Reinforcing effect of calcium sulfate cement bovine bone morphogenetic protein on vertebral in the rabbit model of osteoporosis

OBJECTIVE@#To observe reinforcing effect of calcium sulfate cement (CSC) bovine bone morphogenetic protein (bBMP) on vertebral in the rabbit model of osteoporosis.@*METHODS@#A total of 48 New Zealand white rabbits were randomly divided into group I (blank control group), group II (CSC injection group), group III (CSC/bBMP injection group) and control group. White rabbit osteoporosis model was established rapidly by using castration method+methylprednisolone candidate. After modeling, groups II, III were given corresponding vertebral body injection material, and 4 animals were sacrificed respectively at 24 h, 6 weeks, 12 weeks after vertebral plasty. Tissue pathological status, vertebral mineral density and vertebral body bone mechanical strength were observed.@*RESULTS@#Vertebral body structure form was normal in the groups II and III. Trabecular bone coarsens, connection and repair were observed in micro fracture and bone defects, bone trabecular connectivity was superior to group I significantly; vertebral body compression strength in the group I was on the decline, vertebral compression strength in the groups II and III was on the rise, the largest vertebra. Postoperative BMC and BMD in groups II and III were increased, and significantly higher than group I after 6 weeks (P<0.05), BMC and BMD in group III after 12 weeks were higher than the other three groups.@*CONCLUSION@#Compound bBMP CSC has good bone induction. It can improve the three-dimensional construction effect for osteoporosis vertebral trabecula, and can significantly improve the vertebral strength, as a vertebral packing material with good application prospect.

Developmental and Experimental Study of Bionic Bone MHA-bBMP / 中国康复理论与实践

@#ObjectiveTo investigate the effort of MHA-bBMP implantation combined with limited contacted titanium net duct fixation on femoral shaft bone defect of rabbit.Methods48 rabbits were divided into the experimental group (treated with bionic bone MHA-bBMP plus titanium net duck) and control group (treated with iliac autograft plus titanium net duct) with 24 animals in each group. The rabbit femoral shaft bone defect model was established by cutting 10 mm bone fragment off. After operation, bionic bone MHA-bBMP/iliac autograft was implanted into bone defect area and fixed with limited contacted titanium net duck. The general condition, serum alkaline phosphatase, X-ray, histopathologic examination and electron microscope were performed.ResultsThe fixation stability of titanium net duck in two groups was good. The bone defect of two groups was repaired. The results of phosphatase, X-ray, histopathologic examination and electron microscope of two groups were not significantly different.ConclusionBionic bone MHA-bBMP is a high bioactivity substitute, and can obtain therapeutic effect equal to iliac autograft when repairing rabbit's femoral shaft defect.

Evaluation of the Interfaces Between Implants And Regenerated Bone Using Bone Morphogenetic Protein and Demineralized Freeze-dried Bone

Various methods and graft materials have been used to fill in the defect adjacent to the implants and considered as clinically acceptable. But it is not clear whether the regenerated bone increases the implant-bone contact and supports the implant. The purpose of this study is to evaluate regenerated bone surrounding implants using bone morphogenetic protein(BMP) and demineralized freeze-dried bone(DFDB), and the interfaces between implants and regenerated bone. bBMP was extracted and partially purified from the bovine bone matrix using heparine chromatography. Demineralized freeze-dried bone was made from the dog. Inactive insoluble collagenous bone matrix(IBM) of dog was used as carrier of bBMP. Interfaces of titanium coated epoxy resin implants were processed for demineralized section for transmission electron microscopy(TEM) and those of screw type implants were for nondemineralized section for light and fluoromicroscopic examination. Implants were inserted in the inferior border of mandible of adult dogs and artificial bony defects (3x3x4mm) were made at the mesial and distal side of implants. Defects were filled with BMP(BMP group) and DFDB(DFDB group). For the fluoromicroscopic examination, the fluorescent dyes (oxytetracycline, calcein green, alizarin red) were injected 2, 4, 6, 8, 12 weeks after implantation. The experimental animals were sacrificed at the 6th and the 12th week and their mandible were extirpated and processed for examination with light microscopy, fluoromicroscopy and TEM. The obtained results were as follows : 1. By the light microscopic findings, the defects were filled with woven bone at the 6th week and compact bone at the 12th week, and the osseointegrations were seen in both groups. There was no histological difference between them. 2. On the basis of the histomorphometric analysis, BMP group (6th week: 40.25%, 12th week: 56.04%) had higher bony contact ratio than DFDB group (38.37%, 42.63%). There was significant difference between two groups at the 12th week (P<0.05). 3. The amount of bone formation in BMP group was more prominent than in DFDB group. Significant difference was noted among two groups at the 6th and the 8th week (P<0.05). 4. By the transmission electron microscopic findings, 0.4-2micrometer soft tissue layer was found in adjacent to the interfaces and over the collagen fibrils of bone at the 6th week. However, about 100nm amorphous layer was noted at the interface or collagen fibrils directly extended to the titanium surface at the 12th week. There was no significant difference between two groups. 5. These results suggest that BMP and DFDB can be used as good graft materials in the regeneration of bone adjacent to implant, and BMP is more valuable as a bone inducer than DFDB.