RESUMO
A FRET donor-acceptor xanthene-coumarin conjugate has been designed for redox-regulated synergic treatment of photodynamic therapy and chemotherapy with real-time monitoring. The "locked" FRET pair was selectively "unlocked" by biological reducing thiols via rupture of a sacrificial disulfide linker. A distinct change in fluorescence color and selective cancer cell toxicity were observed in vitro.
Assuntos
Clorambucila/análogos & derivados , Clorambucila/farmacologia , Pró-Fármacos/farmacologia , Umbeliferonas/farmacologia , Xantenos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Antineoplásicos/efeitos da radiação , Clorambucila/síntese química , Clorambucila/efeitos da radiação , Terapia Combinada/métodos , Tratamento Farmacológico/métodos , Fluorescência , Glutationa/química , Células HEK293 , Células HeLa , Humanos , Luz , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/efeitos da radiação , Pró-Fármacos/síntese química , Pró-Fármacos/efeitos da radiação , Oxigênio Singlete/química , Nanomedicina Teranóstica , Umbeliferonas/síntese química , Umbeliferonas/efeitos da radiação , Xantenos/síntese química , Xantenos/efeitos da radiaçãoRESUMO
The effects of oxygen in the photolysis of rose bengal, eosin, erythrosin and methylene blue were studied in the presence of formate and electron donors, such as ascorbic acid, aromatic amino acids or aliphatic amines, e.g. triethylamine (TEA). The overall reaction is conversion of oxygen via the hydroperoxyl/superoxide ion radical into hydrogen peroxide. The quantum yield of oxygen uptake (Phi(-O2)) increases with the donor concentration. The photoinduced formation of H2O2 is initiated by quenching of the triplet state of the dye by the donor and subsequent reactions of both the dye and donor radicals with oxygen. For methylene blue and the xanthene dyes in the presence of 10 mM ascorbic acid or 0.1 M TEA Phi(-O2)=0.07-0.25. The spectral and kinetic properties of the specific dye transients, including the radicals involved and the pH and concentration dependences, are discussed.
Assuntos
Aminoácidos Aromáticos/química , Ácido Ascórbico/química , Etilaminas/química , Azul de Metileno/química , Oxigênio/química , Xantenos/química , Ar , Aminoácidos Aromáticos/efeitos da radiação , Ácido Ascórbico/efeitos da radiação , Corantes/química , Corantes/efeitos da radiação , Elétrons , Etilaminas/efeitos da radiação , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Luz , Azul de Metileno/efeitos da radiação , Estrutura Molecular , Oxigênio/efeitos da radiação , Peróxidos/química , Fotólise , Teoria Quântica , Soluções/química , Superóxidos/química , Água/química , Xantenos/efeitos da radiaçãoRESUMO
The trafficking of 2,3,4,5,6-pentafluorodihydrotetramethylrosamine (PF-H(2)TMRos, also known as RedoxSensor Red), a new fluorogenic indicator for oxidative activity, was evaluated in a contact-inhibited cell line, normal rat kidney fibroblast (NRK-49F), using quantitative fluorescence microscopy. After cells were incubated with 1-5 microM dye at 37 degrees C for 10 to 30 min, fluorescent staining of its oxidized product (PF-TMRos) distributed in mitochondria and/or lysosomes. This distribution pattern varied depending on the proliferation state of cells. In proliferating cells, PF-H(2)TMRos was internalized through a nonendocytic pathway, then oxidized in the cytosol, followed by immediate targeting to active mitochondria, resulting in fluorescent staining in this organelle. Photo-oxidation experiments demonstrated that PF-H(2)TMRos is not directly transported to mitochondria. On the contrary, in contact-inhibited cells whose proliferation is inhibited, PF-H(2)TMRos enters cells and is transported to lysosomes before it is oxidized. This results in lysosomal rather than mitochondrial staining. In both proliferating and quiescent cell states, subcellular distribution of the oxidized dye PF-TMRos can be altered by treatment with an oxidant (hydrogen peroxide) or an antioxidant (N-acetyl-L-cysteine), indicating a regulatory relationship between cell proliferation and oxidative activity. In solution assay, this probe can be oxidized by a broad spectrum of oxidizing species including horseradish peroxidase, hydrogen peroxide and horseradish peroxidase, cytochrome c, cytochrome c and hydrogen peroxide, superoxide and hydrogen peroxide, nitric oxide (or nitrite), peroxynitrite, and lipid hydroperoxide. Based on its subcellular distribution and its oxidation by a broad range of oxidizing species, PF-H(2)TMRos is demonstrated to be a novel indicator for cellular oxidative stresses.
Assuntos
Fibroblastos/metabolismo , Corantes Fluorescentes/metabolismo , Estresse Oxidativo , Xantenos/metabolismo , Animais , Transporte Biológico , Divisão Celular , Inibição de Contato , Fibroblastos/ultraestrutura , Corantes Fluorescentes/efeitos da radiação , Peróxido de Hidrogênio/farmacologia , Luz , Lisossomos/metabolismo , Potenciais da Membrana , Microscopia de Fluorescência , Mitocôndrias/metabolismo , Estrutura Molecular , Oxidantes/farmacologia , Oxirredução , Fotoquímica , Ratos , Espectrometria de Fluorescência , Frações Subcelulares , Xantenos/efeitos da radiaçãoRESUMO
The acute toxicity of photodecomposed products of Erythrosine, Eosine, Phloxine and Rose Bengale were studied, since it was found that toxicity of these dyes to fish increased after the dyes had been photoirradiated. Photodecomposed products of the dyes were isolated and identified with UV, IR, NMR spectra and the acute toxicity of those compounds were determined by TLm test. As results of these studies, it became clear that the toxicity of photodecomposed organic products (dehalogenated compounds of dyes) were lower than the mother compounds. The increases in toxicity of the xanthene dyes by photo-irradiation were attributed to the liberated halogens by irradiation.
Assuntos
Corantes/toxicidade , Peixes/fisiologia , Xantenos/toxicidade , Animais , Corantes/análise , Corantes/efeitos da radiação , Fotoquímica , Fatores de Tempo , Xantenos/análise , Xantenos/efeitos da radiaçãoRESUMO
Twenty kinds of coal-tar dyes were subjected to median tolerance limit (TLm) test by use of Himedaka (Oryzias latipes) for the comparision of their acute toxicities. It became clear that 4 kinds of halogens substituted xanthene compounds dyes showed strong acute toxicities. From the fact that uranine had the lower acute toxicity than halogens substituted compounds and the toxicities of these 4 dyes increased through irradiation, it was assumed that halogen atoms in dyes might be responsible for these strong acute toxicities to fish.