Antimicrobial Application of Chitosan Derivatives and their Nanocomposites.

Chitosan is derived from chitin polysaccharide, the main component of crustacean shells. Chitosan is a biocompatible, nontoxic, and biodegradable polymer soluble in acidic solutions. It is widely used in the medical and pharmaceutical fields. Antimicrobial activities of chitosan against different bacterial, fungal, and viral pathogens have been considered one of its attractive properties, making chitosan valuable for biological applications, including textile, food, tissue engineering, agriculture, and environmental protection. Additionally, chitosan has beneficial effects on livestock, poultry, fish, and crustaceans, which can enhance immunity, improve feed conversion, and promote growth. However, the water solubility of chitosan influences antimicrobial capabilities, limiting its application. In the present work, we reviewed the preparation, factors affecting antimicrobial activity, morphological structure, antimicrobial mechanism, and application of chitosan derivatives, and the problems and prospects were pointed out. Collectively, this review provided an update on the application of chitosan derivatives and their potential for further advanced applications in the antimicrobial field.