Metal ion crosslinked polysaccharide hydrogels: A review on their potential for therapeutic delivery and tissue...

Natural polysaccharides are extensively used in pharmaceutical and biomedical fields as carriers of diverse therapeutics and in tissue engineering applications. Apart from their biocompatibility and biodegradability, they can be tailored as per the specific requirements of the delivery carriers. Metal ion cross-linking of polysaccharide chains is a major tailoring technique which alters the rheological, mechanical, tensile, and other physicochemical attributes of the polysaccharides. Metal ions interact with the specific functional groups (carboxyl or sulphate) present in the polysaccharide chains to form water insoluble hydrogels, leading to structural stabilization of the polysaccharides. The concentration and valency of the ions dictate the porosity, rigidity, physicochemical, rheological, and mechanical characteristics of the cross-linked polysaccharide chains, paving the way for tailor-made formulations and delivery carriers. The review aims to explore the role of metal ions in the development of polysaccharide-based tailored matrix/medium. The article will provide comprehensive insights on how metal ions alter the swelling, porosity, mechanical, and dissolution properties of the polysaccharide chains. Finally, the review will serve as a groundwork resource providing valuable insights that can guide researchers in the fundamentals of their projects accordingly, such as achieving predetermined outcomes in areas like drug and cell delivery, tissue engineering, etc.