组织工程骨修复节段性骨缺损的实验研究

目的 探讨用多孔β-磷酸三钙生物陶瓷（β-tricalcium phosphate,β-TCP）与自体骨髓问充质干细胞（autologous bone marrow mesenchymal stem cells,MSC）构建组织工程骨修复节段性骨缺损的效果。方法 在羊左跖骨中段形成21mm长的骨缺损,实验组植入组织工程骨;对照组单纯植入β-TCP;空白组骨缺损不作处理。术后1、3、6个月分批处死动物,缺损区行放射学、组织学、生物力学和扫描电镜等检测。空白对照组6个月取材。结果 实验组,骨缺损部位新生类骨样组织、编织骨和板状骨出现的时间都较对照组早,并且不经软骨介导即能直接成骨,而对照组以“爬行替代”方式修复骨缺损。放射学和生物力学检测显示术后6个月实验组骨缺损几乎完全修复,对照组部分修复,而空白组未愈合。结论 组织工程骨能加速骨缺损愈合的速度,其修复过程可超越“爬行替代”阶段;组织工程骨是治疗节段性骨缺损的一种较好选择方式。

The study of tissue-engineering bone for repair of segmental bone defects

OBJECTIVE: To investigate the effect of tissue-engineering bone on repair of segmental bone defects. METHODS: Segmental bone defect of 21mm was created at sheep left metatarsus, which was then implanted with tissue-engineering bone (the experimental group) and pure porous beta-TCP (the control group) respectively. The bone defect in the blank group was left without treatment. After the sheep were sacrificed at the 1st, 3rd, or 6th month postoperatively, the samples were taken and examined by radiological, histological and biomechanical methods as well as scanning electron microscopy. The sheep in the blank group were sacrificed at the 6th month postoperatively. RESULTS: The osteoid tissue, woven bone and lamellar bone in the defect of the experimental group occurred earlier than in the control group. The new bone formed directly without through a cartilaginous intermediate in the experimental group, while the defect was repaired in a "creep substitution" way in the control group. At the 6th month, radiological and biomechanical tests revealed nearly complete repair of the bone defect of the experimental group, partial repair in the control group and non-healing in the blank group. CONCLUSIONS: Tissue-engineering bone can repair bone defect, accelerating healing and without "creep substitution", which is a good option in repair of critical segmental bone defects. This study set up a basis for clinical applications in the future.