photodynamic action

Photodynamic action refers to the process in **photodynamic therapy (PDT)** wherein a photosensitizing compound, when activated by light of a defined wavelength in the presence of tissue oxygen, generates reactive oxygen species (primarily singlet oxygen)[1][2][4][6][7]. These reactive species cause localized cell death via oxidative damage to vital cellular components. PDT is used for treating various cancers, dermatological conditions, infections, and some ocular diseases. The process is not a single molecular target, but rather a synergy of light, photosensitizer, and oxygen leading to selective cytotoxicity in target tissues. The effectiveness and safety profile depend on the photosensitizer used, light delivery, and oxygen availability.

Other names

Photodynamic reactionPDT mechanismPhototoxic actionPhotochemical action

Activation of a photosensitizer by light of a specific wavelength in the presence of oxygen, leading to the generation of cytotoxic reactive oxygen species (singlet oxygen and free radicals) that damage and kill target cells