The major problem in peripheral nerve repair is restoration of the microenvironment rather than traditional structural reconstruction. Nanodiamonds (NDs), highly biocompatible carbon nanoparticles, are widely applied in medical engineering. They may alleviate inflammatory insults in peripheral nerve injury because they can induce macrophage polarization from a proinflammatory to an anti-inflammatory state. Here we report a concentric multilayered spraying manufacturing process to fabricate microporous ND/polycaprolactone (PCL) nerve bridges. We investigated the proliferative, adhesive, and glioprotective role of these bridges in Schwann cells in vitro. We further evaluated their long-term in vivo performance in a 20-mm sciatic nerve defect rat model. ND/PCL nerve bridges are comparable to autografts in functional, electrophysiological, and morphological sciatic nerve repair. They ameliorate the immune milieu by inducing M1 to M2 macrophage polarization. In addition, they pose no harm to major organs after 4 months of implantation. These findings show the promising roles of ND-based nanotechnology in neuroengineering.

周围神经修复的主要问题是微环境的恢复，而不是传统的结构重建。纳米金刚石（NDs）是具有高度生物相容性的碳纳米颗粒，已广泛应用于医学工程。它们可以减轻外周神经损伤中的炎症损伤，因为它们可以诱导巨噬细胞极化，从促炎状态转变为消炎状态。在这里，我们报告同心的多层喷涂制造工艺来制造微孔ND /聚己内酯（PCL）神经桥。我们调查了这些桥在体外的施万细胞中的增殖，粘附和胶质保护作用。我们进一步评估了它们在20毫米坐骨神经缺损大鼠模型中的长期体内表现。ND / PCL神经桥在功能，电生理，和坐骨神经形态修复。它们通过诱导M1至M2巨噬细胞极化来改善免疫环境。此外，它们在植入四个月后对主要器官无害。这些发现表明基于ND的纳米技术在神经工程中的有前途的作用。