A review of sodium alginate-based hydrogels: Structure, mechanisms, applications, and perspectives

With the global emphasis on green and sustainable development, sodium alginate-based hydrogels (SAHs), as a renewable and biocompatible environmental material, have garnered widespread attention for their research and application. This review summarizes the latest advancements in the study of SAHs, thoroughly discussing their structural characteristics, formation mechanisms, and current applications in various fields, as well as prospects for future development. Initially, the chemical structure of SA and the network structure of hydrogels are introduced, and the impact of factors such as molecular weight, crosslinking density, and environmental conditions on the hydrogel structure is explored. Subsequently, the formation mechanisms of SAHs, including physical and chemical crosslinking, are detailed. Furthermore, a systematic review of the applications of SAHs in tissue engineering, drug delivery, medical dressings, wastewater treatment, strain sensor, and food science is provided. Finally, future research directions for SAHs are outlined. This work not only offers researchers a comprehensive framework for the study of SAHs but also provides significant theoretical and experimental foundations for the development of new hydrogel materials.