Sun Wenxu, Xue Bin, Fan Qiyang, Tao Runhan, Wang Chunxi, Wang Xin, Li Yiran, Qin Meng, Wang Wei, Chen Bin, Cao Yi
Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructure, and Department of Physics, Nanjing University, Nanjing 210093, P.R. China.
Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027, China.
Sci Adv. 2020 Apr 17;6(16):eaaz9531. doi: 10.1126/sciadv.aaz9531. eCollection 2020 Apr.
Many load-bearing tissues, such as muscles and cartilages, show high elasticity, toughness, and fast recovery. However, combining these mechanical properties in the same synthetic biomaterials is fundamentally challenging. Here, we show that strong, tough, and fast-recovery hydrogels can be engineered using cross-linkers involving cooperative dynamic interactions. We designed a histidine-rich decapeptide containing two tandem zinc binding motifs. Because of allosteric structural change-induced cooperative binding, this decapeptide had a higher thermodynamic stability, stronger binding strength, and faster binding rate than single binding motifs or isolated ligands. The engineered hybrid network hydrogels containing the peptide-zinc complex exhibit a break stress of ~3.0 MPa, toughness of ~4.0 MJ m, and fast recovery in seconds. We expect that they can function effectively as scaffolds for load-bearing tissue engineering and as building blocks for soft robotics. Our results provide a general route to tune the mechanical and dynamic properties of hydrogels at the molecular level.
许多承重组织，如肌肉和软骨，具有高弹性、韧性和快速恢复能力。然而，在同一合成生物材料中兼具这些力学性能从根本上来说具有挑战性。在此，我们表明，可通过涉及协同动态相互作用的交联剂来设计出强度高、韧性好且能快速恢复的水凝胶。我们设计了一种富含组氨酸的十肽，其含有两个串联的锌结合基序。由于变构结构变化诱导的协同结合，该十肽比单个结合基序或孤立配体具有更高的热力学稳定性、更强的结合强度和更快的结合速率。含有肽 - 锌复合物的工程化混合网络水凝胶表现出约3.0兆帕的断裂应力、约4.0兆焦/立方米的韧性，并能在数秒内快速恢复。我们期望它们能有效地作为承重组织工程的支架以及软机器人的构建模块发挥作用。我们的结果提供了一条在分子水平上调控水凝胶力学和动态性能的通用途径。
