Department of Urology, University Hospital Zurich, 8091 Zurich, Switzerland.
J Control Release. 2012 Jul 20;161(2):274-82. doi: 10.1016/j.jconrel.2011.11.036. Epub 2011 Dec 8.
Artificial nerve conduits (NCs) are, in certain cases, instrumental for repairing damaged peripheral nerves, although therapeutic efficacy remains often suboptimal. Considerable efforts have been made to improve the therapeutic performance of NCs. This article reviews recent developments in NC-technology for peripheral nerve regeneration with a main focus on growth factors delivery systems and repair strategies. Commonly used materials for NC fabrication include collagen, silk fibroin, and biodegradable aliphatic polyesters. The basic NC structure, i.e., a hollow tube, can be manufactured by diverse methods: spinning mandrel technology, sheet rolling, injection-molding, freeze-drying, and electro-spinning. Polymeric and cellular delivery systems for growth factors can be integrated in the NC wall or within luminal structures such as gels, fibers, or biological materials providing binding affinity for the bioactive compounds. NCs with sustained growth factor delivery generally improve significantly the axonal outgrowth in nerve defect models, although restoration of sensory and motor functions remains inferior to that achieved with autologous nerve grafts. To improve therapeutic outcomes, further biofunctionalization of NCs will be needed, i.e., adjusting degradation kinetics of NC scaffolding to be compatible with axonal regeneration; delivering multiple growth factors at individually optimized kinetics; incorporating modality specific glial cells and furnishing NCs with guiding nanostructures.
人工神经导管（NCs）在某些情况下有助于修复受损的周围神经，但治疗效果往往仍不尽如人意。人们已经做出了相当大的努力来提高 NC 的治疗性能。本文主要关注生长因子传递系统和修复策略，综述了用于周围神经再生的 NC 技术的最新进展。常用于 NC 制造的材料包括胶原蛋白、丝素纤维和可生物降解的脂肪族聚酯。NC 的基本结构，即空心管，可以通过多种方法制造：纺丝芯棒技术、片材滚压、注塑、冷冻干燥和静电纺丝。聚合物和细胞生长因子传递系统可以整合到 NC 壁或管腔结构中，如凝胶、纤维或生物材料，为生物活性化合物提供结合亲和力。具有持续生长因子传递的 NC 通常可显著改善神经缺损模型中的轴突生长，但感觉和运动功能的恢复仍不如自体神经移植物。为了提高治疗效果，需要进一步对 NC 进行生物功能化，即调整 NC 支架的降解动力学使其与轴突再生相兼容；以单独优化的动力学递呈多种生长因子；结合特定模式的神经胶质细胞，并为 NC 提供引导纳米结构。
