Knoff David S, Szczublewski Haley, Altamirano Dallas, Cortes Kareen A Fajardo, Kim Minkyu
Department of Biomedical Engineering, University of Arizona, Tucson, AZ 85721.
Department of Materials Science and Engineering, University of Arizona, Tucson, AZ 85721.
Macromolecules. 2020 May 12;53(9):3464-3471. doi: 10.1021/acs.macromol.0c00514. Epub 2020 Apr 29.
Reducing topological network defects to enhance elasticity in polymeric materials remains a grand challenge. Efforts to control network topology, primarily focused on crosslinking junctions, continue to underperform compared to theoretical estimations from idealized networks using affine and phantom network theories. Here, artificial protein technology was adapted for the design of polymer-network hydrogels with precisely defined coil-like and rod-like strands to observe the impact of strand rigidity on the mechanical properties of polymeric materials. Cytoskeleton-inspired polymer-network hydrogels incorporated with rod-like protein strands nearly tripled the gel shear elastic modulus and relaxation time compared to coil-like protein strands, indicating an enhanced effective crosslinking density. Furthermore, asymmetric rod-coil protein designs in network strands with an optimal rod:coil ratio improved the hydrogel relaxation time, enhancing the stability of physical macromolecular associations by modulating crosslinker mobility. The careful design of strand rigidity presents a new direction to reduce topological defects for optimizing polymeric materials.
减少拓扑网络缺陷以增强聚合物材料的弹性仍然是一个巨大的挑战。控制网络拓扑的努力主要集中在交联节点上，与使用仿射和虚拟网络理论的理想化网络的理论估计相比，其性能仍然欠佳。在这里，人工蛋白质技术被应用于设计具有精确界定的线圈状和棒状链的聚合物网络水凝胶，以观察链刚性对聚合物材料力学性能的影响。与线圈状蛋白质链相比，掺入棒状蛋白质链的受细胞骨架启发的聚合物网络水凝胶的凝胶剪切弹性模量和弛豫时间几乎增加了两倍，表明有效交联密度有所提高。此外，网络链中具有最佳棒：线圈比例的不对称棒 - 线圈蛋白质设计改善了水凝胶的弛豫时间，通过调节交联剂迁移率提高了物理大分子缔合的稳定性。仔细设计链刚性为减少拓扑缺陷以优化聚合物材料提供了一个新方向。
