“…Chitosan is commonly found in the outer protective shells of invertebrates and possesses good biocompatibility, biodegradability, nontoxicity, and various physiological functions such as antibacterial, hypocholesterolemic, anticancer, and immune enhancement properties . Chitosan itself is used in many fields, such as beauty care, cosmetics, antimicrobial agents, medical fibers, medical dressings, artificial tissue materials, drug slow-release materials, gene transfer carriers, biomedical fields, medical absorbable materials, tissue engineering carrier materials, medical treatment, and drug development. − Chitosan can form hydrogels by changing pH and temperature and can be degraded in vivo by lysozyme and diacetyl chitosanase, thus forming gels that can be applied in living organisms. Chitosan-based hydrogels have been widely used in controlled drug release, artificial tissues, cartilage repair, medical coatings, and tumor therapy. − …”