ABSTRACT
Photodynamic therapy (PDT) is a treatment modality that combines a light-activatable drug (photosensitizer), activated by light typically in the red or near infrared (NIR) range and ambient oxygen (Agostinis et al., 2011). In the presence of oxygen, photosensitizers are activated by light, which results in the generation of reactive oxygen species (ROS) and consequent biological eects via ROS-mediated oxidative stress. With a sucient amount of photosensitizer, light and oxygen, PDT is able to induce a rapid and ecient cell death, particularly apoptosis, in a variety of cell lines. Because of its eectiveness in inducing cell death, PDT has been approved for the treatment of dierent types of cancers, precancers, and noncancer diseases (e.g., agerelated macular degeneration [AMD], port-wine stain [PWS] birthmarks) where cell proliferation is abnormally activated (Agostinis et al., 2011).
