Modulation of Photoluminescence To Detect Glutathione-Responsiveness of Phthalimide-Derived Polymeric Micelles

The delivery of a drug payload to targeted cells using a polymeric vehicle cannot be accurately traced solely by photoluminescence emission. A multicomponent synthetic method is imperative that should integrate fluorescence change observation along with in vitro release of the therapeutic agent. The present work outlines the design, synthesis, spectroscopic characterization, theoretical approaches, GSH-triggered surface morphology observation, and in vitro release of curcumin from a phthalimide-based pPEGMA₂₂-b-pPTHDS₁₆ copolymer micelle. This copolymer has a disulfide bond as a cleavable linker, a phthalimide group as a fluorescent marker, and curcumin as a model cargo. Disulfide cleavage, initiated by interaction with glutathione under physiological conditions, leads to the liberation of free curcumin and a simultaneous red-shift fluorescence emission (λ_max = 530 nm). This promising drug delivery system demonstrates potential for theranostic applications for the targeted therapies, as it seamlessly integrates treatment and real-time imaging of drug absorption at a cellular level.