Chitosan conjugates in precision medicine: from synthesis to their role in advanced drug delivery

Chitosan, owing to its unique characteristics and excellent safety profile, has gained a lot of attention in the development of novel drug delivery systems over the past few decades. The inherent properties of chitosan can be modified and finely tuned to enhance its functionality and targeting abilities. This comprehensive review emphasizes the synthesis pathways of various polymer-chitosan and drug-chitosan conjugates, detailing their mechanisms, critical aspects, and characterization techniques. Furthermore, the role of these conjugates in advanced drug delivery, including improved solubility, stability, active targeting capabilities in various diseases, including cancer, along with enhanced mucoadhesive properties and drug release kinetics in response to certain stimuli (stimuli-responsive drug delivery systems) have also been addressed. Finally, the translational challenges and future outlook of these conjugates in the development of safe, effective, and target-specific precision medicines are briefly discussed.