组织工程化生物活性骨膜应用于兔腰椎横突间的融合

Application of tissue engineered bioactive periosteum in lumbar intertransverse process fusion in rabbits

背景:脊柱后路融合是在特殊解剖、特殊生物学作用下的骨性融合过程,影响因素很多,对融合材料的选择考虑因素亦很多。近年随着骨组织工程学的发展,种子细胞复合支架材料体外构建组织工程化骨膜有望解决这一临床难题。目的:评价体外构建组织工程化生物活性骨膜为骨移植替代物应用于兔腰椎横突间融合的效果。方法:体外构建组织工程化生物活性骨膜植入24只健康成年新西兰大白兔腰椎横突间,每只兔子取3个横突间隙(Left L4,5,6,Right L4,5,6)植入3种材料。复合支架组Right L4,5植入诱导后骨髓间充质干细胞复合猪小肠黏膜下层、单纯支架组Right L5,6植入无细胞支架即单纯小肠黏膜下层、自体髂骨组Left L5,6植入自体髂骨。术后12周处死动物进行大体标本、影像学、组织学观察。结果与结论:大体标本比较复合支架组、自体髂骨组差异无显著性意义,均与单纯支架组比较差异有显著性义,影像学观察复合支架组、自体髂骨组上下横突间可见明显有骨小梁通过,单纯支架组未见骨密度影。复合支架组Ⅰ型胶原、骨钙素免疫组织化学染色强阳性,与自体髂骨组之间差异有显著性意义,单纯支架组未见阳性表达。实验提示利用猪小肠黏膜下层复合经诱导后向成骨细胞转化的骨髓间充质干细胞体外构建组织工程化生物活性骨膜是横突间融合骨移植的良好替代物。

BACKGROUND：Posterior spinal fusion is a process of bone fusion under special anatomical and biological effects,which affects by many factors.With the development of bone tissue engineering,in vitro constructed tissue engineered bioactive periosteum provides a new approach for solving this problem.OBJECTIVE：To evaluate the effect of in vitro constructed tissue engineered bioactive periosteum in treating lumbar intertransverse process fusion in rabbits.METHODS：In vitro constructed tissue engineered bioactive periosteum was implanted into lumbar intertransverse process of 24 healthy adult New Zealand rabbits.Three different materials were implanted into 3 transverse process gaps（Left L4,5,6,Right L4,5,6）of each animal.Namely,bone marrow mesenchymal stem cells（BMSCs）combined pig small intestine submucosa（SIS）were implanted into the right L4,5 of rabbits in the composite scaffold group;pure SIS was implanted into the right L5,6 of rabbits in the pure scaffold group;and autogeneic ilium was implanted into the left L5,6 of rabbits in the autogeneic ilium group.All rabbits were sacrificed at 12 weeks after operation to perform gross,imaging and histological observation.RESULTS AND CONCLUSION：The gross observation showed that there had no significant difference between the composite scaffold and autogeneic ilium groups,but the difference was significant compared with the pure scaffold group.Imaging observation showed that the trabeculae was formed in lumbar intertransverse of rabbits in the composite scaffold and autogeneic ilium groups,however,no bone density could be seen in the pure scaffold group.Type I collagen and osteocalcin were strong positive expressed in the composite scaffold group,which had obvious difference to the autogeneic ilium group.No positive expression could be found in the pure scaffold group.It suggested that tissue engineered bioactive periosteum constructed by BMSCs combined with SIS is a well alternative to autogenous graft materials for spinal fusion.