| 1.Mechanism of the inhibition or promotion of different concentrations of enoxacin on osteoclasts and osteoblasts.ObjectiveTo discuss the inhibition or promotion of enoxacin on osteoclasts and osteoblasts while it has anti-infective effect at the same time.MethodsBased on the concentrations of enoxacin,the experiment was divided into four groups: group A: 0 ?mol/L,group B: 10 ?mol/L,group C: 50 ?mol/L,and group D: 100 ?mol/L.We took mouse's bone marrow cells and induced osteoclasts according to the methods described in previous literatures.After we cultured cells for a period of time,TRAP staining,cell proliferation assay,and mouse osteoclast gene PCR were performed to compare the effects on various concentrations of enoxacin on osteoclasts,respectively.According to the same method mentioned in the previous literatures,we took rat's bone marrow cells and induced osteoblasts.After a period of time of culturing,ALP staining,cell proliferation assay,and rat gene PCR were performed to compare the effects on various concentrations of enoxacin on osteoblasts,respectively.ResultsOur results of cell proliferation indicated that the concentration of enoxacin has no effect on cell proliferation,however,the results of TRAP staining and mouse osteoclast PCR showed that the increasing concentration of enoxacin inhibited the formation of osteoclasts.Moreover,ALP staining,alizarin red staining and rat osteogenic gene PCR results revealed that the elevated concentration of enoxacin promoted the differentiation of osteogenic.ConclusionDifferent concentrations of enoxacin inhibited the formation of osteoclasts,within a certain range,the higher the concentration of enoxacin,the more powerful the inhibitory effect of the formation of osteoclasts;Meantime,it promoted the differentiation of osteoblasts.The higher the concentration of enoxacin,the stronger the effect of promoting osteoblasts differentiation.2.Mechanism of preparation of titanium implants with nano-tubular surface structure,establishment of drug-loaded and sustained-release system and sustained-release performance.ObjectiveTo prepare the titanium implants with nano-tubular surface structure and to establish the drug-loaded and sustained-release system and the sustained-release performance in the meantime.MethodsWe prepared the titanium implants with nano-tubular surface structure by mean of anodizing means.Enoxacin was placed in the nanotube cavity through low temperature vacuum freeze-drying method,and the surface of the titanium implants was coated with type I collagen/hyaluronic acid composite membrane.Then we observed the surface structure of the titanium implants by scanning electron microscopy(SEM)and study the sustained-release performance.ResultsThe titanium implants with nano-tubular surface structure could be prepared with anodizing method.The diameter of the nanotube cavity will vary according to the change of voltage.Low temperature vacuum freeze-drying method could load enoxacin in the nanotube cavity and the coverage of the type I collagen/hyaluronic acid composite membrane in the surface can increase the sustained-release effect of enoxacin.ConclusionNano-scale titanium implants with drug-loaded and sustained-release system can be prepared by anodizing means and low temperature vacuum freeze-drying method as well as the coverage of the type I collagen/hyaluronic acid composite membrane in the surface meanwhile for further experimental research.3.Mechanism of the promoted effect of osteogenesis with the sustained-release system of titanium nanotube when jnjecting enoxacin into osteoporotic big rats.ObjectiveTo discuss the impact on osteogenesis effect of the drug-loaded and sustained-release system of titanium nanotube with enoxacin on osteoporotic big rats.MethodsWe prepared titanium implants with drug-loaded and sustained-release systems loaded enoxacin by using above methods and there is no internal research.Adult female SD big rats were taken to establish osteoporosis model,which was randomly divided into 4 groups: A.control group(Ti);B.pure nanotube group(Ti-NT);C.nanotube loaded enoxacin group(Ti-NT+EN);D.nanotube loaded enoxacin and type I collagen/hyaluronic acid composite membrane group(Ti-NT+EN+Col/HyA).Big rats in each group were implanted with their respective implants.After 4 weeks,the specimens are taken for micro-CT study.After 6 weeks,partial tissue sections were stained with H-E.ResultsThe micro-CT scan and HE staining of tissue section indicated that bone trabecular loose in the control group(Ti)and nanotube group(Ti-NT);what's more,the new bone trabecular had many structure and regular arrangement in the nanotube loaded enoxacin group(Ti-NT+EN)and nanotube loaded enoxacin and type I collagen/hyaluronic acid composite membrane group(Ti-NT+EN+Col/HyA).The parameter results revealed that the Ti-NT+EN+Col/HyA group was superior to the Ti-NT+EN group(P<0.05).ConclusionWith electrochemical method,the surface of the implant was modified thus forming a nano-scale lumen-like surface structure.Then the sustained-release system was formed by loading enoxacin and the coverage of type I collagen/hyaluronic acid composited membrane.This would promote osteogenesis of big rats with osteoporosis. |
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