【作者】 李智；

【导师】 李祖兵；

【作者基本信息】 武汉大学 ， 口腔临床医学， 2004， 硕士

【摘要】 目的：观察以自体骨髓来源成骨细胞为种子细胞、异体脱钙骨为支架材料所构建的组织工程骨修复兔颌骨缺损的成骨能力及其效果。 方法：运用组织工程方法，将20只新西兰白兔自体骨髓来源成骨细胞于体外分离培养增殖后接种于异体脱钙骨，复合培养构建组织工程骨，随机植于一侧颌骨缺损区，另一侧骨缺损区植入单纯异体脱钙骨作为对照。术后分别于2、4、8、12周各处死5只动物取材，通过大体、影像学和组织学观察骨形成情况；对X线片进行计算机图像分析，计算并比较实验侧与对照侧骨缺损区的相对骨密度值。 结果：大体观可见对照侧新骨生长滞后于实验侧，12周时实验侧骨缺损区已完全由新骨所修复，而对照侧仍有小部分缺损区域未得到修复。影像学观察可见2周时实验侧与对照侧缺损区均为透光区，但实验侧密度稍高且缺损边缘有少量骨痂影。4周时实验侧缺损区的边缘及中央区域出现骨痂影像，8周时骨痂影像面积增大密度增高，至12周时缺损区已充满骨痂影。对照侧4周时缺损边缘区出现点状骨痂影，8周时逐渐汇合成片状，至12周时其密度增高，但远离植骨床的小部分区域仍为放射透光区。实验侧与对照侧缺损区各时间段的相对骨密度值具有显著的统计学差异(P＜0.05)。组织学观察可见实验侧2周时在新骨由植骨床长入移植骨的同时，移植骨的中央区域出现新生的骨组织，4周到8周阶段中央区的新生骨由编织骨向板层骨发展，至12周时新生骨与宿主骨相似。在对照侧成骨方式以“爬行替代”为主，在新骨形成的过程中可见新生骨与脱钙骨之间有大量的纤维组织长入。 结论：以自体骨髓来源成骨细胞为种子细胞、异体脱钙骨为支架材料所构建的组织工程骨具有骨生成、骨传导和骨诱导三重功能，其成骨能力及成骨质量显著强于单纯脱钙骨，是修复颌骨缺损的理想骨移植材料。更多还原

【Abstract】 Objective To investigate the osteogenetic capability and effect of tissue engineering bone in repairing mandible defects in rabbits, which was constructed by autogenous bone marrow derived osteoblasts and allogeneic demineralized bone.Methods The bone marrow derived osteoblasts of 20 New Zealand white rabbits were isolated, cultured and proliferated then seeded into the demineralized bone to construct tissue-engineering bone in vitro. The tissue engineering bone and demineralized bone were used respectively to repair the mandible defects in rabbits, and the latter was as the control. The bone formation was evaluated grossly, radiographically, histologically at 2, 4,8,12 weeks after transplantation. The relative bone density of defects in experimental and control sides were recorded and compared by using the computer analysis system on the x-ray image.Results Gross observation showed that the process of new bone growth in control defect was lagged when compared with experimental defect. At the 12th week the defect in experimental side was completely filled with new bone .In the 12-week control implant, partial defect was remained at the inferior margin. Radiographically, at the second week, both of experimental and control defect were radiolucent in the x-ray image, but the experimental defect had higher density and presented little bone callus image at the marginal region. At the 4th week, bone callus image presented in the marginal and center region of experimental defect, and the bone callus image increased greatly and had higher density at the 8th week. At the 12th week, the experimental defect was filled with bone callus image. In the control defect, spot-like bone callus image presented in the marginal region of defect at the 4th week. At the8th week, the region of bone callus image connected and increased. At the 12th week, higher density was observed, but a radiolucent region remained in the inferior part of defect far away from the host bone. There was statistically significant difference (P<0.05) between the relative density of the experimental defect and the control defect at the each time point within the four groups. Histologically, in the 2-week implant of experimental side, there was newly formation bone tissue in the center of implant with large amounts of bone trabecula from the host bone penetrated into the implant. In the 4-week implant and 8-week implant of experimental side, the new trabecular bone developed towards lamellar bone at center region. At the 12th week, the new bone was similar to host bone .In the control implant, the major osteogenetic pattern was "creeping substitute". There was a large amount of fibrous tissue growing between new bone and demineralized bone during new bone formation.Conclusion The tissue engineering bone constructed by autogenous bone marrow derived osteoblasts and allogeneic demineralized bone has the capability of osteogenesis, osteoconduction and osteoinduction with better osteogenetic effect and quality than demineralized bone implant, and is an ideal graft in repair of mandible defects.更多还原