National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou 215123, People's Republic of China.
Acta Biomater. 2013 Nov;9(11):8991-9003. doi: 10.1016/j.actbio.2013.06.045. Epub 2013 Jul 9.
A major block in the development of small diameter vascular grafts is achieving suitable blood vessel regeneration while minimizing the risk of thrombosis, intimal hyperplasia, suture retention, and mechanical failure. Silk-based tubular vessels for tissue engineering have been prepared by molding, dipping, electrospinning, or gel spinning, however, further studies are needed to improve the mechanical and blood compatibility properties. In the present study a bilayered vascular graft based on silk fibroin (SF) was developed. The graft was composed of an inner silk fiber-reinforced SF tube containing heparin and a highly porous SF external layer. Compared with previously fabricated SF tubes the fiber-reinforcement provided a comparable or higher mechanical strength, burst pressure, and suture retention strength, as well as mechanical compliance, to saphenous veins for vascular grafts. Heparin release was sustained for at least 1 month, affording blood compatibility to the grafts. The outer layer of the grafts prepared through lyophilization had a highly porous structure in which the macropore walls were composed of nanofibers similar to extracellular matrix, which offered an excellent environment for cell growth. In vitro studies showed good cytocompatibility and hemocompatibility.
小直径血管移植物发展的主要障碍是在最小化血栓形成、内膜增生、缝线保留和机械失效风险的同时实现合适的血管再生。已经通过模制、浸渍、静电纺丝或凝胶纺丝制备了用于组织工程的基于丝素（SF）的管状血管，然而，需要进一步的研究来改善机械和血液相容性。在本研究中，开发了一种基于丝素纤维（SF）的双层血管移植物。移植物由含有肝素的内部丝纤维增强 SF 管和高度多孔的 SF 外层组成。与之前制造的 SF 管相比，纤维增强提供了相当或更高的机械强度、爆裂压力和缝线保留强度，以及机械顺应性，以适应血管移植物的大隐静脉。肝素的释放至少持续 1 个月，赋予移植物血液相容性。通过冷冻干燥制备的移植物的外层具有高度多孔的结构，其中大孔壁由类似于细胞外基质的纳米纤维组成，为细胞生长提供了极好的环境。体外研究表明具有良好的细胞相容性和血液相容性。
