Alginate Gels: Review of Chemistry and Recent Advances in Applications

Alginate, a natural polysaccharide extracted from brown seaweed, has long been used to form firm hydrogels when crosslinked with divalent ions. This has garnered much attention because of the highly favorable properties of alginate, which is renewable, biodegradable, and biocompatible. This review explores the fundamentals and chemistry of alginate hydrogels, in addition to the recent advancements in the applications of these hydrogels and their composites to address current issues, namely medical applications, water reclamation, and agriculture. In medicine, these hydrogels have recently been applied in wound dressings, drug delivery, and tissue engineering. The natural complexation of di- and trivalent ions makes alginate hydrogels highly applicable for the adsorption of heavy metal ions, phosphates, and certain dyes. Finally, recent advances in agricultural applications include soil fortification (with water, nutrients, and pesticides), pH buffering, and seed coating. These advancements are also tabulated for ease of consumption, and current research gaps and future directions are discussed.