ABSTRACT
Anionic and neutral fullerene derivatives were dissolved in water by using ß-(1,3-1,6)-d-glucan (ß-1,3-glucan) as a solubilizing agent. In the water-solubilized complexes, the concentrations of fullerene derivatives were ≈0.30â mm and the average particle sizes were ≈90â nm. The ß-1,3-glucan-complexed fullerene derivative with a carboxylic acid was found to have higher photodynamic activity toward macrophages under visible-light irradiation (λ>610â nm) than other ß-1,3-glucan-complexed fullerene derivatives. This result suggests that carboxylic acid moieties in the complex enhance the binding affinity with ß-1,3-glucan receptors on the surface of macrophages when the ß-1,3-glucan is recognized. In contrast, all ß-1,3-glucan-complexed fullerene derivatives showed no photodynamic activity toward HeLa cells under the same conditions.
Subject(s)
Fullerenes/pharmacology , Macrophages/drug effects , Photochemotherapy , Water/chemistry , beta-Glucans/pharmacology , Animals , Dose-Response Relationship, Drug , Fullerenes/chemistry , HeLa Cells , Humans , Mice , Molecular Structure , Particle Size , RAW 264.7 Cells , Solubility , Structure-Activity Relationship , Surface Properties , beta-Glucans/chemistryABSTRACT
We have evaluated the photodynamic activities of C60 derivative·Î³-cyclodextrin (γ-CDx) complexes and demonstrated that they were significantly higher than those of the pristine C60 and C70·Î³-CDx complexes under photoirradiation at long wavelengths (610-720 nm), which represent the optimal wavelengths for photodynamic therapy (PDT). In particular, the cationic C60 derivative·Î³-CDx complex had the highest photodynamic ability because the complex possessed the ability to generate high levels of (1)O2 and provided a higher level of intracellular uptake. The photodynamic activity of this complex was greater than that of photofrin, which is the most widely used of the known clinical photosensitizers. These findings therefore provide a significant level of information toward the optimization of molecular design strategies for the synthesis of fullerene derivatives for PDT.
ABSTRACT
X-Ray crystallography revealed that the C(60) derivative·Î³-cyclodextrin (γ-CDx) complex has a pseudorotaxane structure and the structure of the crystal clarified the importance of multi-point hydrogen bonds between two γ-CDxs for stabilising the 3·Î³-CDx complex.