Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK.
Oxford Biomaterials Ltd., Unit 15, Calaxy House, Newbury, RG19 6HR, UK.
Sci Rep. 2017 Oct 23;7(1):13790. doi: 10.1038/s41598-017-14280-5.
One of the most challenging applications for tissue regeneration is spinal cord damage. There is no cure for this, partly because cavities and scar tissue formed after injury present formidable barriers that must be crossed by axons to restore function. Natural silks are considered increasingly for medical applications because they are biocompatible, biodegradable and in selected cases promote tissue growth. Filaments from wild Antheraea pernyi silkworms can support axon regeneration in peripheral nerve injury. Here we presented evidence that degummed A. pernyi filaments (DAPF) support excellent outgrowth of CNS neurons in vitro by cell attachment to the high density of arginine-glycine-aspartic acid tripeptide present in DAPF. Importantly, DAPF showed stiffness properties that are well suited to spinal cord repair by supporting cell growth mechano-biology. Furthermore, we demonstrated that DAPF induced no activation of microglia, the CNS resident immune cells, either in vitro when exposed to DAPF or in vivo when DAPF were implanted in the cord. In vitro DAPF degraded gradually with a corresponding decrease in tensile properties. We conclude that A. pernyi silk meets the major biochemical and biomaterial criteria for spinal repair, and may have potential as a key component in combinatorial strategies for spinal repair.
组织再生最具挑战性的应用之一是脊髓损伤。目前还没有治愈方法，部分原因是损伤后形成的空洞和疤痕组织构成了难以逾越的障碍，轴突必须穿过这些障碍才能恢复功能。天然丝越来越多地被用于医学应用，因为它们具有生物相容性、可生物降解性，并且在某些情况下可以促进组织生长。野桑蚕的丝纤维可以支持周围神经损伤中的轴突再生。在这里，我们提供的证据表明，脱胶野桑蚕丝纤维（DAPF）通过细胞附着在 DAPF 中存在的高密度精氨酸-甘氨酸-天冬氨酸三肽上，支持中枢神经系统神经元的体外良好生长。重要的是，DAPF 表现出的刚度特性非常适合通过支持细胞生长机械生物学来修复脊髓。此外，我们证明，DAPF 既没有在体外暴露于 DAPF 时激活小胶质细胞（中枢神经系统常驻免疫细胞），也没有在 DAPF 植入脊髓时激活小胶质细胞。在体外，DAPF 逐渐降解，同时拉伸性能相应下降。我们得出的结论是，野桑蚕丝满足了脊髓修复的主要生化和生物材料标准，并且可能作为组合策略修复脊髓的关键组成部分具有潜力。
