Photodynamic tissue destruction

"Photodynamic tissue destruction" refers to the process by which photodynamic therapy (PDT) achieves selective tissue damage. PDT relies on three essential components: a photosensitizing agent (drug), exposure to light of a specific wavelength, and molecular oxygen. The photosensitizer accumulates in the target tissue and is activated by light, generating cytotoxic reactive oxygen species (ROS) including singlet oxygen. These ROS then cause local tissue destruction through direct cell death (apoptosis and necrosis), vascular injury (leading to ischemia of the target area), and by stimulating immune responses against the treated tissue. This process is not attributable to a single molecular target or receptor, but rather is a coordinated biochemical cascade initiated by the physical activation of the photosensitizer and the production of ROS. Examples of photosensitizer drugs for PDT include porfimer sodium, aminolevulinic acid, and verteporfin, among others. PDT is used for localized treatment of various cancers and certain eye disorders, but the specific molecular targets are the cellular and vascular components exposed to ROS, not a discrete molecule or receptor[1][2][3][4][5][9]. Key caveat: "Photodynamic tissue destruction" is not a molecular target as per the conventions of molecular pharmacology or drug discovery, but a therapeutic effect resulting from PDT. Its inclusion as a drug target is therefore incorrect or misleading for content structured at the protein/receptor/gene level.

Other names

Photodynamic therapy-mediated cytotoxicityPhotodynamic tissue ablationPhotodynamic reaction