Abstract

Photodynamic therapy is largely an experimental modality for the treatment of a variety of neoplastic and non-neoplastic diseases. It involves the localization of a photoactivatable chemical (photosensitizer) followed by activation with appropriate energy radiation. This photoactivation leads to the generation of active molecular species which are ultimately toxic to biologic substrates (cells and tissues) that encounter them. Due to high absorption of wavelengths >600 nm by endogenous molecules, clinically useful photosensitizers are typically required to absorb at wavelengths >600 nm. Vigorous areas of investigation relevant to photodynamic therapy include design, synthesis and optimal delivery of photosensitizers, mechanisms(both biological and chemical) of phototoxicity and development of light delivery and dosimetry techniques in vivo. The current status and challenges in the field of photodynamic therapy will be discussed in this overview.

© 1995 Optical Society of America