Cellular membranes and local molecular oxygen

Cellular membranes and local molecular oxygen refers to the biophysical environment where molecular oxygen partitions into the lipid bilayer of cells. Oxygen is significantly more soluble in the hydrophobic core of biological membranes than in the surrounding aqueous environment, creating a localized concentration gradient [1]. This environment is not a traditional molecular target like a receptor or enzyme, but it is the primary site of action for photodynamic therapy (PDT) and certain radiotherapies [2]. In these treatments, photosensitizing drugs or ionizing radiation interact with the local oxygen within the membrane to produce singlet oxygen and other reactive oxygen species (ROS) [2]. These ROS induce lipid peroxidation, which compromises membrane integrity and triggers apoptotic or necrotic cell death [3]. Consequently, the availability of local molecular oxygen within the membrane is a limiting factor for the efficacy of these clinical interventions, particularly in hypoxic tumor microenvironments [1, 2].

Other names

Membrane oxygenationIntramembrane oxygenLipid-phase oxygen

Facilitates the production of singlet oxygen and other reactive oxygen species (ROS) upon activation of photosensitizers or ionizing radiation, leading to membrane damage.