Visible-light-induced annihilation of tumor cells with platinum-porphyrin conjugates.
Despite the extensive use of porphyrins in photodynamic therapy (PDT), tetraplatinated porphyrins have so far not been studied for their anticancer properties. Herein, we report the synthesis of such novel platinum-porphyrin conjugates as well as their photophysical characterization and in vitro light-induced anticancer properties. These conjugates showed only minor cytotoxicity in the dark, but IC50 values down to 19 nM upon irradiation with light at 420 nm.These values correspond to an excellent phototoxic index (PI=IC50 in the dark/IC50 in light), which reached 5000 in a cisplatin-resistant cell line. After incubation with HeLa cells, nuclear Pt concentrations were 30 times higher than with cisplatin. All of these favorable characteristics imply that tetraplatinated porphyrin complexes are worthy of exploration as novel PDT anticancer agents in vivo.
Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zürich (Switzerland).
Anu
A
Naik
Riccardo
R
Rubbiani
Gilles
G
Gasser
Bernhard
B
Spingler
D000970:Antineoplastic Agents / Q000737:chemistry / Q000633:toxicity; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002945:Cisplatin / Q000737:chemistry / Q000633:toxicity; D006367:HeLa Cells; D006801:Humans; D008027:Light; D017319:Photosensitizing Agents / Q000737:chemistry* / Q000633:toxicity; D010984:Platinum / Q000737:chemistry*; D011166:Porphyrins / Q000737:chemistry*
D000970:Antineoplastic Agents; D017319:Photosensitizing Agents; D011166:Porphyrins; D010984:Platinum; D002945:Cisplatin
cancer therapy; photodynamic therapy; platinum; porphyrinoids; red light