Chitosan-Based Nanogels in Modern Drug Delivery: Focus on Protein and Gene Applications

Nanogels have attracted significant attention in recent years due to their high biocompatibility, controlled release capacity, sensitivity to environmental stimuli, and targeted transport characteristics as drug delivery systems. Chitosan, a natural polysaccharide, is a biopolymer widely used in nanogel formulations due to its positively charged structure, biodegradability, and modifiable functional groups. In this review, the therapeutic applications of chitosan-based nanogels are discussed thoroughly, especially emphasizing in the areas of protein/peptide, antigen, and gene transport. Production methods, chemical modification strategies, transport mechanisms to target cells, and the biological activities of these systems have been evaluated. Chitosan nanogels are promising carrier systems in wide range of areas, including gene therapy, immunotherapy, and the delivery of biological agents, owing to their significant characteristics such as intracellular targeting, endosomal escape, and sustained release. Further studies might enable the translation of these systems into clinical applications.