多孔丝素蛋白支架修复兔下颌骨临界性骨缺损*★

摘要

背景：丝素蛋白具有良好的生物相容性和可降解性。目的：观察多孔丝素蛋白支架原位修复兔下颌骨临界性骨缺损效果。方法：建立兔双侧下颌骨临界性骨缺损模型，随机选取一侧缺损植入多孔丝素蛋白支架作为实验组，另一侧缺损不作处理作为对照组。结果与结论：①大体标本：术后12周，实验组骨缺损腔表面完全被新生骨覆盖，材料无脱出；对照组骨缺损腔内充满肉芽组织，骨不连。②X 射线骨密度测定：术后2，6，12周，两组骨密度均随着时间延长逐渐增高，组内不同时间点间差异有显著性意义(P <0.05)，且同期实验组高于对照组(P <0.05)。③组织病理切片苏木精-伊红染色：术后12周，实验组岛状新生骨及骨小梁明显增多，而且粗大而致密，材料内部明显疏松，部分区域塌陷；对照组宿主骨边缘可见散在分布的新生骨组织，但并无粗大骨小梁形成。④骨形态发生蛋白2免疫组织化学染色：术后2，6，12周，两组骨形态发生蛋白2阳性细胞数均随着时间延长逐渐增多，组内不同时间点间差异有显著性意义(P <0.05)，且同期实验组多于对照组(P <0.05)。表明多孔丝素蛋白支架用于原位组织工程修复骨缺损具有一定可行性。%BACKGROUND: Silk fibroin has excel ent biocompatibility and biodegradability. OBJECTIVE: To observe the effect of porous silk fibroin as a scaffold in repairing rabbit critical-size mandibular defects. METHODS: The rabbit models of critical-size mandibular defects were established. Randomly selected one side of mandibular defects was fil ed with porous silk fibroin scaffold as experimental group, and the other side served as control group without disposal. RESULTS AND CONCLUSION: (1) The gross specimen showed: After 12 weeks, in the experimental group, the surfaces of bone defect cavities were completely covered by new bone tissues, without materials prolapsed; in the blank control group, bone defect cavities were ful of granulation tissues. (2) X-ray bone density: As time after surgery on, both experimental group and control group had higher bone density, and 12 weeks > 6 weeks > 2 weeks (P <0.05), as wel as, the bone density in the experimental group was higher than that in the control group at the same period (P < 0.05). (3) Hematoxylin-eosin staining of histopatological slices: At 12 weeks after surgery, in the experimental group, new bone and islands of trabecular bone increased significantly, and became thicker and denser. Materials were obviously loose inside, some areas col apsed. In the control group, there were scattered new bone tissues in edges of host bone, and no coarse trabecular bone formed. (4) Bone morphogenetic protein-2 immunohistochemical staining: As time on, the number of bone morphogenetic protein-2 positive cells in new bone trabeculae increased to varied degrees after surgery in both experimental group and control group, and the difference within group was statistical y significant (P < 0.05); at each time, the number of bone morphogenetic protein-2-positive cells in the experimental group was higher than that in the control group (P < 0.05). These findings indicate that the porous silk fibroin scaffold has certain feasibility for in situ bone tissue engineering to repair bone defects.