Chitosan-Coated Liposomes: Advances in Synthesis, Modification and Biomedical Applications

Chitosan-coated liposomes (CLPs) have emerged as a multifunctional drug delivery platform that effectively overcomes the key limitations of conventional liposomes, including poor stability, rapid in vivo clearance, weak mucoadhesion, and insufficient targeting specificity. The natural cationic nature of chitosan enables stable coating onto negatively charged liposome surfaces via electrostatic interactions, forming a stable core–shell structure that significantly improves liposomal stability, prolongs circulation time, and enhances mucoadhesive ability. The abundant reactive groups on the chitosan backbone allow further conjugation of targeting ligands, polyethylene glycol chains, and stimuli-responsive moieties, thereby endowing the delivery system with active targeting, long-circulating, and smart drug release properties. Various coating strategies, such as electrostatic deposition, layer-by-layer self-assembly, ionic crosslinking, and microfluidic in-situ coating, provide flexibility and precise controllability for formulation design. These systems have demonstrated considerable therapeutic potential across multiple administration routes, as well as in anti-infective, tumor-targeted, and immunomodulatory applications, by improving drug retention, enabling controlled release, and enhancing bioavailability. Therefore, this review summarizes the synthesis methods, modification strategies, and biomedical applications of CLPs, with the aim of providing a reference for future development in this field.