转基因干细胞复合纳米羟基磷灰石胶原/聚乳酸修复骨缺损的实验研究

摘要

目的 研究以纳米羟基磷灰石胶原/聚乳酸(nHAC/PLA)材料为载体支架,复合用骨形态发生蛋白(BMP)-2修饰的骨髓间充质干细胞(BMSCs)构建的组织工程骨修复大鼠桡骨骨缺损的能力.方法 将48只成年的SD雄性大鼠随机分为4组,每组12只,制作成右侧桡骨为5 mm的骨缺损模型,各组分别按以下方法将材料植入骨缺损处进行修复.A组:nHAC/PLA材料+BMSCs[BMP-2和增强绿色荧光蛋白(eGFP)处理];B组:nHAC/PLA材料+BMSCs(无BMP-2和eGFP处理);C组:单纯nHAC/PLA材料;D组:空白对照组(只造骨缺损模型,不置入支架材料).术后6、12周用空气栓塞法各组分别处死4、8只大鼠并取右侧整段桡骨,行大体形态学、X线检查、组织学和生物力学检查.结果 X线观察结果:A组的骨痂形成量优于其他组,B组次之,C组稍逊于B组,空白对照组最少.组织学观察结果:A组的新生骨以及新生血管的形成等均优于其他各组,B组次之,C组稍逊于B组,空白对照组则最差.12周时4组生物力学测试结果显示:A组最大应力测试明显优于C组,B介于A组与C组之间,空白对照组最差.结论 nHAC/PLA是一种良好的载体支架材料,与经过BMP-2修饰的BMSCs复合后能显著提高骨生成的速度,在修复长骨节段性缺损方面具有潜在的临床价值.%Objective To determine the capacity of nano hydroxyapatite collageri/polylaclie acid (nHAC/PLA) as carrier scaffold in combination with bone mesenchymal stem cells (BMSGs) modified with bone morphogenic pro-leiri-2 (BMP-2) for repairing radial defects in rats. Methods Forty-eight male adult SD rats were randomly assigned into tour groups (12 per group) for preparation ot 5-centimeter bone defect models of the right radius. This was followed by implantation of materials for further repair. Group A was treated with r. HAG/PL A plus BMSGs modified with BMP-2 and enhanced greer. fluorescent protein (eGFP). Group B received implantation of nHAC/PLA plus BMSCs without pre-treatment of BMP-2 and eGFP. Group C were implanted with nHAC/PLA. While scaffold materials were not implanted in group D (blank control group). Four and eight rats were sentenced by producing air thrombosis at weeks 6 and 12, respectively, to extract right radius for morphologic. X-ray, histological and hiomechar.ies examination. Results In addition to the highest contents of osteotylus, group A yielded more advanced osteoger.esis and vas-culoger.esis and superior capacity for sustaining maximal stress at week 12, followed by group B, group C and control group, on the basis of X-ray, histological and hiomechar.ies examination, respectively. Conclusion As a preferable material for scaffolds, nll.AC/PLA could markedly promote osteoger.esis with BMP-2 modified BMSGs and may be clinically useful tor the treatment of segmented long bone detects.