Institute for Molecules and Materials, Radboud University , Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
Biomacromolecules. 2017 Oct 9;18(10):3310-3317. doi: 10.1021/acs.biomac.7b00964. Epub 2017 Sep 28.
One of the most intriguing and important aspects of biological supramolecular materials is its ability to adapt macroscopic properties in response to environmental cues for controlling cellular processes. Recently, bulk matrix stiffness, in particular, stress sensitivity, has been established as a key mechanical cue in cellular function and development. However, stress-stiffening capacity and the ability to control and exploit this key characteristic is relatively new to the field of biomimetic materials. In this work, DNA-responsive hydrogels, composed of semiflexible PIC polymers equipped with DNA cross-linkers, were engineered to create mimics of natural biopolymer networks that capture these essential elastic properties and can be controlled by external stimuli. We show that the elastic properties are governed by the molecular structure of the cross-linker, which can be readily varied providing access to a broad range of highly tunable soft hydrogels with diverse stress-stiffening regimes. By using cross-linkers based on DNA nanoswitches, responsive to pH or ligands, internal control elements of mechanical properties are implemented that allow for dynamic control of elastic properties with high specificity. The work broadens the current knowledge necessary for the development of user defined biomimetic materials with stress stiffening capacity.
生物超分子材料最有趣和最重要的特点之一是能够根据环境线索自适应宏观性质，从而控制细胞过程。最近，基质的整体硬度，特别是压力敏感性，已被确定为细胞功能和发育的关键力学线索。然而，压力硬化能力以及控制和利用这一关键特性的能力在仿生材料领域相对较新。在这项工作中，DNA 响应水凝胶由配备 DNA 交联剂的半刚性 PIC 聚合物组成，旨在模拟天然生物聚合物网络，这些网络具有这些必需的弹性特性，并且可以通过外部刺激进行控制。我们表明，弹性特性由交联剂的分子结构决定，交联剂的分子结构可以很容易地改变，从而获得具有广泛可调谐软凝胶的高弹性，具有不同的压力硬化状态。通过使用基于 DNA 纳米开关的交联剂来响应 pH 值或配体，可以实现对机械性能的内部控制元件，从而实现高特异性的弹性特性的动态控制。这项工作拓宽了发展具有压力硬化能力的用户定义仿生材料所需的现有知识。
