Biological Behavior of Osteoblast-like Cells on Titania and Zirconia Films Deposited by Cathodic Arc Deposition

Cathodic arc deposition technique was used to deposit zirconia (ZrO2) films and titania (TiO2) films on titanium (Ti) disks respectively. The surface topography was characterized by scanning electron microscopy and atomic force microscopy. The element composition of the films was detected by X-ray photoelectron spectroscopy. The phase of films was identified by thin film X-ray diffraction. The biological behavior of osteoblast-like MG63 cells cultured on Ti, TiO2 and ZrO2 was investigated and the possible signaling molecules involved was studied by the gene expressions of integrin β1, extracellular related kinase 1/2 (ERK1/2), and c-fos. The results indicated that both the TiO2 and ZrO2 films were amorphous. Scanning electron microscopy study showed that the adhesion of MG63 cells on TiO2 and ZrO2 films was significantly enhanced compared to Ti. The CCK8 assay indicated that the TiO2 and ZrO2 films promoted the proliferation of MG-63 cells. The alkaline phosphatase (ALP) activity test and the production of type collagen I (COLI) by immunofluorescence showed that both the TiO2 and ZrO2 films can enhance ALP activity and COLI expression of MG-63 cells. In addition, the ALP activity on ZrO2 films was higher than on TiO2 films at day 4, which indicate ZrO2 films may lead to promotion of a more osteoblastic phenotype of MG-63 cells than TiO2 films. Real-time polymerase chain reaction analysis demonstrated that The gene expression of integrin β1, ERK1/2, and c-fos was higher on TiO2 and ZrO2 films than on Ti. The present work suggests that the amorphous ZrO2 films produced by cathodic arc deposition may be favorable for orthopedic implant applications and worth further study.