Nerve guidance conduits (NGCs) have the potential to replace autografts in repairing peripheral nerve injuries, but their efficacy still needs to be improved. The efficacy of NGCs is augmented by neurotrophic factors that promote axon growth and by enzymes capable of degrading molecules that inhibit axon growth. In the current study, two types of NGCs loaded with factors (both neurotrophin‐3 and chondroitinase ABC) are constructed and their abilities to repair an 8 mm gap in the rat sciatic nerve are examined. The factors are encapsulated in microparticles made of a phase‐change material (PCM) or collagen and then sandwiched between two layers of electrospun fibers. The use of PCM allows to achieve pulsed release of the factors upon irradiation with a near‐infrared laser. The use of collagen enables slow, continuous release via diffusion. The efficacy is evaluated by measuring compound muscle action potentials (CMAP) in the gastrocnemius muscle and analyzing the nerve histology. Continuous release of the factors from collagen results in enhanced CMAP amplitude and increased axon counts in the distal nerve relative to the plain conduit. In contrast, pulsed release of the same factors from PCM shows a markedly adverse impact on the efficacy, possibly by inhibiting axon growth.

中文翻译：

---

控制 Neurotrophin-3 和软骨素酶 ABC 的释放可增强神经引导导管的功效。

神经引导导管（NGC）有可能替代自体移植物修复周围神经损伤，但其疗效仍有待提高。促进轴突生长的神经营养因子和能够降解抑制轴突生长的分子的酶增强了 NGC 的功效。在目前的研究中，构建了两种负载因子（神经营养因子-3 和软骨素酶 ABC）的 NGC，并检查了它们修复大鼠坐骨神经 8 mm 间隙的能力。这些因子被封装在由相变材料 (PCM) 或胶原蛋白制成的微粒中，然后夹在两层电纺纤维之间。PCM的使用允许在用近红外激光照射时实现因子的脉冲释放。胶原蛋白的使用能够通过扩散缓慢、持续地释放。通过测量腓肠肌中的复合肌肉动作电位 (CMAP) 并分析神经组织学来评估疗效。胶原蛋白中因子的持续释放导致 CMAP 振幅增强，并且相对于普通导管，远端神经中的轴突计数增加。相比之下，PCM 中相同因子的脉冲释放显示出对疗效的显着不利影响，可能是通过抑制轴突生长。