Preparation And Characterization Of DLC/CPP On The Surface Of Titanium Alloy

Titanium (Ti) and its alloys are widely used as metallic biomaterials for fabrication of dental and orthopedic implants, owing to their good mechanical, chemical properties, and favorable biocompatibility in a body environment. However, the bioactivity of the titanium alloy is not good enough to form chemical combination to surrounding tissue. In addition, the poor tribological properties are their disadvantages, which hindered its further application and effect as a biomaterial. Therefore, it is necessary to modify the surfaces with proper methods and materials.In this paper, in order to enhance the bioactivity and tribological properties of the titanium alloy, we deposited Diamond-Like Carbon (DLC) films on Ti-6Al-4V substrates, and then used polydopamine as the interlayer to immobilize the Casein phosphopeptides (CPP) onto the DLC films via biochemical multistep self-assembled method. Firstly, the structure and composition of the prepared films were characterized by Raman spectra, X-ray photoelectron spectroscopy (XPS) and contact angle measurement. Secondly, the tribological properties were investigated by UMT-2MT. Finally, the cytocompatibility of the DLC/CPP composite film were evaluated by osteoblasts.The Raman show that the DLC films were successful preparation on titanium alloy surfaces, the XPS indicates that the film composition and the chemical states of the elements were changed in each successive step. The friction coefficient is reduced from0.236to0.084, and the wear rate reduced from4290×10-17m3/Nm to3.886×10-17m3/Nm. Comparing with control group, the adhesion and proliferation of osteoblasts on the DLC/CPP composite film were significantly increased. All the above, the titanium alloy coated by DLC/CPP has significantly the tribological properties and cytocompatibility, and it might be widely useful in clinical applications as biological implant materials.