Treatment of bone defect with osteoblasts transfected by transforming growth factor-beta 1 gene in combination with biomimetic biodegradable polymer scaffolds / 中国组织工程研究

ABSTRACT

BACKGROUND: How to deal with bone defect is a big problem to surgeons. In recent years, the development in the technology of molecular biology and tissue engineering provides broad prospect for the clinical treatment of bone defect, which is one of the important study directions in department of orthopedics. The transforming growth factor-beta 1(TGF-β1),one of the important factors in bone formation, plays an important role in bone metabolism and recovery.OBJECTIVE: To observe the therapeutic effects of bone defects with osteoblasts transfected . By TGF-β1 combining with biomimetic biodegradable polymer scaffolds.DESIGN: Randomized controlled trial.SETTING: Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology.MATERIALS Siderophilin, trypsin, 3H-proline and sirius red, etc.MATERIALS The experiment was completed in Union Hospital, Tongji Medical College, Huazhong University of Science and Technology from March to August in 2003. Twenty healthy adult Sprague-Dawley(SD) rats of SPF grade, weighing 200-250 g, were provided by the Experimental Animal Center of Tongji Medical College.METHODS: The osteoblasts transfected by TGF-β1 gene, combining with poly-DL-lactic acid scaffolds modified with poly-L-lysine, were transplanted into rat tibia defect. Radiographs and histological analysis were performed to evaluate the repair effects.MAIN OUTCOME MEASURES: The X-ray evaluation and histology observation were performed at the 4th and 8th weeks after the operation.RESULTS: Totally 20 SD rats were included in result analysis without one rat missing. ①In the experiment group, X-ray image indicated callus formation, while histology observation showed osteoid tissue and new bone formation, and osteoblasts attached to the surface of the materials after 4 weeks. Eight weeks later, the defect was essentially repaired, and the bone density of new bone was similar to that of the autogenous bone. ②In the control group, there was no formation of callus and osteoid tissue, and few osteoblasts attached to the surface of the materials, and a lot of lymphocytes infiltrated and blood capillary grew in the lacune of materials after 4 weeks. Eight weeks later, the imbedded materials were substituted mostly by fibrous tissue.CONCLUSION: The ideal repair effect of bone defect can be obtained through the combination of molecular biology with tissue engineering.