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Structure and biodistribution relationships of photodynamic sensitizers

TitleStructure and biodistribution relationships of photodynamic sensitizers
Publication TypeJournal Article
Year of Publication1996
AuthorsBoyle, RW, Dolphin, D
JournalPhotochemistry and Photobiology
Volume64
Pagination469-485
Date PublishedSep
Type of ArticleReview
ISBN Number0031-8655
KeywordsCHLORIN-E6, HUMAN-MALIGNANT TUMOR, IN-VIVO FLUORESCENCE, L-ASPARTYL, LASER SCANNING, LIPOSOME-DELIVERED SI(IV)-NAPHTHALOCYANINE, microscopy, MOUSE-TUMOR MODEL, PHOTOSENSITIZING PROPERTIES, RING-A BPD, SULFONATED ALUMINUM PHTHALOCYANINES, TISSUE DISTRIBUTION
Abstract

Photodynamic therapy (PDT) has, during the last quarter century, developed into a fully fledged biomedical field with its own association, the International Photodynamic Association (TPA) and regular conferences devoted solely to this topic, Recent approval of the first PDT sensitizer, Photofrin(R) (porfiner sodium), by health boards in Canada, Japan, the Netherlands and United States for use against certain types of solid tumors represents, perhaps, the single most significant indicator of the progress of PDT from a laboratory research concept to clinical reality. The approval of Photofrin(R) will undoubtedly encourage the accelerated development of second-generation photosensitizers, which have recently been the subject of intense study, Many of these second-generation drugs show significant differences, when compared to Photofrin(R), in terms of treatment times postinjection, light doses and drug doses required for optimal results, These differences can ultimately be attributed to variations in either the quantum efficiency of the photosensitizer in situ, which is in turn affected by aggregation state, localized concentration of endogenous quenchers and primary photophysics of the dye, or the intratumoral and intracellular localization of the photosensitizer at the time of activation with light, The purpose of this review is to bring together data relating to the biodistribution and pharmacokinetics of second-generation sensitizers and attempt to correlate this with structural and electronic features of these molecules, As this requires a clear knowledge of photosensitizer structure, only chemically well-characterized compounds are included, e,g. Photofrin(R) and crude sulfonated phthalocyanines have been excluded as they are known to be complex mixtures, Nonporphyrin-based photosensitizers, e,g, rose bengal and the hypericins, have also been omitted to allow meaningful comparisons to be made between different compounds, As the intracellular distribution of photosensitizers to organelles and other subcellular structures can have a large effect on PDT efficacy, a section will be devoted to this topic.

URL<Go to ISI>://A1996VG53300012