Preparationand Characterization On The Surface Of Stainless Steel With Chitosan/Hydroxyapatite

The medical 316 L stainless steel is widely used in the biomedical field,especially used of orthodontic micro screw.because of its excellent mechanical and mechanical properties,good biocompatibility and low processing cost.However,the higher micro-screw around inflammation is the main reason caused by orthodontic micro-screw implant shed.This study is for control the micro-screw aroundinflammation,toimprove 316 L stainless steel surface of the antibacterial modification,for its further application in orthodontic treatment.Objective: To prepare a composite coating containing chitosan/ hydroxyapatite on the surface of medical 316 L stainless steel to improve the antibacterial properties of medical 316 L stainless steel.Methods: Chitosan/ hydroxyapatite composite coating was prepared on the surface of medical 316 L stainless steel by electrodeposition.Experimental parameters: voltage: 10 V,pulse width: 7200s;solvent: water: ethanol = 1: 1.Different chitosan/ hydroxyapatite composite coatings were prepared by using different amounts of hydroxyapatite and different quality chitosan as solute to prepare different concentrations of electrolyte.The chemical composition,phase structure and surface morphology of the composite coatings were characterized by X-ray spectroscopy,X-ray diffraction,scanning electron microscopy and Fourier transform infrared spectroscopy.The biocompatibility was observed by MTT and cell morphology.The antimicrobial properties were evaluated by antimicrobial experiments.Results: The chitosan/ hydroxyapatite composite coating was successfully prepared on the surface of medical 316 L stainless steel.SEM shows that with the increase of chitosan concentration,the larger the surface pores of the composite coating,the thicker the film layer;The EDS shows that the surface of the composite coating is rich in Ca,P,N,O,C and other elements.FTIR shows that the complex coating is rich in-NH2,PO43-and other functional groups.XRD shows that there is obvious hydroxyapatite peak in the composite coating,and the characteristic peak of hydroxyapatite decreases with the increase of chitosan concentration.MTT test and antibacterial test results show that the chitosan concentration of 0.5g / L,hydroxyapatite concentration of 3g / L when the composite coating the best biocompatibility,antibacterial effect is significant,the antibacterial rate of 95%.Conclusion: The chitosan/ hydroxyapatite composite coating prepared by electrodeposition on the surface of 316 L stainless steel can effectively improve the antibacterial property of 316 L stainless steel.And provide the theoretical basis for the application of antibacterial 316 L stainless steel micro screw implant in clinical practice.