Peripheral nerve injury (PNI) is the most common neurological injury in civilian and military injuries, with over 360,000 PNI procedures performed in the US yearly. Segmental loss of nerve tissue results in a nerve gap precluding a tension-free primary repair, and in these cases, interpositional autologous or acellular nerve allografts are used to bridge the gap. Graft ischemia time is a critical factor in achieving satisfactory nerve regeneration. Rapid nerve graft revascularization is essential in order to sustain Schwann cell growth which in turn is crucial for axonal regeneration. Currently, nerve autografts are considered the gold standard for segmental nerve gaps but are associated with several disadvantages such as limited supply of expendable donor tissue, increased operative time, and donor site morbidity. Hence, readily available, off-the-shelf nerve allografts or scaffolds are being investigated since they provide advantages such as a virtually limitless sourcing, a wide variety of sizes to match recipient nerves, and no donor site morbidity. New, exciting advances in tissue engineering to augment revascularization of nerve allografts or conduits have been investigated. Strategies include pro-angiogenic mesenchymal stem cells, extracellular vesicles, functionalized scaffolds, bioactive peptides, and three-dimensional bioprinting. This article discusses these bioengineering advances and future strategies aimed at enhancing nerve graft and scaffold revascularization. This article is categorized under: Neurological Diseases > Biomedical Engineering Neurological Diseases > Molecular and Cellular Physiology.

中文翻译：

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神经移植血运重建的生物工程方法：当前概念和未来方向。

周围神经损伤 (PNI) 是民用和军事损伤中最常见的神经损伤，美国每年进行超过 360,000 例 PNI 手术。神经组织的节段性损失导致神经间隙，妨碍无张力初次修复，在这些情况下，使用插入式自体或无细胞同种异体神经移植物来桥接间隙。移植物缺血时间是实现令人满意的神经再生的关键因素。快速神经移植血运重建对于维持雪旺细胞生长至关重要，而雪旺细胞生长又对轴突再生至关重要。目前，自体神经移植被认为是节段神经间隙的金标准，但存在一些缺点，例如消耗性供体组织的供应有限、手术时间增加和供体部位发病率。因此，随手可得，现成的神经同种异体移植物或支架正在受到研究，因为它们具有诸如几乎无限的来源、多种尺寸以匹配受体神经以及无供体部位发病率等优点。人们已经研究了组织工程方面令人兴奋的新进展，以增强神经同种异体移植物或导管的血运重建。策略包括促血管生成间充质干细胞、细胞外囊泡、功能化支架、生物活性肽和三维生物打印。本文讨论了这些生物工程进展和旨在增强神经移植和支架血运重建的未来策略。本文分类为：神经系统疾病 > 生物医学工程神经系统疾病 > 分子和细胞生理学。