The experimental study for creating an artificial nerve conduit with Schwann cells

目的：用雪旺细胞或骨髓细胞作为可吸收人工管，对大鼠坐骨神经缺损进行桥接实验研究，并探讨其有效性。方法：实验一：采用大孔胶原蛋白管桥接15mm长的神经缺损（n=12）。实验二：我们使用聚乳酸管桥接15mm长的神经缺损。分为聚乳酸组（n=6）、层粘连蛋白包被聚乳酸组（n=3）、层粘连蛋白包被聚乳酸骨髓单核细胞组（n=3）。实验三：我们使用聚乳酸管桥接15mm长的神经缺损。制备PLA填充胶原蛋白凝胶组（n=3）、PLA填充胶原蛋白凝胶组（n=3）、PLA填充胶原蛋白凝胶组（n=3）和PLA填充胶原蛋白凝胶组（n=3）。结果：实验一：术后8周，所有病例在镜下均保持导管的连续性，但镜下有3例在导管中心可见神经再生。多孔结构的消失似乎阻止了轴突的再生。实验二：术后8周聚乳酸组和层粘连蛋白包被聚乳酸组均未见中枢神经再生。骨髓单核细胞组2例中心部见神经再生，1例远端见神经再生。实验三：术后8周聚乳酸组和培养骨髓基质细胞组均未见中心神经再生。培养的雪旺细胞组中央可见神经再生。结论：我们发明的聚乳酸管在一定时期内保持了管状结构，是一种有用的神经导管。由于大量培养的雪旺细胞需要牺牲更大的周围神经，因此培养的雪旺细胞的使用是困难的。另外，有人认为骨髓单核细胞促进神经再生。

Purpose : We performed experimental studies of bridging a nerve gap of a rat sciatic nerve by absorbable artificial tubes with Schwann cells or bone marrow cells and investigated the usefulness of them.Methods : Experimet I : We used a macroporous collagen tube and bridged a 15mm long nerve defect (n=12). Experiment II : We used a PLA tube and bridged a 15mm long nerve defect. PLA group (n=6), laminin-coated PLA group (n=3), laminin-coated PLA with bone marrow monocyte cells group(n=3) were made. Experiment III : We used a PLA tube and bridged a 15mm long nerve defect. PLA packed with collagen gel group (n=3), PLA packed with collagen gel with cultured Schwann cells group (n=3), PLA packed with collagen gel with cultured bone marrow stromal cells group (n=3) were made.Results : Experimet I : Eight weeks postoperatively the continuity of a tube was held in all cases macroscopically, but microscopically nerve regeneration was seen at the center of the tube in three cases. Disappearance of porous architecture seemed to prevent axons from regenerating. Experiment II : Eight weeks postoperatively nerve regeneration was not seen at the center in PLA group and laminin-coated PLA group. Nerve regeneration was seen at the center in two cases and at the distal part in a case of of bone marrow monocyte cells group. Experiment III : Eight weeks postoperatively nerve regeneration was not seen at the center in PLA group and cultured bone marrow stromal cell group. Nerve regeneration was seen at the center in a case of cultured Schwann cells group.Conclusion : The PLA tube that we invented was considered to be useful as a nerve conduit because of keeping tubal architecture at some periods. As large amount of cultured Schwann cells needs the sacrifice of a larger peripheral nerve, the use of cultured Schwann cells is difficult. Alternatively, it was suggested that bone marrow monocyte cells facilitate nerve regeneration.