Cellular lipid membranes

Cellular lipid membranes and their associated biomolecules serve as the primary structural targets for photodynamic therapy (PDT) and photoimmunotherapy (PIT). In these therapeutic modalities, photosensitizing agents (such as porphyrins or antibody-dye conjugates) accumulate within the plasma membrane or organelle membranes of tumor cells. Upon exposure to specific wavelengths of light, these agents undergo electronic excitation and transfer energy to molecular oxygen, generating highly reactive oxygen species (ROS) like singlet oxygen (Agostinis et al., 2011, CA: A Cancer Journal for Clinicians). These ROS induce immediate oxidative damage, including lipid peroxidation and the cross-linking of membrane proteins, which compromises the structural integrity of the cell (Castano et al., 2004, Nature Reviews Cancer). This disruption triggers rapid cell death through necrosis, apoptosis, or autophagy, and can also lead to the release of damage-associated molecular patterns (DAMPs) that stimulate an anti-tumor immune response (Kobayashi et al., 2011, Nature Medicine). Because the cytotoxic effect is restricted to the area where both the drug and light are present, this target allows for high spatial precision in treating localized tumors.

Other names

Tumor cell membranesPlasma membranesOrganelle membranesLipid bilayerBiological membranes

Generation of reactive oxygen species (ROS), primarily singlet oxygen, upon light activation of a localized photosensitizer, leading to lipid peroxidation and oxidative damage of membrane-associated proteins.