Study On The Revascularization Of New Non-cytotype Bone Tissue Engineering In Vivo

Objective:To study the revascularization and osteogenesis of bone masses taken from the rabbits undergone posterolateral lumbar spinal fusion with the new non-cytotype tissue engineering bone, which combined recombinant human bone morphogenetic protein-2(rh-BMP-2) with allograftat different time of the postoperation by positron emission tomography-computerized tomography(PET-CT) and flow cytometry. Methods:Forty-five adult New Zealand white rabbits were randomly divided into three groups:rhBMP-2/allograft composite group, autograft group and; allograft group, each group including 15 rabbits. Each rabbit was underwent L4, L5 intertransverse process fusion respectively. For the graft area, each group has been imaged by PET-CT and counted the number of vascular endothelial cell by flow cytometry at 2W,4W and 6W of the postoperation, in order to analysis SUV and the number of the proliferation of endothelial cells. Results:PET-CT shows that the SUV of autograft and composite group was superior to allograft group at 2W,4W,6W, P<0.05. The SUV of composite group was superior to autograft group at 4W,6W, P<0.05. For autograft and composite group, the SUV of 4W,6W was superior to the SUV of 2W, P<0.05, but the SUV had no significant differences between 4W and 6W, P＞0.05. Although the mean of SUV in allograft group was the highest at 4W, there were no significant differences at the three time, P>0.05. Flow cytometry shows that number of the proliferation of endothelial cells had statistically significant in different group at 2W,4W and 6W. The number of the proliferation of endothelial cells of composite group was superior to allograft group, P<0.05. The number of the proliferation of endothelial cells of composite group was superior to autograft group at 4W,6W, P<0.05. The number of the proliferation of endothelial cells had no statistically significant between composite group and autograft group at 2W,P>0.05. Conclusion:PET-CT and flow cytometry show that the rhBMP-2/allograft composite not only can promote bone formation but also can improve the blood supply in the posterolateral lumbar spinal fusion, so it might be the substituted material of autograft.