Improved materials for peripheral nerve repair are needed for the advancement of new surgical techniques in fields spanning from oncology to trauma. In this study, we developed bioresorbable materials capable of producing repeated electric field gradients spaced 600 μm apart to assess the impact on neuronal cell growth, and migration. Electrically conductive, biphasic composites comprised of poly (glycerol) sebacate acrylate (PGSA) alone, and doped with poly (pyrrole) (PPy), were prepared to create alternating segments with high and low electrically conductivity. Conductivity measurements demonstrated that 0.05% PPy added to PSA achieved an optimal value of 1.25 × 10⁻⁴ S/cm, for subsequent electrical stimulation. Tensile testing and degradation of PPy doped and undoped PGSA determined that 35–40% acrylation of PGSA matched nerve mechanical properties. Both fibroblast and neuronal cells thrived when cultured upon the composite. Biphasic PGSA/PPy sheets seeded with neuronal cells stimulated for with 3 V, 20 Hz demonstrated a 5x cell increase with 1 day of stimulation and up to a 10x cell increase with 3 days stimulation compared to non-stimulated composites. Tubular conduits composed of repeated high and low conductivity materials suitable for implantation in the rat sciatic nerve model for nerve repair were evaluated in vivo and were superior to silicone conduits. These results suggest that biphasic conducting conduits capable of maintaining mechanical properties without inducing compression injuries while generating repeated electric fields are a promising tool for acceleration of peripheral nerve repair to previously untreatable patients.

Graphical Abstract

中文翻译：

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通过重复双相导电材料进行电刺激用于周围神经再生

从肿瘤学到创伤学等领域，需要改进的周围神经修复材料来推动新外科技术的发展。在这项研究中，我们开发了能够产生间隔 600 μm 的重复电场梯度的生物可吸收材料，以评估对神经元细胞生长和迁移的影响。制备了仅由聚（甘油）癸二酸酯丙烯酸酯（PGSA）并掺杂聚（吡咯）（PPy）组成的导电双相复合材料，以形成具有高和低电导率的交替片段。电导率测量表明，添加到 PSA 中的 0.05% PPy 对于后续的电刺激达到了 1.25 × 10 ^-4 S/cm 的最佳值。PPy 掺杂和未掺杂 PGSA 的拉伸测试和降解确定 35-40% 的 PGSA 丙烯酸化与神经机械特性相匹配。当在复合材料上培养时，成纤维细胞和神经元细胞都生长旺盛。与未刺激的复合材料相比，接种了经 3 V、20 Hz 刺激的神经元细胞的双相 PGSA/PPy 片显示，刺激 1 天后细胞数量增加了 5 倍，刺激 3 天后细胞数量增加了 10 倍。由重复的高和低电导率材料组成的管状导管适合植入大鼠坐骨神经模型进行神经修复，并在体内进行了评估，并且优于硅胶导管。这些结果表明，双相传导导管能够保持机械性能而不引起压缩损伤，同时产生重复电场，是加速对先前无法治疗的患者进行周围神经修复的有前途的工具。

图形概要