International Center for Spinal Cord Injury, Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, MD 21205, USA.
Biomaterials. 2011 Sep;32(26):6068-79. doi: 10.1016/j.biomaterials.2011.05.006. Epub 2011 Jun 1.
Following spinal cord injury, axons fail to regenerate without exogenous intervention. In this study we report that aligned microfiber-based grafts foster robust regeneration of vascularized CNS tissue. Film, random, and aligned microfiber-based conduits were grafted into a 3 mm thoracic rat spinal cord gap created by complete transection. Over the course of 4 weeks, microtopography presented by aligned or random poly-L-lactic acid microfibers facilitated infiltration of host tissue, and the initial 3 mm gap was closed by endogenous cell populations. This bulk tissue response was composed of regenerating axons accompanied by morphologically aligned astrocytes. Aligned fibers promoted long distance (2055 ± 150 μm), rostrocaudal axonal regeneration, significantly greater than random fiber (1162 ± 87 μm) and film (413 ± 199 μm) controls. Retrograde tracing indicated that regenerating axons originated from propriospinal neurons of the rostral spinal cord, and supraspinal neurons of the reticular formation, red nucleus, raphe and vestibular nuclei. Our findings outline a form of regeneration within the central nervous system that holds important implications for regeneration biology.
脊髓损伤后，如果没有外源性干预，轴突就无法再生。在这项研究中，我们报告了排列整齐的微纤维基移植物促进了血管化中枢神经系统组织的强大再生。将薄膜、随机和排列的微纤维基导管移植到通过完全横断造成的 3 毫米胸段大鼠脊髓间隙中。在 4 周的时间里，排列或随机的聚 L-乳酸微纤维呈现的微形貌促进了宿主组织的渗透，并且最初的 3 毫米间隙被内源性细胞群封闭。这种大块组织反应由再生轴突组成，伴随着形态上排列整齐的星形胶质细胞。排列的纤维促进了长距离（2055 ± 150 μm）、头尾向轴突再生，明显大于随机纤维（1162 ± 87 μm）和薄膜（413 ± 199 μm）对照组。逆行追踪表明，再生轴突起源于头端脊髓的固有脊髓神经元和网状结构、红核、中缝核和前庭核的上位神经元。我们的发现概述了中枢神经系统内的一种再生形式，对再生生物学具有重要意义。
