快速成型聚乳酸-聚羟乙酸/磷酸三钙支架修复兔桡骨缺损

摘要 背景：理想的骨修复材料除必须具有生物相容性、可吸收性、利于血管化及迅速被新生组织替代的孔隙率，还需要有与骨组织相似三维结构。 目的：检验快速成型工艺制作的聚乳酸-聚羟乙酸/磷酸三钙支架复合骨形态发生蛋白修复兔桡骨缺损的效果。 方法：将乳酸乙醇酸共聚物溶于1,4-二氧六环中并混合粉末状磷酸三钙制备成液态的浆料，放入生物材料快速成形机TissFormTM制备出直径5 mm，长15 mm的圆柱形人工骨载体材料。按每个材料15 mg的标准，采用预湿、负压复合骨形态发生蛋白、冻干3步处理，制备出活性人工骨材料。健康新西兰大白兔20只，制备右前肢桡骨中上段15 mm骨缺损模型，实验组和对照组分别植入复合骨形态发生蛋白的活性人工骨和未复合骨形态发生蛋白的单纯支架。通过影像学、组织学、材料降解及骨密度评价修复兔桡骨缺损的效果。 结果与结论：12周时实验组骨缺损愈合，新生骨痂连接缺损断端并塑形，支架材料近于完全降解，各检测指标与对照组比较差异均有显著性意义，对照组骨缺损内未见新骨形成。结果表明复合骨形态发生蛋白的聚乳酸-聚羟乙酸/磷酸三钙支架可以很好的修复兔15 mm骨缺损，且降解速度与成骨速度匹配良好。 关键词：聚乳酸-聚羟乙酸；磷酸三钙；骨形成蛋白；桡骨缺损；骨组织工程 doi:10.3969/j.issn.1673-8225.2011.12.001

Poly(lactic-co-glycolic acid)/tricalcium phosphate scaffolds prepared by rapid prototyping technology for the repair of radial defects in rabbits

Abstract BACKGROUND: The ideal bone repair materials must be biocompatible and absorbable, have the porosity that is conducive to the vascularization and rapidly replaced by new tissue, as well as a three-dimensional structure similar to bone tissue. OBJECTIVE: To test the effect of poly(lactic-co-glycolic acid)/tricalcium phosphate (PLGA/TCP) scaffolds prepared by rapid prototyping technology loaded with bone morphogenetic protein in the repair of radial defect in rabbits. METHODS: The lactic acid/glycolic acid copolymer dissolved in 1,4-dioxane and mixed with calcium phosphate powder to prepare a liquid slurry, then placing into a biomaterial rapid prototyping machine TissFormTM, thus a cylindrical artificial bone carrier at the diameter of 5 mm and length of 15 mm was obtained. According to the standard of 15 mg in each material, active artificial bone materials were prepared by use of pre-wet, negative pressure of bone morphogenetic protein, freeze-drying. Twenty New Zealand rabbits were used to prepare a 15-mm radial defect, which was treated by the implantation of active artificial bone loaded with and without bone morphogenetic protein. Then results of imaging, histology, scaffolds degrade rates and bone mineral density was appraised to examine the repairing effects of the scaffolds. RESULTS AND CONCLUSION: At 12 weeks, all defects in the experimental group were radiographically repaired. New bony callus was observed to connect with the defect ends and then mould, the scaffold was nearly completely absorbed, and no significant differences were observed compared with control group. PLGA/TCP scaffolds prepared by rapid forming technology loaded with bone morphogenetic protein can effectively repair the 15-mm long bone defects in rabbits, its degradation rate well matched the bone formation rate.