Wits Advanced Drug Delivery Platform Research Unit, Department of Pharmacy and Pharmacology, Faculty of Health Sciences, School of Therapeutic Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg 2193, South Africa.
Department of Plastic and Reconstructive Surgery, Faculty of Health Sciences, School of Clinical Medicine, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg 2193, South Africa.
Int J Mol Sci. 2021 Oct 26;22(21):11555. doi: 10.3390/ijms222111555.
Optimal levels of functional recovery in peripheral nerve injuries remain elusive due to the architectural complexity of the neuronal environment. Commercial nerve repair conduits lack essential guidance cues for the regenerating axons. In this study, the regenerative potential of a biosimulated nerve repair system providing three types of regenerative cues was evaluated in a 10 mm sciatic nerve-gap model over 4 weeks. A thermo-ionically crosslinked gellan-xanthan hydrogel conduit loaded with electrospun PHBV-magnesium oleate-N-acetyl-cysteine (PHBV-MgOl-NAC) nanofibers was assessed for mechanical properties, nerve growth factor (NGF) release kinetics and PC12 viability. In vivo functional recovery was based on walking track analysis, gastrocnemius muscle mass and histological analysis. As an intraluminal filler, PHBV-MgOl-NAC nanofibers improved matrix resilience, deformation and fracture of the hydrogel conduit. NGF release was sustained over 4 weeks, governed by Fickian diffusion and Case-II relaxational release for the hollow conduit and the nanofiber-loaded conduit, respectively. The intraluminal fibers supported PC12 proliferation by 49% compared to the control, preserved up to 43% muscle mass and gradually improved functional recovery. The combined elements of physical guidance (nanofibrous scaffolding), chemical cues (N-acetyl-cysteine and magnesium oleate) and therapeutic cues (NGF and diclofenac sodium) offers a promising strategy for the regeneration of severed peripheral nerves.
由于神经元环境的结构复杂性,外周神经损伤的最佳功能恢复水平仍然难以实现。商业神经修复导管缺乏对再生轴突的必要引导线索。在这项研究中,在 10mm 坐骨神经间隙模型中,通过提供三种再生线索的仿生神经修复系统评估了再生潜力,持续 4 周。评估了负载静电纺丝 PHBV-油酸钠-N-乙酰半胱氨酸(PHBV-MgOl-NAC)纳米纤维的热离子交联结冷胶-黄原胶水凝胶导管的机械性能、神经生长因子(NGF)释放动力学和 PC12 活力。体内功能恢复基于行走轨迹分析、比目鱼肌质量和组织学分析。作为管腔内填充物,PHBV-MgOl-NAC 纳米纤维改善了水凝胶导管的基质弹性、变形和断裂。NGF 释放持续 4 周,分别由中空导管和负载纳米纤维的导管的菲克扩散和案例 II 松弛释放控制。与对照相比,管腔内纤维使 PC12 增殖增加了 49%,保持了高达 43%的肌肉质量,并逐渐改善了功能恢复。物理引导(纳米纤维支架)、化学线索(N-乙酰半胱氨酸和油酸钠)和治疗线索(NGF 和双氯芬酸钠)的组合元素为切断的周围神经再生提供了有前途的策略。