RESUMO
The objective of our work was to describe the photophysical properties (absorption and fluorescence) of the sensitizers TPPS4, ZnTPPS4 a PdTPPS4 and above all the complexes of these sensitizers with cyclodextrin carriers HP-alpha-CD, HP-beta-CD and HP-gamma-CD (2-hydroxypropyl-alpha, beta, gamma-cyclodextrin) in a suitable environment for the cultivation of cancerous cell lines, and to determine the optimal radioactive conditions for maximizing photodynamic effects in cancerous cells.
Assuntos
Ciclodextrinas/química , Portadores de Fármacos/química , Fotoquimioterapia , Radiossensibilizantes/química , Neoplasias/tratamento farmacológico , Fotoquímica , Polímeros/química , Porfirinas/química , Pirróis/química , Espectrometria de Fluorescência , EspectrofotometriaRESUMO
Photodynamic therapy of cancer uses the interaction of sensitizers and light to destroy cancer cells. In this study we tested the cellular uptake of meso-tetrakis(4-sulfonatophenyl)porphine (TPPS4) and its complex PdTPPS4 in the presence or absence of 2-hydroxypropyl-cyclodextrins (hpCDs) on G361 human melanoma cells. Self-fluorescence in G361 cells were measured by Perkin-Elmer LS50B luminometer equipped with well plate reader accessory. Morphological changes in cells have been evaluated using inversion fluorescent microscope Olympus IX 70 and image analysis. The uptake of the sensitizer PdTPPS4 at the given time interval from 1 to 48 hours is markedly higher than the uptake of TPPS4. The highest uptake was found for sensitizer PdTPPS4 in combination with hpbetaCD. TPPS4 and PdTPPS4 especially in the supramolecular complex with nontoxic cyclodextrin carriers represent efficient sensitizers for photodynamic therapy in vitro on G361 cells.
Assuntos
Ciclodextrinas/farmacocinética , Portadores de Fármacos/farmacocinética , Melanoma Experimental/metabolismo , Porfirinas/farmacocinética , Radiossensibilizantes/farmacocinética , Neoplasias Cutâneas/metabolismo , Linhagem Celular Tumoral/metabolismo , Humanos , Técnicas In Vitro , Microscopia de Fluorescência , PaládioRESUMO
The aim of this study was analysis of DNA damage in the cell line of the human melanoma G361 after photodynamic therapy (PDT) by comet assay. Photodynamic therapy is based on cytotoxic action of sensitizers (10 microM ZnTPPS4 fixed into 1 mM cyclodextrin hpbetaCD) and light with a suitable wavelength. Single-cell gel electrophoresis (SCGE, comet assay) is a rapid and sensitive method for detecting DNA strand breaks at the level of single cells. Great amount of DNA damage was detected with the dose of irradiation of 0.1; 0.5 J and 2.5 J x cm(-2). Only radiation dose of visible light in the presence of sensitizers can induce DNA breaks of tumour cells. Cells with DNA damage appear as fluorescent comets with tails of DNA fragmentation. In contrast, cells with undamage DNA appear as round spots, because their intact DNA does not migrate out of the cell.
