Targeted Photodynamic Therapy with a Folate/Sensitizer Assembly Produced from Mesoporous Silica

A mesoporous silica material prepared by using folic acid (FA) as a template enables the effective encapsulation of meso-tetrakis(4-carboxyphenyl)porphyrin (TCPP) in its interior. Combination of steady-state and time-resolved absorption and emission spectroscopy demonstrate that FA and TCPP are released from the silica material to the aqueous phase in the form of a non-covalent assembly. This assembly does not form by simple mixing of the two components in the absence of silica, suggesting the key role of the material in the assembling process. The FA/TCPP assembly exhibits dual color fluorescence in the visible region, good photosensitization capability of singlet oxygen, and enhanced photo-induced mortality in KB cancer cells overexpressing folate receptor, if compared with the free components.