novel materials for internal applications so that components to meet the physical functional requirements maintain biocompatibility and, very importantly, prevent infection.
Presentation: Poster at Nano-Biotechnologia PL, by Agata Roguska
See On-line Journal of Nano-Biotechnologia PL
Submitted: 2012-06-27 13:34 Revised: 2012-09-15 19:46