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

目的：我们进行了实验研究桥接神经间隙的大鼠坐骨神经可吸收的人工管与雪旺细胞或骨髓细胞，并探讨usefulness of thems.Methods：实验一：我们使用了大孔胶原蛋白管和桥接15 mm长的神经缺损（n=12）。实验二：用聚乳酸管桥接15mm长的神经缺损。实验分为PLA组（n=6）、Laminin包被PLA组（n=3）、Laminin包被PLA+骨髓单个核细胞组（n=3）。实验三：用聚乳酸管桥接15mm长的神经缺损。结果：实验一：术后8周，肉眼观察，所有病例均能保持导管的连续性，但显微镜下3例导管中心有神经再生。多孔结构的消失似乎阻止了轴突的再生。实验二：术后8周，PLA组和层粘连蛋白包被PLA组中央未见神经再生。骨髓单核细胞组2例神经再生位于中央，1例神经再生位于远端。实验三：术后8周，PLA组和培养骨髓基质细胞组中央未见神经再生。结论：我们研制的PLA管在一定时期内保持了原有的神经管结构，可作为神经导管使用。由于大量培养的雪旺细胞需要牺牲较大的外周神经，因此培养的雪旺细胞的使用是困难的。或者，有人建议，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.