Hydrogels prepared from natural polymers have captured extensive attention over the past decades because of their exceptional biocompatibility and nontoxicity, ease of gelation, and functionalization. Thus, natural polymer hydrogels are considered as promising biomaterials that show great potential in the biomedical field. In drug-delivery systems, the extent and the rate with which the drugs reach their targets are highly carrier-dependent, so the demand for intelligent drug-delivery systems is gradually increasing. Recently, natural polymer hydrogels functionalized with magnetic materials have been used as a novel smart response device for drug delivery because of the quick response and remote controllability. This review aims to give the latest advances of magnetic hydrogels based on natural polymers such as polysaccharide, protein, and DNA in drug-delivery systems. Specifically, the first part compares several general synthesis strategies of magnetic natural polymer hydrogels. The applications of magnetic natural polymer hydrogels are described in the second part. For the last part, an overview of the application in drug delivery for the magnetic hydrogels constructed from several representative natural polymers is presented.

中文翻译：

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磁性天然聚合物构建的水凝胶作为药物输送载体的综述。

在过去的几十年中，由天然聚合物制备的水凝胶因其出色的生物相容性和无毒性，易于凝胶化和功能化而备受关注。因此，天然聚合物水凝胶被认为是有前途的生物材料，在生物医学领域显示出巨大的潜力。在药物输送系统中，药物达到目标的程度和速率高度依赖于载体，因此对智能药物输送系统的需求逐渐增加。近来，由于具有快速响应和远程可控性，用磁性材料功能化的天然聚合物水凝胶已被用作新型智能药物输送装置。这篇评论旨在介绍基于天然聚合物（例如多糖，蛋白质，以及药物输送系统中的DNA。具体而言，第一部分比较了磁性天然聚合物水凝胶的几种通用合成策略。磁性天然聚合物水凝胶的应用在第二部分中进行了描述。最后一部分，概述了由几种代表性天然聚合物构成的磁性水凝胶在药物递送中的应用。