Microfluidics-Facilitated Synthesis of Methacrylated Chitosan-Coated Liposomes: An Innovative Platform for Prolonged Ocular Retention and Controlled Drug Release

This study presents methacrylated chitosan-coated liposomes (CSMA-liposomes) as an innovative ocular drug delivery technology to tackle the issue of rapid drug removal from the eye. Liposomes synthesized via microfluidic techniques were coated with CSMA to enhance mucoadhesion and prolong residence time through electrostatic and covalent interactions with mucin. Liposomal optimization produced uncoated liposomes measuring 154 nm with a PDI of 0.12, which rose to 208 nm following CSMA coating. The zeta potential shifted from -8.3 to +36 mV, indicating effective functionalization. In vitro, CSMA-liposomes exhibited significant mucoadhesion, resulting in a particle size increase to 369 nm and a zeta potential of +2.4 mV after 4 h of incubation with mucin. Ex vivo retention on bovine conjunctival tissues exhibited enhanced fluorescence retention of CSMA-liposomes relative to untreated and chitosan-coated liposomes. The release of dexamethasone sodium phosphate from CSMA-liposomes demonstrated a sustained, biphasic profile, indicating potential for improved ocular bioavailability and therapeutic effectiveness.