Landscape of carrageenan-based (Nano)materials: Structures, functions and applications with a focus on biomedical uses

Abstract

Carrageenans (CAR) are marine sulfated polysaccharides widely used as texturizing agents in the cosmetic and food industries due to their unique stability and gel-forming properties. Beyond these traditional uses, their rheological features and high charge density have driven their increasing integration as macromolecular matrix components of hydrogels (HG) and nanocomposites (NC). More recently, CAR have also attracted growing attention as functional constituents of nanoparticle (NP) formulations. After summarizing CAR structure and families, extraction strategies, chemical modification and depolymerization processes as well as their physicochemical properties and bioactivities, this review provides a comprehensive and critical overview of 353 articles on CAR-based (nano)materials, including organic NP, hybrid NP, NC, HG, and nanogels. The diversity of architectures, the CAR families employed, the synthesis routes (including chemical modifications and modes of CAR incorporation) and the resulting functional roles within these systems are systematically examined, with particular emphasis on biomedical applications and genuine CAR-based NP platforms. Building on this landscape, future directions and perspectives are outlined to guide the rational development of CAR-based (nano)materials with enhanced functional performance, biomedical relevance and industrial translation potential.