Chitosan-Based Hydrogels

Hydrogels are cross-linked polymeric networks that can retain a moisture environment and mimic human soft tissues. Chitosan, a linear polysaccharide with pH-responsive self-assembling properties, is an attractive candidate for hydrogel construction owing to the existence of intrinsic intermolecular and intramolecular hydrogen bonds and versatile reactive amino groups. Recently, a variety of chitosan-based hydrogels have been developed via diverse approaches, which could be generally categorized as multilayered hydrogels, hydrogels based on alkali/urea solvent system, injectable hydrogels, self-healing hydrogels, shape memory hydrogels, and superabsorbent hydrogels. Following a brief introduction of the chitosan hydrogels, this chapter introduces recent advances in chitosan-based hydrogels with emphasis on their preparation, characterization, properties, and possible applications. In addition, current challenges and future perspectives in this field are also discussed to suggest a new developing direction.