生长因子缓释系统复合纳米支架材料修复犬下颌骨缺损*★

摘要

BACKGROUND: Scaffold materials are combined with cytokines to construct tissue-engineered bone, which cannot be limited by vascularization and cel culture. This reconstruction mode is able to induce a large-scale practical tissue-engineered bone. OBJECTIVE: To observe the ability of chitosan microsphere/nano-hydroxyapatite/poly(lactic-co-glycolic acid) scaffold with slow-released growth factors to repair critical mandibular defects in a dog. METHODS: Animal models of bilateral critical mandibular bone defects were established in 12 hybrid dogs. One side was implanted a chitosan microsphere/nano-hydroxyapatite/poly(lactic-co-glycolic acid) scaffold with bone morphogenetic protein 2, transforming growth factor-β1 and vascular endothelial growth factor 165 (experimental group); and the other side was implanted a chitosan microsphere/nano-hydroxyapatite/poly(lactic-co-glycolic acid). Manbidular specimens were harvested at postoperative weeks 4, 8 and 12 to carry out X-ray, histological and immunohistochemical examinations. RESULTS AND CONCLUSION: After surgery, the X-ray gray value and osteocalcin integral absorbance value in the experimental group were higher than those in the control group at different time points (P < 0.05), showing that the osteogenic ability of the compound growth factor scaffold is superior to the scaffold without growth factor in the repair of bone defects. Histological observation results showed that the ossification time and effect in the experimental group were better than those in the control group at different time point after surgery, indicating that the chitosan microsphere/nano-hydroxyapatite/poly(lactic-co-glycolic acid) scaffold with bone morphogenetic protein 2, transforming growth factor-β1 and vascular endothelial growth factor 165 can be faster and more effective to promote bone defect repair.%　　背景：支架材料联合细胞因子构建组织工程骨不受血管化和细胞培养因素的限制，这种构建模式可能诱导出较大体积的实用型组织工程骨。目的：观察壳聚糖纳米微球/纳米羟基磷灰石/聚乳酸-羟基乙酸复合生长因子缓释支架修复犬下颌骨临界骨缺损的能力。方法：取杂种犬12条，制作双侧下颌骨临界骨缺损模型，一侧植入复合生长因子骨形态发生蛋白2、转化生长因子β1及血管内皮生长因子165的壳聚糖纳米微球/纳米羟基磷灰石/聚乳酸-羟基乙酸缓释支架(实验组)，另一侧植入壳聚糖纳米微球/纳米羟基磷灰石/聚乳酸-羟基乙酸缓释支架(对照组)，术后4，8，12周取下颌骨标本行X 射线、组织学及免疫组织化学检查。结果与结论：实验组术后不同时间点X射线灰度值及骨钙素积分吸光度值均高于对照组(P <0.05)，表明复合生长因子的支架材料修复骨缺损的成骨能力优于未复合生长因子的支架材料。组织学观察结果显示，实验组术后不同时间点成骨时间及效果均优于对照组，表明复合生长因子骨形态发生蛋白2、转化生长因子β1及血管内皮生长因子165的壳聚糖纳米微球/纳米羟基磷灰石/聚乳酸-羟基乙酸缓释支架可更快更有效地促进骨缺损修复。