Univ. Grenoble Alpes, Centre de Recherches sur les Macromolécules Végétales (CERMAV)-CNRS, 601, rue de la Chimie, BP 53, 38041 Grenoble Cedex 9, France.
Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, 71 avenue des Martyrs, 38044 Grenoble Cedex 9, France.
Soft Matter. 2020 Apr 15;16(15):3628-3641. doi: 10.1039/d0sm00178c.
Dynamic covalent hydrogels crosslinked by boronate ester bonds are promising materials for biomedical applications. However, little is known about the impact of the crosslink structure on the mechanical behaviour of the resulting network. Herein, we provide a mechanistic study on boronate ester crosslinking upon mixing hyaluronic acid (HA) backbones modified, on the one hand, with two different arylboronic acids, and on the other hand, with three different saccharide units. Combining rheology, NMR and computational analysis, we demonstrate that carefully selecting the arylboronic-polyol couple allows for tuning the thermodynamics and molecular exchange kinetics of the boronate ester bond, thereby controlling the rheological properties of the gel. In particular, we report the formation of "strong" gels (i.e. featuring slow relaxation dynamics) through the formation of original complex structures (tridentate or bidentate complexes). These findings offer new prospects for the rational design of hydrogel scaffolds with tailored mechanical response.
由硼酸酯键交联的动态共价水凝胶是一种很有前途的生物医学应用材料。然而，对于交联结构对所得网络机械性能的影响知之甚少。在此，我们通过混合经两种不同芳基硼酸和三种不同糖单元修饰的透明质酸 (HA) 骨架，对硼酸酯交联进行了机理研究。通过流变学、NMR 和计算分析相结合，我们证明了通过仔细选择芳基硼酸-多元醇对，可以调节硼酸酯键的热力学和分子交换动力学，从而控制凝胶的流变性能。特别地，我们报告了通过形成原始的复杂结构（三齿或二齿配合物）形成“强”凝胶（即具有缓慢弛豫动力学的凝胶）。这些发现为具有定制机械响应的水凝胶支架的合理设计提供了新的前景。
