| Due to the high occurrence fractures,bone infection,and bone tumors,the resulting bone defects have always been a difficult challenge in clinical practice.Autologous bone grafting is the accepted gold standard,but artificial bone substitute materials are also emerging this year.At present,the most widely used ones are calcium phosphate,calcium sulfate and some composite materials with them as scaffolds,and among them,calcium sulfate has the advantages of osteoconductivity,suitable degradation time,and non-heating combined with drugs,so its application is high.In calcium phosphate.At present,most of the calcium sulfate used in clinical practice is implanted alone or mixed with sensitive antibiotics.There are few studies and applications for the treatment of bone defects with vascular growth-related factors.It is well known that rapid vascularization of the graft facilitates its survival and repair of defects Therefore,improving the ability of artificial bone vascularization will greatly improve its bone repair performance.In the past,the research on the modification of calcium sulfate and the enhancement of bone repair ability were mostly combined with organic materials such as PLGA and polypropylene to form a new composite material.By searching the literature,there was no report on the implantation of calcium sulfate artificial bone combined with pro-angiogenic growth factor.In this study,a 3.0mm Kirschner wire was used to the bone defect model in the distal femur of rats.Then,calcium sulfate alone and calcium sulfate loaded with different doses of VEGF were implanted at various times.Observe and analyze changes in bone regeneration and angiogenesis.ObjectivesDifferent changes of bone regeneration and angiogenesis were observed after bone defect was not implanted,calcium sulfate alone was implanted,calcium sulfate was implanted at different doses of VEGF.Method1.Experimental animals and their grouping,establishment of bone defect model,material implantation surgery.A total of 75 adult male rats were divided into two treatment groups:2w,4w,6w,and bone defects were made in the distal femur of rats by 3.0mm Kirschner wire.Each group of 25 rats was randomly divided into 5 different treatment groups.The distal part of the left femur was taken as a bone defect,and the incision was closed after the material was implanted according to different treatment methods after modeling.Regular feeding.2.Specimen processingX-ray films were taken regularly from each group of animals after surgery.At the time of treatment,conventional fixation of the left femur was taken,as well as preparation and angiography.3.Testing indicatorsX-ray examination:All rats were examined by X-ray(Gendex Dental System,Milan,Italy).Micro-CT examination:The femoral bone of the experimental angiography was scanned by the small animal Micro-CT(Skyscan1176,Bruker Micro-CT,Belgium)before and after decalcification(including the distal end 2mm area of the operation area).Computational analysis was performed using the accompanying ANT Software(Skyscan 1176)software.Histomorphometrnc examination:sections were stained with HE and immunofluorescence.An imaging system with imaging analysis function(Leica DFC450C)and an inverted fluorescence microscope(Leica DM IL LED FLUO)were used to observe HE stained sections and immunofluorescence stained section srespectively.ResultFrom the examination of histological examination,X-ray and Micro-CT,it can be seen that after the addition of VEGF,the calcium-forming ability of calcium sulfate is stronger,and the vascularization process is faster after implantation,which is beneficial to the repair of bone defects.Conclusion:Implantation of calcium sulfate group is more faster than bone regeneration and angiogenesis in the blank group,and calcium sulfate loaded with VEGF can significantly promote bone and blood vessel regeneration and enhance the bone repair ability of calcium sulfate. |
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