Deoxyribonucleic acid (DNA) stores genetic information as a biomolecule, and also is regarded as a block copolymer and polyanion. Under favorable environments, DNA polymeric chains can spontaneously self-assemble into well-defined secondary or even higher ordered structures by following Watson-Crick base-paring rules, thus making DNA a competitive alternative in the fabrication of materials with precisely designed molecular structure and tailored functions. Among DNA based materials, DNA hydrogels comprising three-dimensional networks of DNA polymeric chains, have received considerable attention as a new class of polymeric materials particularly as biomaterials, showing great potential in a wide range of promising applications. Targeting to a specific application, DNA chain composed of four deoxyribonucleotide monomers (abbreviated as A, T, C and G) can be designed rationally and synthesized precisely, thus endowing a hydrogel with desirable functions and properties, such as responsiveness upon pH, enzyme, ions and biomolecules. Moreover, other functional materials may be introduced into DNA hydrogels, yielding multi-functional hybrid hydrogels. This review highlights recent progress on DNA hydrogels from a polymeric perspective, including general molecular design principles, synthesis strategies, and applications. DNA hydrogels are categorized according to the structure of building blocks including linear DNA, dendritic DNA and hybrid. The development roadmap of DNA hydrogels is sketched chronologically. Landmark work on the preparation of DNA hydrogels are presented to illustrate the design principles and synthesis strategy. The mechanical property and structure relationship is detailed to illuminate the mechanical regulation principle. Representative applications in biosensing, therapeutics, protein production, cell culture, intelligent device, and environmental protection are exemplified to show how DNA hydrogels are rationally and exquisitely designed to address application issues. The challenges and future development of DNA hydrogels are discussed at the end of the review.

脱氧核糖核酸（DNA）将遗传信息存储为生物分子，也被视为嵌段共聚物和聚阴离子。在有利的环境下，DNA聚合链可以遵循Watson-Crick基本配制规则自发地自组装成定义明确的二级或什至更高序的结构，从而使DNA成为具有精确设计的分子结构和量身定制的材料制造中的竞争选择功能。在基于DNA的材料中，包含DNA聚合链的三维网络的DNA水凝胶作为一类新型的聚合材料特别是作为生物材料已受到相当大的关注，在广泛的有希望的应用中显示出巨大的潜力。针对特定应用，DNA链由四个脱氧核糖核苷酸单体（缩写为A，T，C和G）可以合理设计和精确合成，从而赋予水凝胶以所需的功能和特性，例如对pH，酶，离子和生物分子的响应性。而且，可以将其他功能材料引入DNA水凝胶中，从而产生多功能杂合水凝胶。这篇综述从聚合物的角度突出了DNA水凝胶的最新进展，包括一般的分子设计原理，合成策略和应用。DNA水凝胶根据结构单元的结构进行分类，这些结构单元包括线性DNA，树突状DNA和杂合体。DNA水凝胶的发展路线图是按时间顺序绘制的。介绍了具有里程碑意义的DNA水凝胶的制备工作，以说明设计原理和合成策略。详细的机械性能和结构关系阐明了机械调节原理。以生物传感，治疗，蛋白质生产，细胞培养，智能设备和环境保护等方面的代表性应用为例，展示了如何合理合理地设计DNA水凝胶以解决应用问题。在评论的结尾讨论了DNA水凝胶的挑战和未来的发展。