title: Photodynamic evaluation of tetracarboxy-phthalocyanines in model systems.
abstract: The present work reports the synthesis, photophysical and photochemical characterization and photodynamic evaluation of zinc, aluminum and metal free-base tetracarboxy-phthalocyanines (ZnPc, AlPc and FbPc, respectively). To evaluate the possible application of phthalocyanines as a potential photosensitizer the photophysical and photochemical characterization were performed using aqueous (phosphate-buffered solution, PBS) and organic (dimethyl sulfoxide, DMSO) solvents. The relative lipophilicity of the compounds was estimated by the octanol-water partition coefficient and the photodynamic activity evaluated through the photooxidation of a protein and photohemolysis. The photooxidation rate constants (k) were obtained and the hemolytic potential was evaluated by the maximum percentage of hemolysis achieved (Hmax) and the time (t50) to reach 50% of the Hmax. Although these phthalocyanines are all hydrophilic and possess very low affinity for membranes (log PO/W=-2.0), they led to significant photooxidation of bovine serum albumin (BSA) and photohemolysis. Our results show that ZnPc was the most efficient photosensitizer, followed by AlPc and FbPc; this order is the same as the order of the triplet and singlet oxygen quantum yields (ZnPc>AlPc>FbPc). Furthermore, together, the triplet, fluorescence and singlet oxygen quantum yields of zinc tetracarboxy-phthalocyanines suggest their potential for use in theranostic applications, which simultaneously combines photodiagnosis and phototherapy.
authors.affiliation: Instituto de Física, Universidade Federal de Goiás (UFG), 74001-970 Goiânia, GO, Brazil.
authors.forename: Lais
authors.initials: L
authors.lastname: Alonso
authors.affiliation: Department of Chemistry, The University of North Carolina at Chapel Hill, Murray Hall 2202B, Chapel Hill, NC 27599-3290, United States.
authors.forename: Renato N
authors.initials: RN
authors.lastname: Sampaio
authors.affiliation: Center for Natural Sciences and Humanities, Federal University of ABC (UFABC), Avenida dos Estados, 5001, Bloco B, Santo André, SP, Brazil.
authors.forename: Thalita F M
authors.initials: TF
authors.lastname: Souza
authors.affiliation: Instituto de Química, Universidade Federal de Goiás (UFG), 74001-970 Goiânia, GO, Brazil.
authors.forename: Rodrigo C
authors.initials: RC
authors.lastname: Silva
authors.affiliation: Instituto de Ciências Exatas e Naturais, Universidade Federal do Pará, P.O. Box 479, 66075-110 Belém, PA, Brazil.
authors.forename: Newton M Barbosa
authors.initials: NM
authors.lastname: Neto
authors.affiliation: Center for Natural Sciences and Humanities, Federal University of ABC (UFABC), Avenida dos Estados, 5001, Bloco B, Santo André, SP, Brazil.
authors.forename: Anderson O
authors.initials: AO
authors.lastname: Ribeiro
authors.affiliation: Instituto de Física, Universidade Federal de Goiás (UFG), 74001-970 Goiânia, GO, Brazil.
authors.forename: Antonio
authors.initials: A
authors.lastname: Alonso
authors.affiliation: Instituto de Física, Universidade Federal de Goiás (UFG), 74001-970 Goiânia, GO, Brazil; Instituto de Química, Universidade Federal de Goiás (UFG), 74001-970 Goiânia, GO, Brazil. Electronic address: pablo@ufg.br.
authors.forename: Pablo J
authors.initials: PJ
authors.lastname: Gonçalves
mesh_terms: D000818:Animals; D002417:Cattle; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D004910:Erythrocyte Membrane / Q000737:chemistry; D006461:Hemolysis / Q000528:radiation effects; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D007211:Indoles / Q000737:chemistry* / Q000494:pharmacology; D054833:Isoindoles; D008027:Light; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000737:chemistry / Q000494:pharmacology; D010084:Oxidation-Reduction; D010782:Photolysis / Q000187:drug effects / Q000528:radiation effects; D017319:Photosensitizing Agents / Q000737:chemistry* / Q000494:pharmacology; D012710:Serum Albumin, Bovine / Q000737:chemistry; D026082:Singlet Oxygen / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D014867:Water / Q000737:chemistry; D017967:Zinc Compounds
chemical_list: D007211:Indoles; D054833:Isoindoles; D009942:Organometallic Compounds; D017319:Photosensitizing Agents; D017967:Zinc Compounds; D014867:Water; C052159:Zn(II)-phthalocyanine; D026082:Singlet Oxygen; D012710:Serum Albumin, Bovine; C060570:aluminum phthalocyanine; C013647:phthalocyanine; D004121:Dimethyl Sulfoxide