ABSTRACT
The usefulness of many drugs in therapeutic, diagnostic, and preventive medicine is limited by their lack of selectivity for the target site. The drug-targeting concept is based on the use of macromolecular carrier systems to deliver drugs to the intended area of action, and the basic assumption is that carriers have an inherent or acquired ability to interact selectively with their targets. The rationale for the use of macromolecular carrier systems for photosensitizers (PS) delivery is similar to that discussed for delivery of chemotherapeutics and toxins. Typical motivations for the use of conjugates in photodynamic therapy are increased concentrations of the PS may be achieved at target sites; and nontumor-localizing PS with efficient photochemistry may be used, thereby providing a greater repertoire of usable PS. Although the studies using monoclonal antibodies–PS conjugates appear to be promising, they are all somewhat preliminary.
