Water-soluble cyclodextrin (CyD) complexed with porphyrin derivatives with different substituents in the -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.

The weak absorbance of pristine C , C , and fullerene derivatives at wavelengths over 600 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 C 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 C and C .

Porphyrin derivatives with hydroxyphenyl or dihydroxyphenyl moieties in the meso-position were able to dissolve in water by complexation with two trimethyl-β-cyclodextrins (TMe-β-CDxs) without further chemical modification of pophyrins or addition...

5,15-Diazaporphyrins, which have al arge absorption at wavelengths over 600 nm, were dissolved in water by complexf ormation with b-(1,3-1,6)-d-glucans. Aqueous solutions of these complexes were relativelys table compared with their trimethyl-b-cyclodextrin-complexed analogues. b-Glucan-complexed diazaporphyrins showed quenched fluorescencea nd had low singlet-oxygen-genera-tion abilities owing to random self-aggregation.H owever, external stimuli, such as the presenceo fl iposomes or intracellularu ptake, restored the fluorescence and singletoxygen-generation abilities of b-glucan-complexed diazaporphyrins. Consequently, b-glucan-complexed diazaporphyrins showedv ery high photodynamic activities toward HeLa cells.

Inclusion complexes of 5,15-diazaporphyrin derivatives in trimethyl-β-cyclodextrin exhibited high photodynamic activity under visible-light irradiation at wavelengths greater than 620 nm.