Organic dye

Organic dyes are a diverse category of carbon-based molecules capable of absorbing and emitting light, extensively utilized in medical practice as diagnostic contrast agents and therapeutic photosensitizers [2, 10, 24]. Clinically significant dyes such as indocyanine green and fluorescein are used for fluorescence-guided surgery, angiography, and the assessment of organ function, while others like methylene blue are employed to treat methemoglobinemia and vasoplegia [4, 15, 21]. In therapeutic contexts, these dyes can serve as active agents in photodynamic therapy (PDT) and photothermal therapy (PTT) by generating reactive oxygen species or localized heat upon light activation to destroy malignant cells or pathogens [2, 21, 22]. Although organic dyes are not biological targets themselves, they are frequently conjugated to targeting ligands like antibodies to localize to specific receptors or are selectively uptaken by transporters such as organic anion transporting polypeptides (OATP) [1, 6, 15]. Safety considerations include the risk of hypersensitivity and anaphylaxis, photosensitivity, and specific drug-drug interactions, such as the potential for serotonin syndrome associated with methylene blue's inhibition of monoamine oxidase A [4, 21].

Other names

FluorophoreChromophoreSynthetic dyePhotosensitizerOptical contrast agent

Organic dyes primarily function as diagnostic and therapeutic agents through their optical properties, absorbing light and emitting fluorescence for imaging or generating reactive oxygen species (ROS) and heat for phototherapy [2, 21, 22]. Certain dyes also exert specific pharmacological effects, such as methylene blue's inhibition of monoamine oxidase A (MAO-A) and nitric oxide synthase (NOS) [12, 21].