异种神经基膜管桥接周围神经缺损的初步研究

REPAIR OF PERIPHERAL NERVE DEFECT BY XENOGENEIC ACELLULAR NERVE BASAL LAMINA SCAFFOLDS

目的 探索经化学萃取的去细胞神经基膜管支架用于异种移植桥接周围神经缺损的可行性。方法 SD大鼠 30只 ,随机分为 5组 ,分别制作预溃变 2周 (溃变支架桥接组 )和新鲜的兔胫神经进行化学萃取 ,形成去细胞神经基膜管支架 (异体支架桥接组 ) ,兔新鲜胫神经束 (异种神经移植组 ) ;切取自体神经 15 mm原位移植 (自体神经移植组 ) ,修复大鼠坐骨神经长 15 mm的缺损。坐骨神经切断后不作移植修复 ,为对照组。术后 6个月行坐骨神经功能指数 (SFI)测定和疼痛试验 ,用美蓝染色、免疫组织化学、透射电镜等方法对吻合口、移植体中央和远侧神经段的再生神经纤维进行形态学观察 ,并对再生有髓纤维的数量、直径及髓鞘厚度等进行量化分析。结果 术后 3个月 ,仅有溃变支架桥接组、支架桥接组和自体神经移植组动物患肢行走逐渐恢复。 6个月时 ,针刺患足可引起背部肌肉收缩和下肢屈曲反应 ;术后 6个月行 SFI检测 ,溃变支架桥接组为 - 36 .2 %± 9.7% ,支架桥接组为 - 30 .7%± 6 .8% ,自体神经移植组为 - 33.9%±11.3% ,各组间比较无统计学意义 (P>0 .0 5 )。组织学观察见溃变支架桥接组与支架桥接组移植体中央横切面再生神经呈微束状分布。透射电镜观察见再生神经纤维具有正常的形态和结构。图像分析结果显示溃变支架?

Objective To explore the possibility to bridge peripheral nerve defects by xenogeneic acellular nerve basal lamina scaffolds. Methods Thirty SD rats were randomly divided into 5 groups; in each group, the left sciatic nerves were bridged respectively by predegenerated or fresh xenogeneic acellular nerve basal lamina scaffolds, autogenous nerve grafting, fresh xenogeneic nerve grafting or without bridging. Two kinds of acellular nerve basal lamina scaffolds, extracted by 3% Triton X 100 and 4% deoxycholate sodium from either fresh rabbit tibial nerves or predegenerated ones for 2 weeks, were transplanted to bridge 15 mm rat sciatic nerve gaps. Six months after the grafting, the recovery of function was evaluated by gait analysis, pinch test, morphological and morphometric analysis. Results The sciatic nerve function indexes (SFI) were -30.7% ±6.8% in rats treated with xenogeneic acellular nerve, -36.2%± 9.7% with xenogeneic predegenerated acellular nerve, and -33.9%±11.3% with autograft respectively ( P >0.05). The number of regenerative myelinated axons, diameter of myelinated fibers and thickness of myelin sheath in acellular xenograft were satisfactory when compared with that in autograft. Regenerated microfascicles distributed in the center of degenerated and acellular nerve group. The regenerated nerve fibers had normal morphological and structural characters under transmission electron microscope. The number and diameter of myelinated fibers in degenerated accellular nerve group was similar to that of autograft group (P>0.05). Whereas the thickness of myelin sheath in degenerated accellular nerve group was significantly less than that of autograft group( P <0.05). Conclusion The above results indicate that xenogeneic acellular nerve basal lamina scaffolds extracted by chemical procedure can be successfully used to repair nerve defects without any immunosuppressants.