Repair of nerve injury wrapped by encapsulated Schwann cells

为了促进面神经损伤再生，将纯化的雪旺细胞置于面神经损伤周围。根据Kim等人的描述，从SD大鼠背根神经节中获得成熟的雪旺细胞。每只SD大鼠（10周龄）暴露左侧面神经两外周支，用动脉瘤夹（Sugita 1号）夹持2分钟。以8mA恒电流刺激外露面神经近端和远端，记录诱发肌电图。两个刺激点之间的平均距离为25mm，分别在损伤前、损伤后和损伤后14天计算神经传导速度（NCV）。10份压伤部分覆盖含有雪旺细胞（1.0*10<@D18@>D1/ml）的胶原凝胶（0.3ml）（雪旺组），其余8份仅覆盖胶原凝胶（对照组）。电生理研究结束后，用4%多聚甲醛灌注大鼠神经，取出神经，石蜡包埋。用免疫细胞化学方法对5 mm厚切片进行HE和S-100蛋白染色。基线中译为47.6 (SY。+ -。[)6.8米/秒(平均(SY。+ -。[)SE)，损伤后显著降低（11.8(]SY.+- . [)2.7m/s）。伤后14 d，雪旺组NCV （30.3(]SY.+- . [)8.6m/s）显著大于对照组（11.2(]SY.+- . [)3.6m/s）。然而，免疫细胞化学未能显示在压伤神经周围移植的雪旺细胞。结果表明，在面神经周围移植雪旺细胞可促进面神经损伤后早期的神经再生。但其促进损伤神经修复的物质和机制尚不明确。

To facilitate the regeneration of crush-injured facial nerve, purified Schwann cells were placed around the crush-injured nerve.Mature Schwann cells were obtained from dorsal root ganglia of SD rats as described by Kim et al. The two peripheral branches of left facial nerve of each SD rat (10 weeks old) were exposed, and pinched with aneurysm clip (Sugita No.1) for 2 minutes. The evoked electromyograms were recorded by stimulating the proximal and distal portions of the exposed facial nerve (8mA constant current). The mean distance between the two stimulation points was 25mm, and nerve conduction velocity (NCV) was calculated before injury, just after injury, and 14 days after injury. Ten crush-injured portions were covered with collagen gel (0.3ml) containing Schwann cells (1.0*10<@D18@>D1/ml) (Schwann group), and the other 8 were covered with collagen gel only (control group). After electrophysiological studies, the rats were perfused with 4% paraformaldehyde, and the nerves were removed and embedded in paraffin. The 5 mum-thick slices were stained for HE and S-100 protein immunocytochemically. The baseline NCV was 47.6(]SY.+-。[)6.8m/s (mean(]SY.+-。[)SE), and it reduced remarkably just after injury (11.8(]SY.+-。[)2.7m/s). Fourteen days after injury, NCV of Schwann group (30.3(]SY.+-。[)8.6m/s) was significantly greater than that of control group (11.2(]SY.+-。[)3.6m/s). However, immunocytochemistry failed to reveal transplanted Schwann cells around crush-injured nerve.From these results, transplantation of Schwann cells around crush-injured facial nerve may facilitate the nerve regeneration in the early period after crush-injury. However, it was difficult to determine the substance and mechanism of facilitation of the repair of injured nerves.