Jiang Xu, Mi Ruifa, Hoke Ahmet, Chew Sing Yian
Nanyang Technological University, School of Chemical & Biomedical Engineering, Singapore, 637459, Singapore.
J Tissue Eng Regen Med. 2014 May;8(5):377-85. doi: 10.1002/term.1531. Epub 2012 Jun 15.
Fibre structures represent a potential class of materials for the formation of synthetic nerve conduits due to their biomimicking architecture. Although the advantages of fibres in enhancing nerve regeneration have been demonstrated, in vivo evaluation of fibre size effect on nerve regeneration remains limited. In this study, we analyzed the effects of fibre diameter of electrospun conduits on peripheral nerve regeneration across a 15-mm critical defect gap in a rat sciatic nerve injury model. By using an electrospinning technique, fibrous conduits comprised of aligned electrospun poly (ε-caprolactone) (PCL) microfibers (981 ± 83 nm, Microfiber) or nanofibers (251 ± 32 nm, Nanofiber) were obtained. At three months post implantation, axons regenerated across the defect gap in all animals that received fibrous conduits. In contrast, complete nerve regeneration was not observed in the control group that received empty, non-porous PCL film conduits (Film). Nanofiber conduits resulted in significantly higher total number of myelinated axons and thicker myelin sheaths compared to Microfiber and Film conduits. Retrograde labeling revealed a significant increase in number of regenerated dorsal root ganglion sensory neurons in the presence of Nanofiber conduits (1.93 ± 0.71 × 10(3) vs. 0.98 ± 0.30 × 10(3) in Microfiber, p < 0.01). In addition, the compound muscle action potential (CMAP) amplitudes were higher and distal motor latency values were lower in the Nanofiber conduit group compared to the Microfiber group. This study demonstrated the impact of fibre size on peripheral nerve regeneration. These results could provide useful insights for future nerve guide designs.
由于其仿生结构，纤维结构代表了一类潜在的用于合成神经导管形成的材料。尽管纤维在促进神经再生方面的优势已得到证实，但纤维尺寸对神经再生的体内评估仍然有限。在本研究中，我们在大鼠坐骨神经损伤模型中分析了电纺导管的纤维直径对15毫米关键缺损间隙周围神经再生的影响。通过使用电纺技术，获得了由排列的电纺聚（ε-己内酯）（PCL）微纤维（981±83纳米，微纤维）或纳米纤维（251±32纳米，纳米纤维）组成的纤维导管。植入后三个月，所有接受纤维导管的动物的轴突均跨越缺损间隙再生。相比之下，在接受空的、无孔PCL薄膜导管（薄膜）的对照组中未观察到完全的神经再生。与微纤维和薄膜导管相比，纳米纤维导管导致有髓轴突总数显著增加且髓鞘更厚。逆行标记显示，在存在纳米纤维导管的情况下，再生的背根神经节感觉神经元数量显著增加（微纤维组为0.98±0.30×10³，纳米纤维组为1.93±0.71×10³，p<0.01）。此外，与微纤维组相比，纳米纤维导管组的复合肌肉动作电位（CMAP）幅度更高，远端运动潜伏期值更低。本研究证明了纤维尺寸对周围神经再生的影响。这些结果可为未来的神经导向设计提供有用的见解。
