Ionotropic cross-linking methods for different types of biopolymeric hydrogels

Hydrogels are a kind of water-rich polymer that is chemically or physically cross-linked. Cross-linking is a stabilizing technique used in polymer chemistry that causes a polymeric chain to expand in many dimensions, creating a network structure. One definition of "cross-link" describes a bond between two polymer chains. Both ionic and covalent forms exist. Recent years have seen a rise in the pharmaceutical industry's interest in biopolymers, namely intelligent and active biopolymer systems. With this link in mind, biopolymers including chitosan, gum ghatti, neem gum, cellulose, carrageenan, gelatin, dextran, and others have gathered a lot of interest in recent years. They have substantial functionality in several applications because of their adaptable features, including nontoxicity, biocompatibility, biodegradability, and adaptability. This chapter provides information about the ionotropic cross-linking of chitosan, alginate, and pectin-based hydrogels and their biomedical applications.