Effect of O₂-plasma treatment on surface characteristics and osteoblast-Like MG-63 cells response of Ti-30Nb-1Fe-1Hf alloy

In this study, the effect of O₂-plasma treatment with various powers on the surface characteristics and also the cell response of the Ti-30Nb-1Fe-1Hf alloy were investigated. Surface characteristics of Ti-30Nb-1Fe-1Hf alloy were evaluated by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray powder diffractometer (XRPD) and wettability test. The results show that the surface roughness of the alloy decreases after O₂-plasma treatment, and also with increased plasma power. By XPS analyses, both Ti valence states of Ti ²⁺, Ti³⁺ and Ti⁴⁺ as well as Nb valence states of Nb²⁺, Nb⁴⁺ and Nb⁵⁺ can be detected in the oxide films. Also, the concentrations of TiO₂ and Nb ₂O₅ increase with increasing O₂-plasma power. The results also show that the contact angle decreases as the alloy is modified by O₂-plasma treatment, and therefore, the treated alloys can be expected to be more hydrophilic. On the other hand, for the evaluation of cell response, cell (MG-63) culture was performed. The results show that the oxidation effect on the alloy surface brought about by O₂-plasma treatment enhances the spreading of cells. In addition, in vitro tests suggest that cell spreading on Ti-30Nb-1Fe-1Hf alloy is similar to that on Ti-6A1-4V alloy, whereas, cell adhesion on Ti-30Nb-1Fe-1Hf alloy is better than that on Ti-6A1-4V alloy.