Peripheral nerve regeneration by transplantation of BMSC-derived Schwann cells as chitosan gel sponge scaffolds

It is said that bone marrow stromal cells (BMSCs) are able to differentiate into different kinds of cells, including Schwann cells, under relevant conditions (Dezawa et al., Eur J Neurosci 2001,14:1771-1776). In the previous paper, we demonstrated that chitosan gel sponge is one of the effective scaffolds for regenerating axons of the rat sciatic nerve (Ishikawa et al., J Biomed Mater Res A 2007;83:33-40). In the present study, we examined whether BMSC-derived Schwann cells with chitosan gel sponges were one of the effective scaffolds for peripheral nerve regeneration in rats. BMSC-derived cells with Schwann cell characteristics were labeled by green fluorescent protein using a retrovirus. An 8-mm gap was made by removing a nerve segment from the rat peripheral nerve, and chitosan gel sponges containing BMSC-derived Schwann cells were grafted, sandwiching the proximal and distal stumps of the transected nerve. Rats were sacrificed at 7, 14, and 28 days, and 2 and 4 months after transplantation. Immunohistochemistry demonstrated that regenerating axons were found near transplanted Schwann cells 7 days after surgery and extended into the host distal nerve segment at 14 days after surgery. Electron microscopy showed that transplanted Schwann cells formed myelin sheaths on regenerating axons 1 month after transplantation. The mean diameter of myelinated fibers was increased from 2.58 mu m at 2 months to 2.84 mu m at 4 months postsurgery. This Study indicates that chitosan gel sponges containing BMSC-derived Schwann cells have strong potentiality as a graft that can be used for peripheral nerve regeneration. (C) 2009 Wiley Periodicals, Inc. J Biomed Mater Res 89A: 1118-1124, 2009

据说骨髓基质细胞（BMSCs）在相关条件下能够分化为不同种类的细胞，包括施万细胞（Dezawa等人，《欧洲神经科学杂志》2001年，14卷：1771 - 1776页）。在之前的论文中，我们证明了壳聚糖凝胶海绵是大鼠坐骨神经轴突再生的有效支架之一（Ishikawa等人，《生物医学材料研究杂志A辑》2007年；83卷：33 - 40页）。在本研究中，我们检验了含有壳聚糖凝胶海绵的骨髓基质细胞衍生的施万细胞是否是大鼠周围神经再生的有效支架之一。利用逆转录病毒，用绿色荧光蛋白标记具有施万细胞特征的骨髓基质细胞衍生细胞。通过从大鼠周围神经去除一段神经制造一个8毫米的间隙，将含有骨髓基质细胞衍生施万细胞的壳聚糖凝胶海绵进行移植，夹在切断神经的近端和远端残端之间。在移植后7天、14天、28天以及2个月和4个月处死大鼠。免疫组织化学显示，术后7天在移植的施万细胞附近发现再生轴突，术后14天延伸到宿主远端神经段。电子显微镜显示，移植后1个月，移植的施万细胞在再生轴突上形成髓鞘。有髓纤维的平均直径从术后2个月的2.58微米增加到术后4个月的2.84微米。本研究表明，含有骨髓基质细胞衍生施万细胞的壳聚糖凝胶海绵作为可用于周围神经再生的移植物具有很大潜力。（C）2009威利期刊公司。《生物医学材料研究杂志》89A辑：1118 - 1124页，2009年