An insight into chemically modified chitosan and their biological, pharmaceutical, and medical applications: A review

Quaternized chitosan derivatives demonstrated improved antimicrobial activity. Carboxy chitosan derivatives, resulting from carboxylation with glyoxylic acid or chloroalkanoic acid, enhance solubility and are utilized in wound healing and antitumor therapies. Modifications like acylation of chitosan alter hydrophobicity, affecting biocompatibility and drug delivery efficiency. Thiolated chitosan derivatives, with enhanced mucoadhesive properties, are advantageous for mucosal drug delivery. Sulfated chitosan derivatives mimic heparin's functions, showcasing anticoagulant, anti-sclerosis, and antiviral properties. Phosphorylated chitosan derivatives find utility in orthopedics due to their cation-exchange abilities. Heterocyclic chitosan derivatives exhibit antibacterial properties, while Schiff's base and epoxy Schiff's base chitosan derivatives display antimicrobial enhancements and improved drug delivery profiles. Aminosalicylhydrazide cross-linked Schiff's base chitosan derivatives exhibit versatility with heightened antimicrobial and biological activities. Continually exploring novel functional groups highlights the importance of staying current with ongoing research in chitosan modification. Future research should focus on developing innovative chitosan derivatives with enhanced bioactivity, physicochemical properties, and multifunctional capabilities to improve pharmaceutical applications. Additionally, studies on scalability, commercialization, and eco-friendly production methods are essential to ensure industrial viability and sustainability.