Antibody Targeted Photolysis.

The technique of Antibody Targeted Photolysis (ATPL) is reviewed from an historical perspective with a summary of the literature since the first experiments were performed in 1983. Attention is given to both the biological and photophysical properties of the various immunoconjugates that have been developed. References to critical discoveries and competing technologies in the photodynamic literature are given. Topics include: synthesis of immunoconjugates, in vitro vs. in vivo toxicity, in vivo biodistribution, immunoconjugate delivery, photosensitizer selection based on photophysical properties, light delivery for specific applications, oxygen requirements, and other physicochemical phenomena. A mathematical model of the dynamics for cell killing based upon the transport of phototoxins to the cell surface is developed. A generalized set of coupled differential equations is given, which conveniently summarizes the manifold requirements stressed earlier for successful cell killing. Solutions are then presented for an idealized set of conditions appropriate for an isolated tumor cell. Suggestions for further improvements and follow-up experiments are made that could help in the evolution of ATPL into a useful clinical therapy and/or probe for cell biological studies.