核酸碱基分子增粘水凝胶体系构筑及机理探讨

Hydrogel is one of important soft and wet materials. In recent years, the mechanical properties of hydrogels have been significantly improved by constructing the network structure and molecular bonding. However, the adhesive properties, as a more important performance of hydrogels in practical applications, have been often ignored. In life, the hydrogen bonding and hydrophobic interaction are responsible for the stabilization of nucleic acid macromolecules. Therefore, we envision that nucleobases can significantly enhance the adhesive properties of hydrogels based on the physical interactions, such as hydrogen bonding, metal-complexation, hydrophobic interaction, π-π stacking and so on. In this project, a novel bio-inspired strategy driven by nucleobases is proposed to achieve an adhesive hydrogel. By means of intermolecular noncovalent interactions, the hydrogel can exhibit excellent adhesion to all material surfaces or organisms. Moreover, the balance of cohesion and adhesion can be regulated though combining with the hydrophobic association, hybrid cross-linked, double-network structure and other factors. Subsequently, the adhesive mechanism of hydrogels driven by nucleobase is elaborated in detail to achieve a new generation of adhesive hydrogel. It would provide an important theoretical foundation and support for the application of hydrogels in would dressings, medical electrodes, wearable devices and so on.

高分子水凝胶是一类重要的软湿材料。近些年，研究人员通过构建体系网络结构及分子键合方式，实现了水凝胶力学行为的显著提升。然而，人们往往忽略了水凝胶材料在实际应用中更为重要的粘结性能。生命体内的碱基通过氢键和疏水堆积作用而使核酸大分子链稳定存在，我们受到启发并大胆提出设想：如果将碱基分子引入水凝胶体系内，将会依靠碱基分子与基体表面可能产生的氢键、金属络合、疏水作用等物理作用力而使水凝胶具有特殊粘性特征。本课题拟提出核酸碱基仿生增粘水凝胶新思路，将碱基分子引入水凝胶体系，通过分子间非共价键作用力，使水凝胶对所有固体材料和生物体组织器官均能够表现出优异的粘性，结合疏水缔合、杂化交联、双网络结构等因素，调控水凝胶体系内聚力和界面粘结力的平衡关系，详细阐释水凝胶材料粘韧机理并实现新一代碱基仿生增粘水凝胶体系构筑，为水凝胶材料在功能敷料、医用电极、可穿戴设备等方面应用提供重要的理论基础和依据。

水凝胶由于其优异的生物相容性以及柔软性被广泛地应用于组织工程、药物缓释、柔性电子等领域。近年来，粘附性水凝胶的设计与开发获得了极大的关注，然而，至今大部分粘附性水凝胶仍然面临力学性能弱、粘附性差、无法实现耐用性粘附性以及湿润环境下的粘合等问题。通过本项目的实施，我们提出了一种碱基增粘策略来设计粘性水凝胶的概念，通过将核酸碱基引入到水凝胶体系中，通过调控单体组成、比例、交联形式（碱基间氢键、疏水缔合、杂化交联）等因素，进一步调控水凝胶体系的粘结力与内聚力的平衡关系，成功赋予水凝胶通用性粘性、高强的粘韧性能、反复性粘性、宽温度范围下的粘附性等优异的功能特性。这种碱基增粘水凝胶对各种固体材料以及生物组织均展示出良好的粘附性能。其粘附机理主要是依靠碱基分子所提供的多重物理粘附作用，包括：疏水作用、氢键作用、金属络合作用、阳离子-π相互作用和/或π-π堆积作用等。进一步，通过对粘韧性能的系列研究，我们深入理解并阐释了界面粘结力与体系内聚力的密切关系及影响因素，并揭示了碱基增粘水凝胶本质机理。这种受生物仿生的碱基增粘水凝胶在伤口敷料、医用电极、组织黏合剂、和可穿戴电子设备等应用具有重要研究意义。在完成本项目的过程中，一共发表了25篇高影响力的SCI研究论文（第一标注）。