Aggregation susceptibility on phototransformation of hematoporphyrin derivatives

Autor: Priscila Fernanda Campos de Menezes, Hidetake Imasato, Juliana Carvalho Ferreira, Claudio Sibata, Janice Rodrigues Perussi, V. S. Bagnato
Rok vydání: 2007
Předmět:
Zdroj: Laser Physics Letters. 5:227-235
ISSN: 1612-202X
1612-2011
DOI: 10.1002/lapl.200710111
Popis: Photosensitizers used in PDT suffer degradation by light. In this work, photobleaching of Photogem® (PG), Photofrin® (PF), and Photosan® (PS), hematoporphyrin derivatives, were induced by light in the presence or absence of 1% Triton X-100. The degradation efficiency in the absence of 1% Triton X-100 follows the sequence: PF > PG > PS, which means that PF presented a greater degradation than PG and PS. However, in the presence of the surfactant the degradation efficiency is different: PG ≅ PS > PF. Besides aggregation susceptibility, studies in cell culture (tumor and non tumor cells) and in animals (depth of necrosis) were performed, trying to correlate the stability of these photosensitizers with their photodynamic effect. The results suggest that PF presents higher light induced photocytotoxicity than PG and PS for both types of cells. For the depth of necrosis studies, more aggregated photosensitizer showed a longer time to accumulate in liver (30 min for PG, 120 h for PF, and 720 h for PS). Then, to establish an ideal dosimetry in PDT, one must consider the intrinsic physical chemistry characteristics of the photosensitizer as well as their ability to undergo photobleaching.
Databáze: OpenAIRE
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