New photosensitizers for photodynamic therapy: combined effect of metallopurpurin derivatives and light on transplantable bladder tumors.
A series of metallopurpurins was tested for their photodynamic activity against transplantable N-[4-(5-nitro-2-furyl)-2-thiazoyl]formamide-induced urothelial tumors growing in male Fischer CDF (F344/CrlBR) rats. Histological examination of tumors in animals treated with the metallopurpurins and red light (greater than 590 nm, 360 J/cm2) revealed tumor necrosis 24 h after completion of therapy. Control tumors showed no histological change. In 30-day tumor regrowth studies, 70% of animals treated with the metallopurpurin derivative SnET2 were free of tumors while 50% of the animals treated with the free-base purpurin ET2 were free of tumor. Metallopurpurins have intense absorptions in the red region of the visible spectrum, a region with good tissue penetration. The metallopurpurins are easily prepared from the corresponding purpurins with a high degree of purity. This study demonstrates the potential of these photosensitizers for photodynamic cancer therapy.
Morgan
A R
AR
Department of Chemistry, University of Toledo, Ohio 43606.
Garbo
G M
GM
Keck
R W
RW
Selman
S H
SH
D000818:Animals; D008297:Male; D008670:Metals; D009368:Neoplasm Transplantation; D010778:Photochemotherapy; D011166:Porphyrins / Q000627:therapeutic use*; D051381:Rats; D011916:Rats, Inbred F344; D001749:Urinary Bladder Neoplasms / Q000188:drug therapy* / Q000473:pathology
D008670:Metals; D011166:Porphyrins