Crosslinking Methods in Polysaccharide-Based Hydrogels for Drug Delivery Systems

Polysaccharides are inspiring and valuable molecules to the development of novel drug delivery systems owing to their natural availability, non-toxicity, biocompatibility, good biological performance, and chemical similarity to the physiological environment, besides their noticeable use for tailored-materials assembly. Biodegradable hydrogels based on polysaccharides have been widely studied as potential pharmaceutical forms due to their controlled release properties, which improve drug bioavailability, therapeutic efficacy, and patient compliance. Despite these advantages, polysaccharide materials present insufficient mechanical properties or processability, thus, to overcome these drawbacks, feasible and suitable crosslinking methods are employed to improve polysaccharide hydrogels strength and stability. Therefore, this review presents recent advances in crosslinking methods of polysaccharide hydrogels, including chitosan, cellulose, hyaluronic acid, and alginate, providing examples of manufacturing processes with emphasis in their use as carriers in drug delivery. Polysaccharide-based hydrogels represent a sustainable, biocompatible, and appreciable alternative to obtain novel drug delivery systems.