Characterization of a squaraine/chitosan system for photodynamic therapy of cancer
Autor(a) principal: | |
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Data de Publicação: | 2016 |
Outros Autores: | , , , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10198/13704 |
Resumo: | In this work, a squaraine dye CS5 was characterized and evaluated for its potential in photodynamic therapy. The studies were performed in ethanol and also in a powdered biopolymer, in this case chitosan. Ground state absorption, absolute fluorescence quantum yields, fluorescence lifetimes, and transient absorption were determined in order to evaluate the advantage of adsorbing the dye onto a biopolymer. Several concentrations of the dye, adsorbed onto chitosan, were prepared in order to evaluate the concentration effect on the photophysical parameters under study. A remarkable increase in the fluorescence quantum yield and lifetimes was detected when compared with the dye in solution. Also, a very clear dependence of the fluorescence quantum yield on the concentration range was found. A lifetime distribution analysis of these systems fluorescence evidenced the entrapment of the dye onto the chitosan environment with a monoexponential decay which corresponds to the monomer emission in slightly different environments. The transient absorption spectrum was obtained without sensitization indicating the existence of a triplet state which takes special importance in the generation of phototoxic species namely singlet oxygen. The subcellular localization of a photosensitizer is critical for efficient photoinduced cell death, in this way, colocalization studies were performed within HeLa cell line (human cervical carcinoma) through confocal microscopy. Toxicity in the dark and phototoxicity of CS5 were also evaluated for the same cellular model. |
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Characterization of a squaraine/chitosan system for photodynamic therapy of cancerIn this work, a squaraine dye CS5 was characterized and evaluated for its potential in photodynamic therapy. The studies were performed in ethanol and also in a powdered biopolymer, in this case chitosan. Ground state absorption, absolute fluorescence quantum yields, fluorescence lifetimes, and transient absorption were determined in order to evaluate the advantage of adsorbing the dye onto a biopolymer. Several concentrations of the dye, adsorbed onto chitosan, were prepared in order to evaluate the concentration effect on the photophysical parameters under study. A remarkable increase in the fluorescence quantum yield and lifetimes was detected when compared with the dye in solution. Also, a very clear dependence of the fluorescence quantum yield on the concentration range was found. A lifetime distribution analysis of these systems fluorescence evidenced the entrapment of the dye onto the chitosan environment with a monoexponential decay which corresponds to the monomer emission in slightly different environments. The transient absorption spectrum was obtained without sensitization indicating the existence of a triplet state which takes special importance in the generation of phototoxic species namely singlet oxygen. The subcellular localization of a photosensitizer is critical for efficient photoinduced cell death, in this way, colocalization studies were performed within HeLa cell line (human cervical carcinoma) through confocal microscopy. Toxicity in the dark and phototoxicity of CS5 were also evaluated for the same cellular model.American Chemical SocietyBiblioteca Digital do IPBFerreira, Diana P.Conceição, David S.Fernandes, FátimaSousa, T.Calhelha, Ricardo C.Ferreira, Isabel C.F.R.Santos, Paulo F.Ferreira, L.F. Vieira2017-01-09T16:38:01Z20162016-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10198/13704engFerreira, Diana P.: Conceição, David S.; Fernandes, F.; Sousa, T.; Calhelha, Ricardo C.; Ferreira, Isabel C.F.R.; Santos, Paulo F.; Ferreira, L.F. Vieira (2016). Characterization of a squaraine/chitosan system for photodynamic therapy of cancer. Journal of Physical Chemistry B. ISSN 1520-6106. 120:7, p. 1212-12201520-610610.1021/acs.jpcb.5b11604info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-11-21T10:32:06Zoai:bibliotecadigital.ipb.pt:10198/13704Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T23:03:41.219634Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Characterization of a squaraine/chitosan system for photodynamic therapy of cancer |
title |
Characterization of a squaraine/chitosan system for photodynamic therapy of cancer |
spellingShingle |
Characterization of a squaraine/chitosan system for photodynamic therapy of cancer Ferreira, Diana P. |
title_short |
Characterization of a squaraine/chitosan system for photodynamic therapy of cancer |
title_full |
Characterization of a squaraine/chitosan system for photodynamic therapy of cancer |
title_fullStr |
Characterization of a squaraine/chitosan system for photodynamic therapy of cancer |
title_full_unstemmed |
Characterization of a squaraine/chitosan system for photodynamic therapy of cancer |
title_sort |
Characterization of a squaraine/chitosan system for photodynamic therapy of cancer |
author |
Ferreira, Diana P. |
author_facet |
Ferreira, Diana P. Conceição, David S. Fernandes, Fátima Sousa, T. Calhelha, Ricardo C. Ferreira, Isabel C.F.R. Santos, Paulo F. Ferreira, L.F. Vieira |
author_role |
author |
author2 |
Conceição, David S. Fernandes, Fátima Sousa, T. Calhelha, Ricardo C. Ferreira, Isabel C.F.R. Santos, Paulo F. Ferreira, L.F. Vieira |
author2_role |
author author author author author author author |
dc.contributor.none.fl_str_mv |
Biblioteca Digital do IPB |
dc.contributor.author.fl_str_mv |
Ferreira, Diana P. Conceição, David S. Fernandes, Fátima Sousa, T. Calhelha, Ricardo C. Ferreira, Isabel C.F.R. Santos, Paulo F. Ferreira, L.F. Vieira |
description |
In this work, a squaraine dye CS5 was characterized and evaluated for its potential in photodynamic therapy. The studies were performed in ethanol and also in a powdered biopolymer, in this case chitosan. Ground state absorption, absolute fluorescence quantum yields, fluorescence lifetimes, and transient absorption were determined in order to evaluate the advantage of adsorbing the dye onto a biopolymer. Several concentrations of the dye, adsorbed onto chitosan, were prepared in order to evaluate the concentration effect on the photophysical parameters under study. A remarkable increase in the fluorescence quantum yield and lifetimes was detected when compared with the dye in solution. Also, a very clear dependence of the fluorescence quantum yield on the concentration range was found. A lifetime distribution analysis of these systems fluorescence evidenced the entrapment of the dye onto the chitosan environment with a monoexponential decay which corresponds to the monomer emission in slightly different environments. The transient absorption spectrum was obtained without sensitization indicating the existence of a triplet state which takes special importance in the generation of phototoxic species namely singlet oxygen. The subcellular localization of a photosensitizer is critical for efficient photoinduced cell death, in this way, colocalization studies were performed within HeLa cell line (human cervical carcinoma) through confocal microscopy. Toxicity in the dark and phototoxicity of CS5 were also evaluated for the same cellular model. |
publishDate |
2016 |
dc.date.none.fl_str_mv |
2016 2016-01-01T00:00:00Z 2017-01-09T16:38:01Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10198/13704 |
url |
http://hdl.handle.net/10198/13704 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Ferreira, Diana P.: Conceição, David S.; Fernandes, F.; Sousa, T.; Calhelha, Ricardo C.; Ferreira, Isabel C.F.R.; Santos, Paulo F.; Ferreira, L.F. Vieira (2016). Characterization of a squaraine/chitosan system for photodynamic therapy of cancer. Journal of Physical Chemistry B. ISSN 1520-6106. 120:7, p. 1212-1220 1520-6106 10.1021/acs.jpcb.5b11604 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
American Chemical Society |
publisher.none.fl_str_mv |
American Chemical Society |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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RCAAP |
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RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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