Redox-responsive supramolecular amphiphiles constructed via host-guest interactions for photodynamic therapy

A supramolecular photosensitizer delivery system has been established through the self-assembly of supramolecular amphiphiles constructed by the host-guest interaction between poly(ethylene glycol)-beta-cyclodextrin (PEG-beta-CD) and adamantane-terminated porphyrin derivatives bearing a disulfide bond (TPPC6-SS-Ada). TPPC6-SS-Ada/PEG-beta-CD supramolecular amphiphiles can self-assemble into spherical micelles in water, and the assembled morphology was respectively characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). Intracellular uptake and localization of supramolecular photosensitizers were further investigated by flow cytometry and confocal laser scanning microscopy (CLSM), and the result indicated that TPPC6-SS-Ada/PEG-beta-CD micelles could be effectively up-taken by MCF-7 cells. Furthermore, the phototoxicity evaluated by an MTT assay showed that TPPC6-SS-Ada/PEG-beta-CD micelles have very low dark toxicity but greater photo-toxicity compared to free porphyrin. Thus, TPPC6-SS-Ada/PEG-beta-CD micelles would provide the potential application for photosensitizer delivery.