Tantalum nitride coatings prepared by magnetron sputtering to improve the bioactivity and osteogenic activity for titanium alloy implants

A good orthopedic load-bearing implant should have both excellent mechanical properties and biological activity. In order to improve the biological activity of Ti6Al4V-based implants, tantalum nitride (TaN) films were deposited on the surface of Ti6Al4V alloy and Si(100) substrates by magnetron sputtering. Characterized by XRD and XPS, it was proved that the uniform cubic NaCl-structure TaN films were successfully prepared on the Ti6Al4V alloy substrate. The TaN film showed higher hardness (19.7 GPa) and elastic modulus (254.4 GPa) compared with HA coatings and Ti6Al4V alloys. We evaluated cytocompatibility and osteogenesis activity of the TaN coatings using rabbit bone marrow stromal cells (BMSCs) cultured on the coated and uncoated samples. The biocompatibility of the films and their effect on cell proliferation were examined by live/dead cell staining and CCK-8 assay. SEM and cytoskeleton fluorescent staining were used to observe the cell adhesion and morphology on different samples. The effect of the film on osteoblastic activity was assessed by calcium nodule staining and alkaline phosphatase quantitative assays. We demonstrate that TaN film can enhance the adhesion, proliferation, and differentiation of BMSCs. These results suggest that TaN film prepared by magnetron sputtering has great potential to be applied in orthopedics.