Experimental Study Of The Bmp-2 Gene Modified Tissue-engineered Bone In Repairing The Bone Defect

【Objective】Bone defect cuased by truama, sarcoma, infection or congenital disease is one of the most common diseases in clinic. As many as millions patients in the world every year, and are difficult to heal. The current bone defects repairing materials include: autogenous bone, allogenic bone, artificial materials, composite materiel et al. All of these materials were not ideal. It is difficult to find ideal materials to repair bone defect susing one material. As a result of bone tissue engineering developing, the cells were co-cultured with a specific scaffold to construct the active composite materials, with the repair of bone defects has been achieved initial success. The aim of this study was to investigate the bone defectse repairing ability of the composite material, which with BMCSc transduced with hBMP-2 gene as its seeding cells and with Nano-HA as its scaffolds. Through a series of studies about its abilities of repairing bone defect, more new proofs will be provided for its application in treatment of bone defect in the future.【Methods】60 New Zealnad white rabbits about 2 months old were divided into A, B, C, D four groups randomly and numbered respectively. A group and B group were used to harvest bone marrow 2～3ml. The bone marrow was inspired from two lateral tibial tubercle of the rabbits. BMCSc were isolated from the bone marrow cells by density gradient centrifugation. When subcultured to 3 cells, the BMCSc of A group were transferred with hBMP-2 gene and cultured. The BMCSc of A group and B group were combined with Nano-HA and cultured for 5~7 days respectively. The animal models of bone defect: A group: The defect was repaired with BMCSc transduced with hBMP-2 gene combined with Nano-HA composite artificial bone; B group: The defect was repaired with BMCSc combined with Nano-HA artificial bone; C group: The defect was repaired with Nano-HA artificial bone; D group: The defect was unrepaired. Gross observation, histopathology study, X-ray, scanning electronic microscope and biomechanical analysis were performed in 4 weeks, 8 weeks and 12 weeks postoperatively. Comprehensive evaluation was carried out about the ability of bone reconstruction of BMCSc transduced with hBMP-2 gene combined with Nano-HA artificial bone.【Results】Adv-hBMP-2/BMCSc/Nano-HA composite artificial bone , BMCSc/Nano-HA composite artificial bone and Nano-HA artificial bone could stimulate new bone organization formation. But Adv-hBMP-2/BMCSc/Nano-HA composite artificial bone could stimulate more new bone organization formation and had better ability of repairing bone defect than that of BMCSc/Nano-HA composite artificial bone and Nano-HA artificial bone. The difference of reconstructive ability was statistically significant(P <0.05).【Conclusion】while Adv-hBMP-2/BMCSc as seed cells for bone tissue engineering involved in bone formation, synthesising and secreting BMP-2 which has a strong ability to promoted new bone formation, increasing capacity. Adv-hBMP-2/BMCSc/Nano-HA composite artificial bone defects has a good bone defect repaired capacity. It is expected to become an ideal material for repairing bone defects...