Bioactive zirconia thin films fabricated by dual cathodic arc and oxygen plasma deposition

The materials surface plays an extremely important role in the response of the biological environment to the artificial medical devices. The initial protein interactions with implant surfaces are very important and therefore, it is clear that if the surface morphology, structure, composition, and properties are changed, cell functions are influenced. Nanoscale materials are thought to interact with some proteins more effectively than conventional materials and to mediate osteoblast functions due to their similar size and altered energetics. In our experiments, nano-structured zirconium oxide thin films are prepared by dual cathode arc and oxygen plasma deposition. The phase composition and structure of the zirconium oxide thin films were determined by X-ray diffraction (XRD), optical absorption spectra (OAS), and atomic force microscopy (AFM). The results reveal that the as-prepared zirconia films possess the primitive tetragonal ph ase. The films are also characterized by scanning electron mi croscopy (SEM) and surface potential analysis. After immersion in simulated body fluid (SBF) solution for a certain period, the nano-structured ZrO₂ thin film can induce bone-like apatite to form on its surface, indicating that the thin film is bioactive. In addition, bone marrow mesenchymal stem cells are found to grow and proliferate in good states on the thin film surface. The zirconia thin films with both superi or bioactivity and cytocompatibility have thus been successfully fabricated and it is believed that nano-structure and surface charge of the thin films play very important roles.