Biocompatibility And Antibacterial Activity Of A New Type Of Copper-loaded Titanium Dioxide Composite Coating

Objective:To prepare a novel copper-loaded titania composite coating on the surface of pure titanium by sandblast etching,secondary anodic oxygen and electrodeposition of copper,and study its influence on the proliferation,adhesion of osteoblasts,etc.The antibacterial properties of the composite coating in order to find a suitable copper concentration provide scientific basis for further animal experiments and clinical applications.Methods:Different copper concentration test specimens were used as the study objects.They were divided into four groups.Control group:MNT?without copper group?and experimental group:MNT-1?0.5 g/L copper group?,MNT-2?1.0 g/L copper loading group?,MNT-3?1.5 g/L copper loading group?.After sand blasting the titanium plate was anodized twice at a voltage of 30V.Copper was deposited on the titanium dioxide sample by electrodeposition.Field emission electron microscopy?FESEM?and energy dispersive spectroscopy?EDS?were used to examine the surface morphology and elements of the specimens.Mouse osteoblasts?MC3T3-E1?purchased from the Shanghai Cell Bank of the Chinese Academy of Sciences were used as experimental cells.Applied materials and the method of cell co-cultivation was used to examine the effects of materials on cell proliferation.Early cell adhesion was detected using DAPI.The surface of the material was stained with a cytoskeleton to detect the state of cell elongation.The antibacterial properties of the cells were measured by AO/EB staining of Porphyromonas gingivalis?Pg?.Results:Etched pure titanium specimens were anodized twice after the sandblasted.the surface had different levels of pit-like structures and the formation of micro-nanotubes.From the elemental analysis of the energy spectrum,copper successfully loaded on the surface of the oxide film,and slightly increased with the concentration of the electrodeposition solution.CCK-8 experiments confirmed that the cell viability of MNT-1 group is gradually increased with time.The cell viability of MNT-1 group was higher than that of MNT group?P<0.05?compared with MNT group and MNT-1 group on the 7th day.There was no significant difference about cell viability between the MNT-2 group and the MNT-3 group in the first and third days?P>0.05?.The cell viability in the fifth and seventh days was significantly lower than that in the MNT group.The difference was statistically significant.?P<0.05?.The 0.5g/L Cu-loaded copper coating promoted cell proliferation to a certain extent.As time went by,the cytotoxicity appeared in the higher concentration of 1.0 and 1.5g/L copper.The appropriate copper concentration was selected.DAPI staining was found that the number of cell adhesion on the surface of each group of specimens is gradually increased with the prolongation of time.The number of cell adhesion in the MNT group and the MNT-1 group was more intensive,while the number of cells adhered in the MNT-2 group and the MNT-3 group was sparse.DAPI staining quantitative analysis shows that the adhesion tendency of MNT-1 and MNT groups is consistent,and there is a convergence trend of cell adhesion after 8 hours.The MNT-2 and MNT-3 groups may be released by high concentration of copper ions,so the increase of cell adhesion on time is not significant.Cytoskeletal staining was used to observe the morphology of the cells.MC3T3-E1 cells were even distributed on the surface of the MNT-1 specimen.The cytoskeletal morphology was complete and full.The amount of actin filaments in the cells was abundant.The concentration of 0.5g/L copper was tested.The pieces adhered,stretched,and grew well.The copper-loaded TiO₂ in each group showed obviously damage to the biofilm of Porphyromonas gingivalis.The destruction effect increased with the increase of the copper loading of electrodeposited copper.Conclusion:After sandblast etching,the electrodeposited 0.5g/L copper-bearing Cu composite coating cells have good proliferation,adhesion and stretching properties after two anodizations which reduces the probability of bacteria forming biofilm.The surface-loaded inorganic antibacterial copper composite coating has good biocompatibility and antibacterial activity.