氢键与疏水聚集协同作用构建高强韧不溶胀可注射水凝胶研究

Injectable hydrogels are attractive biomaterials for many biomedical applications because they can be applied to target sites via minimally invasive delivery and by filling irregular defects in vivo. However, most injectable hydrogels suffer from poor mechanical performance and swell easily, which limit their use and development for practical applications. This project will focus on gaining difunctional block copolymers with adjustable structure and intensity of hydrophobic association, which results from the synergistic interaction between hydrophobic interaction and hydrogen bonding by introducing multiple hydrogen bonds on the chains. The effect of the intensity between chains on the copolymer morphology will be systematically studied to achieve the controlled structure, size, and dispersion state of the copolymer aggregation. Meanwhile, it will be investigated the effect of copolymers aggregation on the microstructure, mechanical and swelling properties of injectable hydrogel in detail. Finally, the relationship between microstructure, mechanical and swelling properties will be discovered by comprehensively investigating the copolymers, and the results will provide guideline for designing and synthesizing tough and non-swellable injectable hydrogels.

可注射水凝胶由于能微创注射至目标部位，并易于充满不规则形状的缺损部位，因而是生物医用领域研究的热点和重点。然而目前可注射水凝胶的力学性能差且易溶胀，严重限制了水凝胶的应用和发展。本项目拟通过在疏水链段中引入多重氢键，获得疏水聚集和氢键协同作用、疏水聚集区结构和强度可调控的双官能线性嵌段共聚物；通过研究多重氢键的引入和链段间作用强度的变化对嵌段共聚物凝聚态的影响，实现凝聚态结构、尺寸及分散状态的可控调节；研究共聚物凝聚态变化对水凝胶微结构、力学性能和溶胀性能的影响规律并揭示其作用机理，建立微结构与水凝胶力学和溶胀性能之间的关系，为设计高强韧不溶胀的可注射水凝胶提供新的指导思路。

可注射水凝胶具有微创注射的优点，在生物医用领域获得了广泛的关注与研究。然而目前可注射水凝胶力学性能差且易溶胀，严重限制了其在体内的应用与发展。本项目通过设计合成疏水链段中含有成四重氢键单元的双官能线性嵌段共聚物，获得了疏水聚集与氢键协同作用的胶束交联剂，研究了四重氢键的引入和疏水聚集区的强度对胶束交联剂尺寸和分散状态的影响，揭示了嵌段共聚物凝聚态变化对水凝胶微结构、力学性能和溶胀性能的影响规律。研究结果表明，四重氢键的引入可有效增强嵌段共聚物的自组装能力与胶束稳定性，适当强的疏水聚集有利于形成稳定且分散均匀的胶束交联剂，弱和过强的疏水聚集分别会导致胶束不稳定和共聚物不溶解。在胶束物理交联水凝胶中，分散均匀的强胶束交联点一方面有效抑制网络中分子链的伸展，赋予水凝胶不溶胀，另一方面强胶束的可形变性及网络的均匀性有效减少应力集中，赋予水凝胶高强韧性。本项目的研究结果为设计制备高强韧不溶胀可注射水凝胶提供了新思路，为建立水凝胶微结构与宏观力学性能之间的关系提供了实验基础和理论指导。