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BACKGROUND: Both lentiviral vector and adenoviral vector are considered as good vectors for gene mediation, and their differences in transferring bone morphogenetic protein 2 (BMP-2) into rabbit bone marrow mesenchymal stem cells (BMSCs) are unclear. OBJECTIVE: To compare the duration, efficiency and the deviation of exogenous gene expression after rabbit BMSCs transfection using lentiviral vector and adenoviral vector which are used to mediate enhanced green fluorescent proteins (EGFP) and BMP-2. METHODS: Rabbit BMSCs at passage 5 were exposed to Ad-EGFP-BMP-2 (group A) or Lenti-EGFP-BMP-2 (group B) with multiplicity of infection of 100, as transfection groups. And in control group (group C), the same quality of culture medium was required equivalent to the groups A and B. The expression of EGFP was observed by inverted fluorescence microscope at various time intervals. And the expression of exogenous gene BMP 2 in cells was detected and analyzed by immunohistochemical staining at 72 hours after transfection as well as by western blot at 72 hours, 1, 3 weeks after transfection. RESULTS AND CONCLUSION: The intense green fluorescence emerged under the microscope at 24-48 hours after transfection in group A, which was stronger than group B, reached the peak at 72 hours, and then decreased at 1 week until disappearance at 3 weeks. No EGFP expression was detected in group C. High expression of BMP-2 was found in group A but was dramatically downregulated after 1 week. Group B showed the high expression of EGFP/BMP-2 persisted for a longer period after transfected that even lasted for 3 weeks. Overall, the lentiviral vector and adenoviral vector can efficiently transfect rabbit BMSCs and stably express the target gene of EGFP/BMP-2. Under the same MOI, compared to the adenoviral vector, transfection of lentiviral vector to rabbit BMSCs is more effectively and expression of EGFP/BMP-2 can be persistent in a longer term.
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Objective To observe the biocompatibility of rabbit bone marrow mesenchymal stem cells (BMSCs)combined with allogeneic decalcified bone matrix(DBM)after transfecting adenoviral recombinant human bone morphogenetic protein-2(Ad-rhBMP-2).Methods The rabbit allogeneic DBM material was prepared according to the Ursit method.After transfecting Ad-BMP-2 on rabbit bone marrow mesenchymal stem cells,the immunohistochemical was used to detect the expression of BMP-2 in the transfected cells;after 48 h of transfection,the cells were planted on the allograft DBM,then the scanning electron microscopy was used to observe the cell growth and adhesion condition on material,and the proliferation condition of BMSCs was detected by MTT. Results After 48 h of adenoviral transfection,BMSCs could express BMP-2 successfully.The scanning electron microscopy showed that the cells after transfection adhered well and massively proliferated on DBM material.The MTT assay showed that the prolifer-ation condition of the cells after transfection planted on DBM was normal,which showed no statistically significant difference when compared with the control group (P >0.05).Conclusion The Ad-BMP-2 transfection on BMSCs is well biocompatible to allogene-ic DBM.
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Objective To evaluate the effect of human bone morphogenetic protein 2 (hBMP-2)/Bone Mesenchymal Stem Cells (BMSCs)/demineralized bone matrix(DBM) on repairing rabbits’femoral head after necrosis and to explore the new treatments for femoral head necrosis. Methods Femoral head necrosis models was established by clinical core decom?pression combined with liquid nitrogen frozen. Then, animals were randomly devided into 4 groups (n=12 per group):Group A were not implanted anything as control group, Group B were implanted with DBM. Group C were implanted with hBMP-2/DBM. Group D were implanted with hBMP-2/BMSCs/DBM. Four rabbits from each group were sacrificed at 4,8 and 12 weeks after surgery to evaluate the the repairing effect of Osteonecrosis of the femoral head (ONFH) through X-ray examina?tion, observation of the specimen and HE staining. Results X-ray revealed defect of femoral head in Group A without clear bone formation. There is a little fibrous hyperplasia and no obvious osteogenic response. By contrast, the femoral head defect areas became fuzzy in group B, group C and group D with new bone trabeculars. And the regenerate phenomenons of group D were significantly better than that of group B and group C of the same time point. As to the Lane-Sandhu X Ray scores, it is lower in group A than that in group B;It is lower in group C than that in group D(P<0.05). There is no statistical difference between Group B and Group C. General observation of the specimen revealed that the femoral head of group A collapsed with drilling holes. The femoral heads of group B and group C showed no collapse but the drilling holes existed. Femoral head in group D was not collapsed and the drilling holes disappeared. HE staining showed that bone trabeculars became ne?crotic and fragmented in Group A with a lot of air trapped cells. There were newborn immature bone trabeculars and osteo? blasts in group B and group C. Group D were of large number of bone cells, fat cells, and newborn mature bone trabeculars. The ratio of empty lacuna is higher in Group A than that in Group B;it is higher in Group C than that in Group D(P<0.05). Conclusion hBMP-2/BMSCs/DBM can induce BMSCs differentiation into osteoblasts after being implanted. It has good re?pairing effect on ONFH with good application prospect.