卡拉胶是一类广泛分布于红藻中的生物高分子物质。商业卡拉胶一直以来被用于食品产品中的乳化剂、稳定剂、增稠剂和凝胶剂。卡拉胶被视为具有改变疾病和微生物共生活性的生物活性多糖。卡拉胶作为生物相容性功能材料，目前被越来越广泛地用于制造水凝胶和纳米结构，包括碳点、纳米颗粒和纳米纤维等。在这篇综述中，我们将描述卡拉胶的独特结构特性及其功能关联。我们总结了卡拉胶的重要物理化学特性，包括粘附剂和剪切变稀性。并讨论了卡拉胶作为抗病毒和抗肿瘤药物以及功能材料在临床试验中的最新结果。我们还强调了利用卡拉胶基于各种药物制剂开发靶向药物输送系统的最新进展，以及卡拉胶作为三维打印生物墨水材料在组织工程和再生医学中的应用。最后，我们展望了卡拉胶在临床实践中作为多功能材料商业化的主要障碍和挑战。这篇文章对卡拉胶的结构特征、独特流变性质和生物功能关系的综合评价，将为其在生物医学应用潜力方面提供新的洞见。版权所有©2023 Elsevier B.V.出版。

Carrageenans are a group of biopolymers widely found in red seaweeds. Commercial carrageenans have been traditionally used as emulsifiers, stabilizers, and thickening and gelling agents in food products. Carrageenans are regarded as bioactive polysaccharides with disease-modifying and microbiota-modulating activities. Novel biomedical applications of carrageenans as biocompatible functional materials for fabricating hydrogels and nanostructures, including carbon dots, nanoparticles, and nanofibers, have been increasingly exploited. In this review, we describe the unique structural characteristics of carrageenans and their functional relevance. We summarize salient physicochemical features, including thixotropic and shear-thinning properties, of carrageenans. Recent results from clinical trials in which carrageenans were applied as both antiviral and antitumor agents and functional materials are discussed. We also highlight the most recent advances in the development of carrageenan-based targeted drug delivery systems with various pharmaceutical formulations. Promising applications of carrageenans as a bioink material for 3D printing in tissue engineering and regenerative medicine are systematically evaluated. We envisage some key hurdles and challenges in the commercialization of carrageenans as a versatile material for clinical practice. This comprehensive review of the intimate relationships among the structural features, unique rheological properties, and biofunctionality of carrageenans will provide novel insights into their biomedicine application potential.Copyright © 2023. Published by Elsevier B.V.