Estudos dos farmacos fotossensiveis ftalocianina cloroaluminio tetrassulfonada e ftalocianina cloroaluminio incorporada a lipossomos
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Data
2008
Autores
Duarte, Janaina [UNIFESP]
Orientadores
Plapler, Hélio [UNIFESP]
Tipo
Tese de doutorado
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Objetivo: Estudar comparativamente as drogas fotossensíveis ftalocianina cloroalumínio tetrassulfonada e ftalocianina cloroalumínio incorporada a lipossomos. Método: A cinética de ambas as drogas foi realizada por meio de espectroscopia de fluorescência ao longo de 48 horas de acompanhamento em tumores colorretais induzidos quimicamente em ratos Wistar. Após esta etapa, animais com o mesmo tipo tumoral induzido, foram tratados com terapia fotodinâmica, associando-se a irradiação com um laser diodo em 660nm e cada um dos elementos fotossensíveis. A análise das amostras foi feita por histomorfometria e imunoistoquímica. Resultados: A cinética mostrou o melhor período de irradiação para cada uma das drogas, sendo este em ambas as drogas entre 22 e 26 horas. Apenas nos grupos da ftalocianina cloroalumínio tetrassulfonada houve necrose decorrente da terapia, sendo observada em maior proporção no grupo 72 horas. A imunoistoquímica realizada com o marcador de proliferação celular Ki67 comprovou os achados da histomorfometria. A ftalocianina cloroalumínio incorporada a lipossomos mostrou-se instável no tecido in vivo, o que pode explicar a não ocorrência do seu efeito. Conclusões: A ftalocianina cloroalumínio tetrassulfonada mostrou-se mais eficiente neste modelo experimental, porém ainda houve a permanência considerável de tecido tumoral no sítio irradiado, o que sugere a terapia fotodinâmica como terapia coadjuvante a outras técnicas convencionais.
Purpose: To compare the photosensitizers chloroaluminum phthalocyanine tetrasulfonate and chloroaluminum phthalocyanine incorporated into liposomes. Methods: The kinetics of both drugs was carried out by fluorescence spectroscopy for 48 hours of monitoring in chemically induced colorectal tumors in Wistar rats. After that, animals with the same tumors induction protocol were treated by photodynamic therapy using in each group a different type of drugs associated with diode laser irradiation at 660nm. Results: The kinetics showed the best period of irradiation for each drug between 22 and 26 hours. Necrosis caused by the therapy has just occurred in chloroaluminum phthalocyanine tetrasulfonate group and the greater areas have occurred in the 72 hours group. The immunohistochemical performed with the cell proliferation marker Ki67 has comproved the findings of histomorphometry. The chloroaluminum phthalocyanine incorporated into liposomes have seemed to be unstable in vivo, which may explain the not occurrence of its purpose. Conclusions: The chloroaluminum phthalocyanine tetrasulfonate proved to be more efficient in this experimental model, even though there was a considerable permanence of tumoral tissue suggesting the photodynamic therapy as a adjuvant therapy to other conventional techniques.
Purpose: To compare the photosensitizers chloroaluminum phthalocyanine tetrasulfonate and chloroaluminum phthalocyanine incorporated into liposomes. Methods: The kinetics of both drugs was carried out by fluorescence spectroscopy for 48 hours of monitoring in chemically induced colorectal tumors in Wistar rats. After that, animals with the same tumors induction protocol were treated by photodynamic therapy using in each group a different type of drugs associated with diode laser irradiation at 660nm. Results: The kinetics showed the best period of irradiation for each drug between 22 and 26 hours. Necrosis caused by the therapy has just occurred in chloroaluminum phthalocyanine tetrasulfonate group and the greater areas have occurred in the 72 hours group. The immunohistochemical performed with the cell proliferation marker Ki67 has comproved the findings of histomorphometry. The chloroaluminum phthalocyanine incorporated into liposomes have seemed to be unstable in vivo, which may explain the not occurrence of its purpose. Conclusions: The chloroaluminum phthalocyanine tetrasulfonate proved to be more efficient in this experimental model, even though there was a considerable permanence of tumoral tissue suggesting the photodynamic therapy as a adjuvant therapy to other conventional techniques.
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São Paulo: [s.n.], 2008. 82 p.