Sternberg, E. and David Dolphin
Curr. Med. Chem.
A review, with 179 references. There are three major classes of photosensitizers which can initiate a phototoxic effect to tissues upon irradiation. These are the cationic dyes (Type I Photosensitizer), the psoralens (Type I and II Photosensitizer), and cyclic polypyrrolic compds. (Type II Photosensitizer). The polypyrrolic compdounds such as porphyrins have been investigated since the late 1800's for their ability to destroy tissue. In the last ten years, compdounds such as chlorins and expanded porphyrins have begun to dominate the preclinical field because they can be activated with light at wavelengths tissue does not effectively absorb. The results of these investigation have been reported in more than 10,000 papers in the field covering aspects from mechanisms of action, photophysics, structure activity relationships, new compd. development and clin. investigations. With the approval of PHOTOFRIN, (porfimer sodium), the first of the pyrrolic compound to win acceptance by international regulatory bodies and with nearly 10 other second generation compounds undergoing early clinical trials for diseases ranging from esophageal and skin cancers to age related macular degeneration, the field of photodynamic therapy would seem to have a bright future.