Development and evaluation of artificial nerve which could enhance axonal elongation in peripheral and central nervous system

从棕色海藻中提取的海藻酸盐以共价键进行化学交联。海藻酸盐的初始浓度和辐射剂量可以控制生物降解速度。对于周围神经修复，猫的坐骨神经缺损处使用藻酸盐海绵桥接，这种海绵是专门设计的，可以在3个月内生物降解。术后3个月，缝隙中央可见大量再生轴突。电生理上，电刺激缝隙近端的坐骨神经，可在腓肠肌记录到肌肉动作电位。在大鼠坐骨神经缝隙模型中，可见再生轴突出现在生物降解的藻酸盐中，这种藻酸盐不具有海绵结构。将冻干海绵植入大鼠脊髓间隙，用于中枢神经修复。在植入的藻酸盐和宿主脊髓中可见再生的轴突，HRP-示踪研究表明。电生理学上，记录到缝隙以外的动作电位。接下来，从表达绿色荧光蛋白(GFP)的转基因大鼠胚胎中制备海马源性神经球，并将其移植到幼年大鼠脊髓充满藻酸盐的损伤中。移植后1周、2周和4周，大量移植细胞存活，其中许多细胞表达胶质纤维酸性蛋白，少数细胞表达β-微管蛋白。这些结果表明，大鼠胚胎海马区来源的神经球细胞可以存活、分化并与宿主脊髓组织融合良好。

Alginate, derived from brown seaweeds was chemically crosslinked with covalent bond. Biodegradation speed can be controlled by initial concentration of alginate and dose of irradiation. For peripheral nerve repair, sciatic nerve gap in the cats was bridged using alginate sponge, which was specially designed to biodegradate within 3 months. Three months after operation, many regenerated axon were found in the middle of the gap. Electrophysiologically, muscle action potentials could be recorded at the gastrocnemius muscle after electrical stimulation of the sciatic nerve proximal to the gap. Rat sciatic nerve gap model, regenerating axons can be seen in the biodegrading alginate, which does not have sponge structure. For central nerve repair, freeze-dried alginate sponge was implanted into the gap of rat spinal cord. Regenerating axons was seen in the implanted alginate and in the host spinal cord, which was examined by HRP-tracing study. Electrophysiologically, action potential was recorded beyond the gap. Next, hippocampus-derived neurospheres were prepared from transgenic rat fetuses expressing green fluorescent protein (GFP), and transplanted into an alginate-filled lesion of young rat spinal cord. One, two and four weeks after transplantation, a large number of grafted cells survived, many of which expressed immunoreactiveity for glial fibrillary acidic protein, and a few expressed immunoreactiveity for beta-tubulin These findings demonstrate that rat fetal hippocampus-derived neurosphere cells could survive, differentiate, and integrate well into the host spinal cord tissue.