Repair of nerve injury wrapped by encapsulated Schwann cells

为了促进挤压损伤的面神经再生，将纯化的雪旺细胞放置在挤压损伤的神经周围。按照Kim等人的描述，从SD大鼠的背根节获得模拟的雪旺细胞。暴露10周龄SD大鼠左侧面神经的两个外周分支，用Sugita 1号动脉瘤夹夹闭2min。通过刺激暴露的面神经近端和远端(8 mA恒流)记录诱发肌电。两个刺激点的平均距离为25 mm，分别于伤前、伤后即刻、伤后14天计算神经传导速度。将含雪旺细胞(1.0×10~(-1)d1/ml)的胶原凝胶(0.3ml)覆盖于挤压伤处10处(雪旺组)，另8处仅覆盖胶原胶(对照组)。电生理检查后，用4%多聚甲醛灌流大鼠，取出神经，石蜡包埋。取5片菊花厚切片，进行HE染色和S-100蛋白免疫细胞化学染色。基线NCV为47.6(Sy.+-)。[)6.8米/S(平均()正负)。[)SE)，伤后即刻显著降低(11.8(]SY.+-)。[)2.7米/S)。伤后14天，施万组神经传导速度为(30.3±+-)。()8.6m/S)显著高于对照组(11.2()sy.+-)。[)3.6米/S)。然而，免疫细胞化学未能显示挤压伤神经周围移植的雪旺细胞，这些结果表明，雪旺细胞移植到挤压伤面神经周围可能有助于挤压伤后早期的神经再生。然而，目前还难以确定促进受损神经修复的物质和机制。

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.