Enhancing the biocompatibility of ZrO2 thin film on Zr-2.5Nb alloy by anodizing treatment using an electrolyte containing biofunctional groups

Abstract

Surface characteristics of a biomaterial such as morphology, topography, and chemistry influence cell attachment, proliferation, gene expression, and differentiation. Studies have shown that anodizing, one of the most effective electrochemical surface modification methods, could improve cell to implant surface interactions. In this study, the Zr-2.5Nb alloy was anodized in an aqueous electrolyte containing CaF2 and NH4H2PO4. The effect of anodizing treatment on the surface modification of Zr-2.5Nb was also investigated. The biocompatibility of the non-anodized and anodized specimens was evaluated by the MG-63 osteoblastic cells. The results demonstrated that Zr oxide on the anodized Zr-2.5Nb surface consisted of monoclinic and tetragonal structures. Also, the average thickness of the anodic film was measured at about 85 nm, and the electrolyte's fluorine, calcium, and phosphorus ions were incorporated at the top surface of the film. The potentiodynamic polarization and electrochemical impedance spectroscopy tests proved that the anodized specimens exhibit higher corrosion resistance in Ringer's solution than that of the non-anodized specimens. In terms of cell response, MG-63 cells depicted a suitable cell attachment after five days from cell culture as osteoblastic cells showed an excellent proliferation and viability on the anodized specimens. Finally, remarks suggest that anodizing treatment by an electrolyte containing biofunctional groups could enhance the corrosion resistance and cellular performance of the Zr-2.5Nb alloy for biomedical applications.