Photodynamic Activity of Fullerene Derivatives Solubilized in Water by Natural‐Product‐Based Solubilizing Agents

Abstract

Water‐soluble fullerenes prepared using solubilizing agents based on natural products are promising photosensitizers for photodynamic therapy. Cyclodextrin, β‐1,3‐glucan, lysozyme, and liposomes can stably solubilize not only C₆₀ and C₇₀ but also some C₆₀ derivatives in water. To improve the solubilities of fullerenes, specific methods have been developed for each solubilizing agent. Water‐soluble C₆₀ and C₇₀ exhibit photoinduced cytotoxicity under near‐ultraviolet irradiation, but not at wavelengths over 600 nm, which are the appropriate wavelengths for photodynamic therapy. However, dyad complexes of solubilized C₆₀ derivatives combined with light‐harvesting antenna molecules were found to improve photoinduced cytotoxicities at wavelengths over 600 nm. Furthermore, controlling the fullerene and antenna molecule positions within the solubilizing agents was shown to affect photosensitizer performance.