Department of Chemical Engineering and Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI, 48109, USA.
State Key Lab of Food Science and Technology, International Joint Research Laboratory for Biointerface and Biodetection, and School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, P. R. China.
Adv Mater. 2018 Jan;30(1). doi: 10.1002/adma.201703343. Epub 2017 Nov 14.
Load-bearing soft tissues, e.g., cartilage, ligaments, and blood vessels, are made predominantly from water (65-90%) which is essential for nutrient transport to cells. Yet, they display amazing stiffness, toughness, strength, and deformability attributed to the reconfigurable 3D network from stiff collagen nanofibers and flexible proteoglycans. Existing hydrogels and composites partially achieve some of the mechanical properties of natural soft tissues, but at the expense of water content. Concurrently, water-rich biomedical polymers are elastic but weak. Here, biomimetic composites from aramid nanofibers interlaced with poly(vinyl alcohol), with water contents of as high as 70-92%, are reported. With tensile moduli of ≈9.1 MPa, ultimate tensile strains of ≈325%, compressive strengths of ≈26 MPa, and fracture toughness of as high as ≈9200 J m , their mechanical properties match or exceed those of prototype tissues, e.g., cartilage. Furthermore, with reconfigurable, noncovalent interactions at nanomaterial interfaces, the composite nanofiber network can adapt itself under stress, enabling abiotic soft tissue with multiscale self-organization for effective load bearing and energy dissipation.
承重的软组织，如软骨、韧带和血管，主要由水（65-90%）构成，这对营养物质向细胞的输送至关重要。然而，它们表现出惊人的刚度、韧性、强度和可变形性，这归因于由刚性胶原纳米纤维和柔性蛋白聚糖组成的可重构 3D 网络。现有的水凝胶和复合材料部分实现了天然软组织的一些机械性能，但以牺牲含水量为代价。同时，富含水的生物医学聚合物具有弹性但强度较低。在这里，报告了由芳纶纳米纤维交织的聚（乙烯醇）组成的仿生复合材料，其含水量高达 70-92%。其拉伸模量约为 9.1 MPa，极限拉伸应变约为 325%，压缩强度约为 26 MPa，断裂韧性高达约 9200 J m-1，其机械性能与原型组织（如软骨）相当或超过。此外，由于纳米材料界面上的可重构非共价相互作用，复合材料纳米纤维网络可以在应力下进行自我调整，从而实现具有多尺度自组织的非生物软组织，以有效承载和耗散能量。
