人骨形态发生蛋白2基因转染的骨髓基质细胞复合生物活性玻璃陶瓷

背景：目前已有将体外培养的骨髓基质细胞与支架复合修复骨缺损的临床报道。但是由于该类复合材料中缺乏骨生长因子作用，在原位的成骨作用并不十分理想。 目的：探讨携带人骨形态发生蛋白2基因的骨髓基质细胞复合生物活性玻璃陶瓷材料在修复兔颅骨缺损中的原位成骨作用。 设计、时间及地点：随机对照动物实验，于2005-02/2008-11在辽宁医学院解剖学实验室完成。 材料：生物活性玻璃陶瓷由中国科学院四川成都光电研究所提供，转人骨形态发生蛋白2和转pcDNA3载体的骨髓间充质干细胞由辽宁医学院解剖学教研室骨组织工程研究所保存。 方法：制备兔双侧颅骨骨缺损模型，将基因转染的骨髓基质细胞与生物活性玻璃陶瓷复合培养物植入骨缺损区，术后第4,8,12周对植骨区进行大体观察、X射线摄片、组织切片、组织化学检测。 主要观察指标：①复苏后的转染人骨形态发生蛋白2的骨髓基质细胞的生长特性。②从大体、X射线结果和组织学等方面观察复合材料在原位修复骨缺损的作用。 结果：转染的骨髓基质细胞在细胞形态及增殖特性方面与未转染的细胞无明显差异。扫描电镜显示基因转染的骨髓基质细胞在生物活性玻璃陶瓷表面呈星形紧密排列，长入生物活性玻璃陶瓷孔隙中。复合材料植入免颅骨缺损后，X射线观察术后第4周骨缺损外周骨质与复合材料之间大部分被高密度阴影充填，术后第12周骨缺损外周骨质与复合材料之间完全被高密度阴影充填；光镜观察术后第8周骨小梁大部分相连成片，术后第12周骨小梁粗大，骨髓再生。 结论：基因转染的骨髓基质细胞复合生物活性玻璃陶瓷材料基本符合骨组织工程学的要求，在骨缺损区原位具有良好的成骨作用。 关键词：骨髓基质细胞；基因转染；生物活性玻璃陶瓷；骨缺损

Human bone morphogenetic protein-2-transfected bone marrow stromal cells with bioactive glass ceramics for repairing skull defects

BACKGROUND: It has been reported that in vitro cultured bone marrow stromal cells (BMSCs) are replaced on stent in order to repair bone defect. However, osteogenesis in situ remains poorly ideal due to the absence of bone growth factors. OBJECTIVE: To investigate the osteogenic effect of BMSCs transfected by human bone morphogenetic protein-2 (hBMP-2) composited with bioactive glass ceramics (BGC) on repairing skull defects of rabbits. DESIGN, TIME AND SETTING: A randomized controlled animal study was performed at Department of Anatomy, Liaoning Medical University from February 2005 to November 2008. MATERIALS: BGC was provided by Chengdu Institute of Electro-Optical Science, Chinese Academy of Sciences; BMSCs transfecting hBMP-2 and pcDNA3 were provided by Department of Anatomy, Liaoning Medical University, Institute of Bone Tissue Engineering. METHODS: Bilateral skull defect rabbit models were established. The defects were filled with the transfected BMSCs and BGC compound. At 4, 8, and 12 weeks after operation, gross observation, X-ray examination, tissue sections, and histological test were performed in the defect regions. MAIN OUTCOME MEASURES: Growth characteristics of hBMP-2-transfected BMSCs; effect of the compound on repairing bone defect based on gross observation, X-ray examination, and histological test. RESULTS: There was no significant difference in morphology and proliferation between transfected BMSCs and non-transfected BMSCs. Scanning electron microscope indicated that the transfected BMSCs were star-like located on the surface of BGC and grew in the pore of BGC. After repairing skull defect using compound implant, X-ray examination demonstrated that space between peripheral sclerotin and compound implant was covered by high-density shadow after 4 weeks. Additionally, at the 12th week, the space between them was completely covered by high-density shadow. Optic microscope showed that a large majority of bone trabeculas were connected to each other at the 8th week, while the bone trabecula was thick and bone marrow regeneration was observed at the 12th week. CONCLUSION: The composition of hBMP-2-transfected BMSCs and BGC is satisfactory for bone tisse engineering and has a great effect on osteogenesis in defect region.