Characterizing the degradation of alginate hydrogel for use in multilumen scaffolds for spinal cord repair

Alginate was studied as a degradable nerve guidance scaffold material in vitro and in vivo. In vitro degradation rates were determined using rheology to measure the change in shear modulus vs time. The shear modulus decreased from 155 kPa to 5 kPa within 2 days; however, alginate samples maintained their superficial geometry for over 28 days. The degradation behavior was supported by materials characterization data showing alginate consisted of high internal surface area (400 m(2)/g), which likely facilitated the release of cross-linking cations resulting in the rapid decrease in shear modulus. To assess the degradation rate in vivo, multilumen scaffolds were fabricated using a fiber templating technique. The scaffolds were implanted in a 2-mm-long T3 full transection rodent spinal cord lesion model for 14 days. Although there was some evidence of axon guidance, in general, alginate scaffolds degraded before axons could grow over the 2-mm-long lesion. Enabling alginate-based scaffolds for nerve repair will likely require approaches to slow its degradation. (c) 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 611-619, 2016.

海藻酸盐作为一种可降解的神经引导支架材料在体内和体外进行了研究。利用流变学测量剪切模量随时间的变化来确定体外降解速率。剪切模量在2天内从155 kPa降至5 kPa；然而，海藻酸盐样品在28天以上仍保持其表面形态。材料表征数据支持了这种降解行为，该数据显示海藻酸盐具有高的内表面积（400平方米/克），这可能促进了交联阳离子的释放，从而导致剪切模量迅速下降。为了评估体内降解速率，采用纤维模板技术制备了多腔支架。将支架植入2毫米长的T3完全横断啮齿动物脊髓损伤模型中14天。尽管有一些轴突引导的证据，但总体而言，海藻酸盐支架在轴突能够在2毫米长的损伤区域生长之前就已降解。要使基于海藻酸盐的支架用于神经修复，可能需要采取措施减缓其降解。（c）2015威利期刊公司。《生物医学材料研究A部分》：104A：611 - 619，2016年。