The C5-C6 nerve roots are usually spared from avulsion after brachial plexus injury (BPI) and can thus be used as donors for nerve repair. A BPI rat model with C5-C6 nerve root stumps has been established in our previous work. The aim of this study was to test whether riluzole loaded into a thermosensitive hydrogel could applied locally in the nerve root stumps of this BPI rat model, thus increasing the reparative effect of the nerve root stumps. Nile red (a hydrophobic dye) was used as a substitute for riluzole since riluzole itself does not emit light. Nile red, loaded into a thermosensitive hydrogel, was added to the nerve root stumps of the BPI rat model. Additionally, eighteen rats, with operation on right brachial plexus, were evenly divided into three groups: control (Con), thermosensitive hydrogel (Gel) and thermosensitive hydrogel loaded with riluzole (Gel + Ri) groups. Direct nerve repair was performed after local riluzole release for two weeks. Functional and electrophysiological evaluations and histological assessments were used to evaluate the reparative effect 8 weeks after nerve repair. Nile red was slowly released from the thermosensitive hydrogel and retrograde transport through the nerve root stumps to the motoneurons, according to immunofluorescence. Discernible functional recovery began earlier in the Gel + Ri group. The compound muscle action potential, ChAT-expressing motoneurons, positivity for neurofilaments and S100, diameter of regenerating axons, myelin sheath thickness and density of myelinated fibers were markedly increased in the Gel + Ri group compared with the Con and Gel groups. Our results indicate that the local administration of riluzole could undergo retrograde transportation through C5-C6 nerve root stumps, thereby promoting neuroprotection and increasing nerve regeneration.

C5-C6 神经根在臂丛神经损伤 (BPI) 后通常不会发生撕脱，因此可用作神经修复的供体。在我们之前的工作中已经建立了具有 C5-C6 神经根残端的 BPI 大鼠模型。本研究的目的是测试加载到热敏水凝胶中的利鲁唑是否可以局部应用于该BPI大鼠模型的神经根残端，从而增加神经根残端的修复效果。尼罗红（一种疏水性染料）被用作利鲁唑的替代品，因为利鲁唑本身不发光。将加载到热敏水凝胶中的尼罗红添加到 BPI 大鼠模型的神经根残端。此外，18只右臂丛神经手术的大鼠被平均分为三组：对照组（Con），热敏水凝胶 (Gel) 和负载利鲁唑 (Gel + Ri) 基团的热敏水凝胶。在局部利鲁唑释放两周后进行直接神经修复。功能和电生理学评估和组织学评估用于评估神经修复后 8 周的修复效果。根据免疫荧光，尼罗红从热敏水凝胶中缓慢释放出来，并通过神经根残端逆行运输到运动神经元。Gel + Ri 组较早开始明显的功能恢复。与 Con 和 Gel 组相比，Gel + Ri 组的复合肌肉动作电位、表达 ChAT 的运动神经元、神经丝和 S100 阳性、再生轴突直径、髓鞘厚度和有髓纤维密度显着增加。