同种异体神经复合体修复兔周围神经缺损

背景：应用种植许旺细胞的去细胞同种异体神经复合体修复周围神经缺损，探索其对神经再生及功能恢复有更好的促进作用，并且免疫原性非常小。目的：用种植胎兔许旺细胞的去细胞同种异体神经复合体修复兔缺损的坐骨神经，观察移植神经周围免疫细胞的变化及功能恢复。 　方法：48只新西兰白兔随机分成实验组和对照组。两组动物均切除一段坐骨神经，造成2.0 cm长的缺损，实验组用种植胎兔许旺细胞的同种异体神经复合体修复坐骨神经；对照组仅用去细胞同种异体神经修复。移植后1，4，8周光镜观察移植段坐骨神经周围肌肉组织中免疫细胞的浸润情况，计数每个高倍视野免疫细胞的数量。移植后4，8，16周大体观察兔的足部溃疡形成及愈合情况，大体观察神经愈合情况；肌电图检查桥接段坐骨神经的传导速度。结果与结论：手术区局部均未出现明显的排斥反应，实验组足部溃疡愈合情况优于对照组。移植后1周移植段坐骨神经周围肌肉组织中有大量淋巴细胞及巨噬细胞浸润，实验组明显多于对照组(P < 0.05)；移植后4周，浸润的免疫细胞两组均较1周后明显减少，实验组减少更明显。移植后8周，浸润的免疫细胞更加减少，但两组间比较差异无显著性意义(P > 0.05)。移植后4周时，两组均未见明显的神经传导，8，16周神经传导速度实验组均优于对照组(P < 0.05)。提示，种植许旺细胞的去细胞同种异体神经复合体免疫原性非常小，对神经再生及功能恢复有更好的促进作用。

Allogeneic nerve complex for repair of peripheral nerve defects in rabbits

BACKGROUND: Acellular nerve graft with Schwann cells is used to repair peripheral nerve defects and have a better role in nerve regeneration and functional recovery with little immunogenicity.OBJECTIVE: To observe the changes of immune cells surrounding the nerve graft as well as functional recovery after acellular nerve graft with Schwann cells for repair of peripheral nerve defects. METHODS: Forty-eight adult healthy New-Zealand rabbits were randomly divided into 2 groups with 24 rabbits each group, based on different grafts. The bridging complex was composed of Schwann cells transplanted into the acellular nerve graft. The sciatic nerve of lower left limb was cut in order to emerge 2 cm nerve defect. Only acellular nerve graft was applied in the control group. The infiltrating of immune cells in the muscle tissue around allografts of the rabbit was observed after 1, 4 and 8 weeks, further, to count the amount of immune cells in each high power field. The ulcers on the feet of the rabbit and sciatic nerve regeneration were also observed at 4, 8 and 16 weeks after operation. The conducted velocity of the regenerated nerve was examined by the electrophysiological indices. RESULTS AND CONCLUSION: After operation, the immunological rejection was not found in the operating field. The experimental group was better than the control group in the healing of ulcers. There were lots of lympholeukocytes and macrophages in the muscle tissue around the transplanted sciatic nerve after 1 week. There were obviously more lympholeukocytes and macrophages in the experimental group than the control group (P < 0.05). They decreased after 4 weeks in two groups, they decreased more seriously in the experimental group, and obviously decreased after 8 weeks. There was significant difference between the experimental group and the control group after 1 week, but, there was not different after 4 weeks and 8 weeks. After 4 weeks, the conducted velocity of the regenerated nerve was not different between two groups. But at 8 and 16 weeks after operation, the experimental group had a better conducted velocity than the control group (P < 0.05). The acellular nerve allografts with Schwann cells could significantly promote nerve regeneration and functional recovery of injured sciatic nerve. Its immunogenicity is extraordinarily low.