| Objective:To do a research for making the bovine demineralized bone putty, and use the putty to repair the rabbit radius segmental defects to evaluate its osteoinduction. Methods:Made the particles of complete decalcification bovine cancellous bone and extracted and purified the bovine bone morphogenetic protein (BMP) by chemical methods, through the vacuum freeze dryers to recombine cancellous bone and BMP to make the reconstituted bone xenograft (RBX) meal, then, added carboxymethylcellulose (CMC), by a certain percentage, as a handling agent and packaged aseptic. Bone putty can be made to add appropriate saline or blood when used. Then, the putty was observed by aperture and BMP complex with the scanning electron microscopy(SEM), and general observation.27Japnese rabbits, male and female open, set up1.5cm defective model of the left side radial, and divided into3groups randomly. Group A with nothing, group B with reconstituted bone xenograft (RBX, jinshizhiguling), and group C repaired with the recombined putty. The new bone formation of each group were compared with others by observations, X-ray, histopathological analysis and transforming growth factor β1(TGF-β1) expression in the new bone to evaluate the osteoinduction of the bone putty and bone defect repairing capacity,wich in the period of2,4,8weeks after operation. At the same time, analysis the image of the percentage of new bone tissue area and area percentage of residual material, all data were analyzed statistically.Results:The bonvine demineralized bone putty could be shapen easily according to the size of defect in operation. It were completely healed to all the rabbits wounds after two weeks. After2weeks:defects of group A didn’t appear new bone; new bone of group B did not obvious, some RBX degradated; group C showed that a small amount of new bone had formed and a small amount of bone putty had remained. After4weeks:group A at both ends of bone defect had no obvious new bone; group B there was new bone formation and the material was not degradable; new bone of group C was rich and connected with the host bone, the osteopontin was formed, but new bone was lower density. After8weeks:two ends of bone defect density in group A was increased, hardening; the two ends of defect in group B was connecting, but the implanted material has not been completely absorbed and degradation, showing high-density image; new bone of group C appeared more closely and medullary cavity had connected. It could be seen simultaneously the expression of TGF-β1in new bone tissue within2weeks showed strong positive expression, positive at4weeks, weakly positive at8weeks. In addition, the new bone area and the area of residual implant material in different periods compared with each other, The osteogenic potential of the group C compared with group A and B had significant difference (P<0.01); the implant materials of group C degradated more quickly than group B, there was significant difference in statistics(P<0.01).Conclusion:Bovine demineralized putty combined BMP have a good bone effect repairing ability, biocompatibility, handling characteristic, and its degradation speed was simlar to the speed of new bone. It is a good filling implant material for treatment of bone defects. |
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