Construction Of Bismuth Trioxide Surface Of Titanium Alloy And Its Promotion Of Osteogenesis,Anti-Inflammatory,Antibacterial In Vitro

ObjectiveTo investigate the effect of bismuth trioxide surface on the biological behavior of mesenchymal stem cells and macrophages,and its antibacterial effect on Staphylococcus aureus and Escherichia coli.MethodsThe effect of Bi₂O₃ surface on runt-related transcription factor 2（RUNX-2）,osteopontin（OPN）,and osteocalcin（OCN）of rat mesenchymal stem cells（r BMSCs）is performed by reverse transcriptase-polymerase chain reaction（RT-PCR）.To study the effect of the surface layer of Bi₂O₃ on alkaline phosphatase（ALP）activity,ALP quantification experiments were performed.Mouse leukemia cells of monocyte macrophage（RAW246.7）were selected to study the effect of the surface layer of Bi₂O₃ on the expression of macrophage-associated inducible nitric-oxide synthase（i NOS）,interleukin-1（IL-1）,interleukin-10（IL-10）,and chemokine（C-C motif）ligand 22（CCL22）by RT-PCR.To study the antibacterial properties of the superficial layer of Bi₂O₃ through Staphylococcus aureus and Escherichia coli.ResultsThe results show that Bi₂O₃ layers of different thickness（thickness Ti-B3 >Ti-B2 > Ti-B1）have been successfully constructed on the surface of titanium alloy.The surface layer of bismuth oxide on the surface of titanium alloy has a similar surface morphology to titanium alloy.In vitro experiments,by Calcein-AM/PI and skeleton staining,it was found that the Bi₂O₃ surface of titanium alloy has good biocompatibility and low toxicity.RUNX-2 expression of Ti-B1,Ti-B2 and Ti-B3 expression was relatively low,while OPN expression was relatively high on the 7th day.OPN expressed by Ti-B3 and OCN expressed by Ti-B1,Ti-B2 and Ti-B3 were significantly overexpressed compared on the 14 th day,with Ti.In addition,Ti-B2 and Ti-B3 could significantly inhibit the relative expression of i NOS and IL-1.It was found that Bi₂O₃ surface of titanium alloy can inhibit the growth of Staphylococcus aureus and Escherichia coli.ConclusionsWe constructed the surface layer of Bi₂O₃ on the surface of titanium alloy by magnetron sputtering technology,and found that the original surface morphology of titanium alloy did not change significantly.Bismuth trioxide surface has good biocompatibility and low toxicity,and has good osteogenic induction ability in late bone maturation.The surface layer of Bi₂O₃ can inhibit M1 polarization of macrophages and reduce inflammatory response.In addition,the surface layer of Bi₂O₃ can also inhibit the growth of Staphylococcus aureus and Escherichia coli.In conclusion,the surface of titanium alloy Bi₂O₃ can enhance the bone integration ability and bacteriostatic ability of titanium alloy（Ti-B2 和 Ti-B3）,which has a good application prospect in orthopedic implants.