论文部分内容阅读
One of the key challenges in engineering of orthopedic implants is to "bioactivate" their surface by using different surface techniques and materials.Carbon,especially amorphous(a-C)and diamond-like carbon films(DLC)films have attracted much attention in biomedical fields due to their biocompatibility and low coefficient of friction.However,they are unsuitable for uses as a "bioactivity enhancer" of orthopedic implants due to their bioinermess.In this work,we used a nonreactive magnetron sputtering technique to produce a-C films composited with an biocompatible niobium(Nb)element to alter the surface chemistry and nanotopography of the a-C films with the purpose of bioactivating the a-C film coated implants.The amount of carbon in the film,the grain size and the surface roughness can be controlled by adjusting the powder applied on Nb target.It was demonstrated that addition of Nb into the a-C films not only improved corrosion resistance,but also possess enhanced mechanical properties(nanohardness,Young s modulus and superelastic recovery).Preosteoblasts(MC3T3-E1)cultured on the Nb-C films have enhanced adhesion and upregulated alkaline phosphatase(ALP)activity,compared to those cultured on the a-C film and TiO2 films used as a control,which are thought to be ascribed to the combined effects of the changes in surface chemistry and the refinement of the nanotopography caused by the addition of Nb.