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构建用导电纤维填充的导电导管应用于周围神经再生修复
Chemical Engineering Journal 345 (2018) 566–577 神经导管对于引导受损的周围神经的再生是必不可少的，并且由于细胞迁移和营养物运输的问题，空导管通常不能很好的发挥作用。考虑到神经组织的电生理特征，在该研究中，构建了填充有平行排列的导电纤维的导电导管，并且在体内评估了其增强周围神经再生的潜力。导电纤维是通过将一个聚吡咯壳沉积在取向的静电纺丝PLGA纤维上制备的。导电管道是通过一个芯棒上的涂膜涂层来制作的。这两种材料对PC12细胞都没有细胞毒性，并且能够促进细胞增殖和分化。此外，取向的纤维为神经纤维提供了很强定向引导。在Sprague-Dawley大鼠中产生坐骨神经缺损，并将空的或纤维填充的导管缝合到缺损中。同时， PLGA导管或自体移植物为对照组。术后12周，纤维填充导管显示出比PLGA导管和空导管更好的神经再生结果，并且在电生理特性，坐骨神经功能指数和再生有髓神经纤维以及轴突直径和髓鞘厚度方面显示出与自体移植相当的结果。由于它们的传输能力，导电导管中的取向导电纤维可能为神经生长提供有利的微环境。 Nerve conduits are essential for guiding the regeneration of injured peripheral nerves, and empty conduits usually cannot perform satisfactorily due to problems with cell migration and nutrient transportation. Taking the electrophysiological features of nervous tissues into consideration, in this study, a conductive conduit filled with parallel-aligned conductive fibers was constructed, and its potential for enhancing peripheral nerve regeneration was evaluated in vivo. The conductive fibers were prepared via depositing a polypyrrole (PPY) shell onto electrospun parallel-aligned poly(lactide-co-glycolide) (PLGA) fibers. The conductive conduit was prepared from PLGA/PPY emulsion via dip-coating on a mandrel. Both materials were non-cytotoxic to PC12 cells and were able to promote cell proliferation and differentiation. Moreover, the aligned fibers provided strong orientation guidance for nerve fibers. Sciatic nerve defects were created in Sprague-Dawley rats, and empty or fiber-filled conduits were sutured into the defects. Meanwhile, the control groups received PLGA conduits or autografts. Twelve weeks post-operation, the fiber-filled conductive conduit showed much better nerve regeneration outcomes than both the PLGA conduit and the empty conductive conduit and showed comparable results to the autograft in terms of electrophysiological properties, sciatic function indices, and regenerated myelinated nerve fibers as well as axon diameter and myelin thickness. It is possible that the oriented conductive fibers in the conductive conduit provide a favorable micro-environment for nerve growth due to their capacity to transmit. （张守燕）
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