MORPHOLOGICAL-STUDY OF THE COMBINED EFFECT OF PURPURIN DERIVATIVES AND LIGHT ON TRANSPLANTABLE RAT BLADDER-TUMORS

Abstract

Purpurin derivatives, a group of synthetic photosensitizers, were tested for their photodynaimc activity against transplantable N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide-induced urothetial tumors growing in male Fischer 344 rats. Histological examination of tumors in animals treated with the purpurin derivative and red light (> 590 nm, 360 joules/cm2) revealed tumor cell necrosis 24 h after completion of therapy. Control tumors showed no histological change. Purpurins have a major absorption peak in the red region (>650 nm) of the visible spectrum, a region with good tissue penetration, and purpurins can be synthesized with a high degree of purity. This study demonstrate the potential of purpurin derivatives as photosensitizers for photodynamic cancer therapy.