RESUMO
Porphyrin derivatives with hydroxyphenyl or dihydroxyphenyl moieties in the meso-position were able to dissolve in water by complexation with two trimethyl-ß-cyclodextrins (TMe-ß-CDxs) without further chemical modification of porphyrins or addition of dimethyl sulfoxide as a co-solvent. TMe-ß-CDx-complexed tetra(hydroxyphenyl)porphyrins (THPPs) with phenols in meso-positions have a much higher photodynamic activity than TMe-ß-CDx-complexed tetrakis(dihydroxyphenyl)porphyrins (TDHPPs) with dihydroxyphenyl in the meso-position. The main reason for the different photoactivity is due to the intracellular uptakes of these complexes. Thus phenols in meso-positions of porphyrin derivatives in the complexes were recognized by HeLa cell receptors. Furthermore, the photodynamic activity of TMe-ß-CDx-complexed THPP was much higher than that of THPP injected as a dimethyl sulfoxide solution.
Assuntos
PorfirinasRESUMO
Water-soluble inclusion complexes of 5,15-diazaporphyrin derivatives in the cavities of two trimethyl-ß-cyclodextrins (TMe-ß-CDxs) were synthesised. In the 2 : 1 complexes, two aryl groups of the diazaporphyrins protruded from the upper rims of two TMe-ß-CDxs. The complexes displayed high photodynamic activity under photoirradiation at wavelengths longer than 620 nm. Although the substituents on the two aryl groups protruding from TMe-ß-CDx barely affected intracellular uptake by HeLa cells, the cellular uptake of these complexes was as high as that of a TMe-ß-CDx-tetra(4-hydroxyphenyl)porphyrin complex. Furthermore, the diazaporphyrins in the complexes with TMe-ß-CDxs were able to generate high levels of singlet oxygen because of their strong absorption of light with wavelengths greater than 620 nm.
RESUMO
The weak absorbance of pristine C60 , C70 , and fullerene derivatives at wavelengths over 600â nm hampers the use of these molecules as photosensitizers (PSs) for photodynamic therapy (PDT). The coexistence of light-harvesting antenna molecules with a fullerene derivative in lipid membrane bilayers solved this issue. By controlling the location of the C60 derivative in the lipid membrane, the liposomal dyad system for PDT improved the photodynamic activity via an efficient photoenergy transfer from antenna molecules to the fullerene derivative. The photodynamic activity was found to be much higher than those of dyad systems using pristine C60 and C70 .
Assuntos
Fulerenos/química , Bicamadas Lipídicas/química , Lipossomos/química , Fármacos Fotossensibilizantes , FotoquimioterapiaRESUMO
5,15-Diazaporphyrins, which have a large absorption at wavelengths over 600â nm, were dissolved in water by complex formation with ß-(1,3-1,6)-d-glucans. Aqueous solutions of these complexes were relatively stable compared with their trimethyl-ß-cyclodextrin-complexed analogues. ß-Glucan-complexed diazaporphyrins showed quenched fluorescence and had low singlet-oxygen-generation abilities owing to random self-aggregation. However, external stimuli, such as the presence of liposomes or intracellular uptake, restored the fluorescence and singlet-oxygen-generation abilities of ß-glucan-complexed diazaporphyrins. Consequently, ß-glucan-complexed diazaporphyrins showed very high photodynamic activities toward HeLa cells.
RESUMO
Water-soluble cyclodextrin (CyD) complexed with porphyrin derivatives with different substituents in the meso-positions showed different photodynamic activities toward cancer cells under illumination at wavelengths over 600 nm, the most suitable wavelengths for photodynamic therapy (PDT). In particular, aniline- and phenol-substituted derivatives had high photodynamic activity because of the efficient intracellular uptake of the complexes by tumor cells. These complexes showed greater photodynamic activity than photofrin, currently the main drug in clinical use as a photosensitizer. These results represent a significant step toward the optimization of porphyrin derivatives as photosensitizers.