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Chelation with Metal is not Essential for Antitumor Photodynamic Activity of Sulfonated Phthalocyanines † ¶
Author(s) -
Feofanov Alexei,
Grichine Alexei,
Karmakova Tatyana,
Kazachkitalia,
Pecherskih Elena,
Yakubovskaya Raisa,
Luḱyanets Eugene,
Derkacheva Valentina,
EgretCharlier Marguerite,
Vigny Paul
Publication year - 2002
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1562/0031-8655(2002)0750527cwmine2.0.co2
Subject(s) - chelation , photodynamic therapy , metal , chemistry , combinatorial chemistry , phthalocyanine , inorganic chemistry , organic chemistry
It is generally assumed that a central metal is essential for the efficiency of phthalocyanines in photodynamic therapy (PDT) of cancer. Contrary to the set opinion, the results of the present study indicate that the metal‐free sulfonated phthalocyanines (H 2 PcS n , where n is the number of sulfonate groups per molecule) possess a considerable photoactivity. The relative phototoxicities of H 2 PcS 1.5 , H 2 PcS 2.4 , H 2 PcS 3.1 and H 2 PcS 3.8 on HEp2 human epidermoid carcinoma cells were 3.3, 20, 3.3 and 1, respectively, thus demonstrating dependence of the activity on the sulfonation degree, known for metallo‐PcS n . A significant delay in tumor growth and a decrease in tumor regrowth rate were observed in mice after PDT with H 2 PcS 2.4 . The antitumor effect declined in the order H 2 PcS 2.4 > H 2 PcS 3.1 > H 2 PcS 1.5 and vanished for H 2 PcS 3.8 . We demonstrate here that the high photodynamic activity of H 2 PcS 2.4 can be explained by its physicochemical properties in living cells and tissues. Thus, H 2 PcS n (n is about 2) can be considered as a new alternative in PDT of light‐accessible neoplasms and further clinic‐oriented studies are warranted.