Preparation And Biocompatibility Of DLC With Substrate Blasting And Nitrogen-doped Pretreatment

Aims:DLC was prepared on the surface of different roughness and the nitrogen-doped diamond-like carbon film on Ti6A14V alloy by using plasma enhanced chemical vapor deposition (PECVD) technique, and their biocompatibility was also studied.Materials and methods:DLC was deposited on titanium alloy plate with different roughness produced by the sand blasting using Al2O3 particles of different sizes under the same condition. The surface morphology, wettability, chemical composition, the adhesion strength between DLC and substrate, and the electrochemical corrosion behavior of each group were characterized. The biological behavior was also evaluated by the methods of MTT and fluorescent staining. The nitrogen-doped diamond-like carbon film was prepared on Ti6A14V alloy by PECVD technique. The surface morphology,chemical composition and contact angle were measured, and its biocompatibility was studied as well.Results:1. The DLC deposited on the sandblasting titanium alloy plate substrate has been successfully prepared. The surface of sandblasting groups (S36,S60,S120,S280) shows the irregular concave and convex structure. After the sand blasting, all the contact angle (<90°) increased with the increase of sand diameter, indicating high hydrophilcity. Meanwhile, sandblasting substrate can markedly enhance the adhesion strength between DLC and substrate, which can reaches 45N for the S60 group, so this value is higher than other experimental groups. Moreover, the DLC on the titanium alloy can protect it from electrochemical corrosion owing to the corrosion potential increase compared to the untreated group.In addition, experimental groups showed higher cellular survival rate than the control group.2. The nitrogen-doped diamond-like carbon film was prepared on Ti6A14V alloy by using plasma enhanced chemical vapor deposition (PECVD) technique. The surface of DLC and DLC doped with Nitrogen groups (DLC:N) was smooth. By the analyses of the Raman and XPS, DLC:N containing 5% N element completely covered on the Ti substrate. The results of water contact angle showed that the surface of DLC:N was more hydrophilic than that of the DLC group, and the contact angle decreased from 84.89° to 70.49°. Moreover, the cell adhesion and proliferation could be significantly promoted on DLC:N.Conculsion:The results clearly clearly show that the methods of sandblasting substrate arid nitrogen-doped can improve the biocompatibility of materials, and also benefit cell growth. So both methods are useful to modify titanium alloy, and have the potential application in clinical.