Ortopedik uygulamalar için tantal yüzeylerin anodizasyon yöntemi ile modifiye edilmesi

Tantalum has excellent corrosion resistance and mechanical properties suitable for orthopedic applications. However, tantalum exhibits bioinert characteristics and cannot promote desired level of osseointegration with juxtaposed bone tissue. To enhance the bioactivity of tantalum, nanoscale surface modification via anodization could be a potential approach. In this study, tantalum foils were modified to obtain surface features with different morphologies, i.e. nanotubular, nanodimple, nanoporous and nanocoral, via anodization. By controlling anodization parameters including voltage, anodization duration, temperature and electrolyte concentration, surface feature sizes were precisely fine-tuned in the range of 20 -140 nm. In this thesis, anodized tantalum samples were characterized to investigate physical and chemical properties of their surfaces, i.e. morphology, crystallinity, hydrophobicity, topography and chemistry. The results indicated that anodized tantalum surfaces consisted of Ta2O5 and non-stoichiometric tantalum oxide (tantalum sub-oxide). Upon the anodization, surface area of the tantalum samples increased up to 2 folds, which was accompanied by up to 3.5 folds increase in the nanophase surface roughness. Preliminary studies were completed by assessing the interaction of nanoporous tantalum surfaces with fibroblast cells. It was observed that nanoporus tantalum enhanced fibroblast proliferation and spreading in vitro. In line with that study, anodized nanotubular, nanodimple and nanocoral tantalum and non-anodized tantalum surfaces were interacted with bone cells in vitro. Biological studies showed that anodized tantalum surfaces significantly enhanced protein adsorption and, at the same time, improved bone cell proliferation and spreading in vitro independent of the anodized surface morphology and feature size.