Simpson Querrey Institute, Northwestern University, Chicago, IL 60611, USA.
Applied Physics Graduate Program, Northwestern University, Evanston, IL 60208, USA.
Science. 2018 Nov 16;362(6416):808-813. doi: 10.1126/science.aat6141. Epub 2018 Oct 4.
Soft structures in nature, such as protein assemblies, can organize reversibly into functional and often hierarchical architectures through noncovalent interactions. Molecularly encoding this dynamic capability in synthetic materials has remained an elusive goal. We report on hydrogels of peptide-DNA conjugates and peptides that organize into superstructures of intertwined filaments that disassemble upon the addition of molecules or changes in charge density. Experiments and simulations demonstrate that this response requires large-scale spatial redistribution of molecules directed by strong noncovalent interactions among them. Simulations also suggest that the chemically reversible structures can only occur within a limited range of supramolecular cohesive energies. Storage moduli of the hydrogels change reversibly as superstructures form and disappear, as does the phenotype of neural cells in contact with these materials.
自然界中的软物质结构，如蛋白质组装体，可以通过非共价相互作用可逆地组织成功能性且通常是分层的结构。在合成材料中对这种动态能力进行分子编码仍然是一个难以实现的目标。我们报告了肽-DNA 缀合物和肽的水凝胶，这些水凝胶可以组织成相互交织的纤维的超结构，当添加分子或电荷密度发生变化时会解体。实验和模拟表明，这种响应需要由它们之间的强非共价相互作用指导的分子的大规模空间再分配。模拟还表明，化学可逆结构只能在有限的超分子内聚能范围内发生。水凝胶的储能模量随着超结构的形成和消失而可逆变化，与这些材料接触的神经细胞的表型也是如此。
