Reactive oxygen species-sensitive drug release

Reactive oxygen species-sensitive drug release is a targeted drug delivery strategy rather than a discrete biological target like a protein or receptor. This approach exploits the significant biochemical gradient of reactive oxygen species (ROS) between healthy tissues and pathological environments such as tumor microenvironments or sites of chronic inflammation. In these diseased states, ROS levels are typically elevated due to mitochondrial dysfunction or activated immune cells, providing a stimulus for 'smart' drug delivery systems. These systems utilize ROS-responsive materials—including polymers containing thioketal or boronic acid ester linkages—to encapsulate therapeutic agents like chemotherapeutics or anti-inflammatory drugs. When the delivery vehicle encounters high ROS concentrations, it undergoes a chemical transformation that triggers the release of the drug, thereby increasing local efficacy while minimizing systemic side effects (PMID: 30605051). While highly promising for precision medicine, challenges remain regarding the precise control of release kinetics and the potential long-term toxicity of the synthetic components used in the carrier's construction (PMID: 28415392).

Other names

ROS-responsive drug delivery systemsOxidative stress-responsive drug releaseROS-triggered drug deliveryROS-sensitive nanocarriersReactive oxygen species-responsive delivery

The mechanism involves the incorporation of ROS-labile functional groups—such as thioketals, aryl boronic esters, thioethers, or proline oligomers—into the backbone or side chains of drug carriers like micelles, hydrogels, or nanoparticles. Upon exposure to high local concentrations of reactive oxygen species (e.g., hydrogen peroxide, superoxide, or hydroxyl radicals), these chemical moieties undergo oxidation, cleavage, or solubility transitions. This biochemical trigger results in the structural disintegration of the carrier or the cleavage of a prodrug linker, leading to the localized release of the therapeutic payload directly at the site of pathology (PMID: 27263050, PMID: 30125492).