Nanocomposite (NC) hydrogels are promising biomaterials that possess versatile properties and functions for biomedical applications such as drug delivery, biosensor development, imaging and tissue engineering. Different strategies and chemistries have been utilized to define the structure and properties of NC hydrogels. In this review, we discuss NC hydrogels synthesized using dynamic bonds, including dynamic covalent bonds (e.g., Schiff base and boronate ester bond) and non-covalent bonds (e.g., hydrogen bonds and metal-ligand coordination). Dynamic bonds can reversibly break and reform to provide self-healing properties to NC hydrogels as well as be influenced by external factors to allow NC hydrogels with stimulus-responsiveness. The presence of dynamic bonds in NC hydrogels can occur at the polymer-polymer or polymer-particle interfaces, which also determines whether the particles act as fillers or crosslinkers in hydrogels. Several representative examples of NC hydrogels fabricated using dynamic bonds are discussed here, focusing on their design, preparation, properties, applications and future prospects.

Statement of significance

This review provides an overview of the current progress in NC hydrogel development using dynamic bonds, summarizing the material design, fabrication approaches, unique performance and promising biomedical applications. The presence of both nanoparticles and dynamic bonds in hydrogels shows a combined or synergistic effect to provide hydrogels with dynamic features, definable properties, multi-functionality and stimulus-responsiveness for advanced applications. We believe that this review will be of interest to the hydrogel community and inspire researchers to develop next-generation hydrogels.

中文翻译：

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使用动态键设计纳米复合水凝胶

纳米复合 (NC) 水凝胶是一种很有前途的生物材料，具有多种特性和功能，可用于生物医学应用，如药物输送、生物传感器开发、成像和组织工程。已使用不同的策略和化学方法来定义 NC 水凝胶的结构和性质。在这篇综述中，我们讨论了使用动态键合成的 NC 水凝胶，包括动态共价键（例如，席夫碱和硼酸酯键）和非共价键（例如，氢键和金属配体配位）。动态键可以可逆地断裂和重新形成，为 NC 水凝胶提供自愈特性，并受外部因素的影响，使 NC 水凝胶具有刺激响应性。NC 水凝胶中动态键的存在可以发生在聚合物-聚合物或聚合物-颗粒界面上，这也决定了颗粒在水凝胶中是作为填料还是交联剂。这里讨论了几个使用动态键制造的 NC 水凝胶的代表性例子，重点是它们的设计、制备、性能、应用和未来前景。

重要性陈述

本综述概述了使用动态键开发 NC 水凝胶的当前进展，总结了材料设计、制造方法、独特的性能和有前景的生物医学应用。水凝胶中纳米颗粒和动态键的存在显示出一种组合或协同效应，为水凝胶提供了动态特征、可定义的特性、多功能性和刺激响应性，适用于高级应用。我们相信这篇综述会引起水凝胶界的兴趣，并激励研究人员开发下一代水凝胶。