Introduction to Redox-Responsive Delivery Systems

A redox-responsive drug delivery system (DDS) releases medications based on oxidation-reduction (redox) level variations, enabling targeted drug release with minimal side effects. Cancer remains a major threat, and chemotherapy is the most effective treatment. Redox-sensitive DDSs emphasize high glutathione (GSH) levels in tumor cells, although normal cells also contain GSH at lower concentrations. Also, redox-responsive DDSs to enhance drug control and reduce adverse effects. These DDSs rely on chemical entities like disulfide and diselenide bonds, and succinimide-thioether linkages to respond to redox changes. Nanocarriers improve drug solubility, making anticancer therapies more effective. Tumor microenvironments are acidic pH, high reactive oxygen species (ROS), and redox potential gradients. These factors influence redox-responsive DDSs, which regulate immune responses by interacting with reactive oxygen and nitrogen species. Redox reactions can cause cytocidal effects. Imbalances in reactive oxygen species and reactive nitrogen species (ROS & RNS) levels causes’ chronic immune activation, underlying diseases like infections, allergies, autoimmune disorders, neurodegenerative conditions, and cancer. Anticancer drugs, often hydrophobic, face challenges like low solubility and off-target toxicity. Redox-responsive nanoparticles (NPs) enhance drug delivery by increasing solubility and localizing treatment. Overall, DDSs optimize drug release location, timing, and dosage, improving therapeutic efficacy and minimizing side effects.