Photopolymerizable Imidazolium Methacrylate Networks for Controlled Dexamethasone Release: Potential Application in Uveitis Therapy

This study focuses on the development of photopolymerizable systems using imidazolium methacrylate, a liquid salt made from imidazole and methacrylic acid, cross-linked with either cyclohexanedimethanol dimethacrylate (CDMM) or ethylene glycol dimethacrylate (EGDMA). These systems are specifically designed for the controlled release of dexamethasone in ocular applications. The swelling behavior, mechanical characteristics, drug release kinetics, and biocompatibility of the resulting materials on different cell lines were evaluated. The dexamethasone release process was governed by a combination of diffusion and polymer matrix relaxation, influenced by drug–polymer interactions and temperature. Implants containing higher dexamethasone concentrations exhibited a release mechanism predominantly controlled by polymer relaxation, associated with chain reorganization. The results revealed that the release profiles varied with the cross-linking agent used and showed significant temperature dependence. At average body temperature, increased matrix swelling and faster release rates were observed. It was observed that higher drug concentrations led to greater porosity, thereby promoting faster release. Conversely, cross-linking agents with lower steric hindrance produced denser networks, resulting in reduced release rates. All tested formulations showed good cytocompatibility. These findings highlight the potential of imidazolium methacrylate–based photopolymerizable systems for applications in personalized medical devices, particularly for controlled and/or localized corticosteroid delivery.