Experimental Research Of Different Forms Of AAA Bone Combined With Vascular Endothelial Growth Factor For The Repair Of Bone Defects

Background:AAA bone is a kind of allogeneic bone of low antigen with comprehensive chemical(degreasing, deproteinization, decalcification) and freezing drying treatment. It preservesbone inducing factor, such as, bone morphogenetic protein. So, it can behooveosteanagenesis and bone defect reconstruction. Vascular endothelial growth factor (VEGF) isan inducing factor that could promote the proliferation and differentiation of vascularendothelial cells and the formation of blood vessels, and finally promote angiogenesis withsufficiency. VEGF plays a crucial role in the reconstruction, by chemotatic effects onosteoblasts and osteoclasts, and by promoting osteoblast proliferation and differentiation. Insuch, it exerts a great advantage in bone regenerationObjective:To investigate the effect of different forms of AAA bone combined with vascularendothelial growth factor（VEGF）on bone reconstruction.Materials and Methods:First, through the decalcified method, we finished the preparation of AAA bone anddivided it in two forms, particle and bulk. The AAA bone was mixed with300ng of VEGFrespectively in the ratio of1∶1.8, and were then prepared into AAA/VEGF bone. Twentyhealthy rats whose radiuses were cut off0.5cm were divided into five groups. Groups inwhich bone defects of rats were repaired with granular AAA, granular AAA/VEGF,massive AAA, massive AAA/VEGF bones were the experimental groups. The osteogenesisof AAA bone implanted into the defect area were evaluated by histological and CBCTanalysis at4weeks postoperatively.Result:No high dense region was detected in the control group through radiographicalexamination, whereas there were high dense image of different sizes in the experimentalgroup, among which the massive AAA/VEG bone and massive AAA bone possessed the largest bone volume. The histological results showed new bone regeneration in theexperimental group, better osteogenesis of granular AAA bone than that of massive AAAbone, and more bone volume formation by granular AAA/VEGF bone than that by granularAAA bone, and more bone volume formation by massive AAA/VEGF bone than that bymassive AAA bone in solitude. No osteoblast could be observed in the control group.Conclusion:1. AAA bone, the allogenic bone to which special treatment has been applied, has thepotential to be a bone graft material for bone restruction.2. The osteogenesis of granular allogenic bone is better than that of massive allogenicbone.3. Allogenic bone together with VEGF has a better new bone formation in the bonedefect than allogenic bone does in solitude.