Preparation Of Micro Porous TiO2/MOF Composite Coating For Photodynamic Antibacterial And Bone Repair

After the implantation of medical titanium-based materials,the bacterial infection in the early stage and the lack of bone repair ability of the materials in the later stage are two important reasons for the failure of clinical implantation.Therefore,the preparation of a titanium-based metal material with controllable antibacterial activity in the initial stage and excellent bone repair activity in the later stage has positive practical significance in clinic.Based on this situation,a multi-functional composite coating was prepared on titanium surface,which has good visible light controllable antibacterial and bone repair properties.In this paper,the structure and composition of the coating were studied,the relationship between the light response of the coating and the production of reactive oxygen species（ROS）was explored,and the composite coating was applied to antibacterial and bone repair applications.It mainly includes the following two parts:1.A composite coating with light-controlled antibacterial and bone repair properties was prepared.Firstly,micron porous titanium dioxide（Ti O₂）was prepared on titanium surface by micro-arc oxidation,and then polydopamine（PDA）coating was prepared on Ti O₂surface.PDA on the surface of Ti O₂was used to induce the formation of iron-based porphyrin metal organic framework（Fe-MOF）to obtain Ti O₂/PDA/Fe-MOF（Ti O₂-P-F-M）coating.Finally,bone morphogenetic protein-2（BMP-2）was loaded into the composite coating.The Ti O₂/PDA/Fe-MOF/BMP-2（Ti O₂-P-F-M-B）composite coating has good mechanical stability and good biocompatibility.2.It was found that the combination of Fe-MOF and Ti O₂could reduce the recombination ratio of photogenerated electron holes at 650 nm wavelength,thus increasing the yield of singlet oxygen in ROS and increasing the antibacterial rate.The bone marrow mesenchymal stem cells（BMSC）were inoculated on the material for biological activity evaluation.The results showed that the composite coating could effectively promote cell proliferation and differentiation.The antibacterial experiment showed that the composite coating produced good synergistic antibacterial activity under the irradiation of visible light.The in vivo shows that the composite coating has good bone repair performance.To sum up,in this study,a multi-functional coating with both light-controlled sterilization and bone repair properties was prepared on titanium surface.This study provides a new idea for the research and development of antibacterial and bone repair medical devices.