Supramolecular amphiphiles based on cyclodextrin and hydrophobic drugs†
Herein we report a novel “supra-prodrug-type” superamphiphile design: via a redox-sensitive self-immolative linker, a hydrophobic drug molecule was labeled with an azobenzene moiety, which was designed to be capped by a hydrophilic cyclodextrin (CD) molecule. Four clinical hydrophobic drugs, 7-ethyl-10-hydroxycamptothecin (SN-38), doxorubicin (DOX), phenytoin and aliskiren, were investigated to directly participate in building a novel class of superamphiphile, in which the CD moiety plays as the hydrophilic head and the drug as the hydrophobic tail. This novel type of superamphiphile can further self-assemble into vesicular or tubular structures, characterized by transmission electron microscope (TEM), scanning electron microscope (SEM) and dynamic light scattering (DLS). The possible self-assembly mechanism is given based on multiple pieces of evidence, including nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and Ultraviolet-visible spectroscopy (UV-vis) results. The reconversion kinetics of the prodrug as a function of glutathione (GSH) in the presence or absence of UV irradiation is presented. Cell experiments indicate that the “supra-prodrug” can be facially endowed with a function by a simple substitution with another functionalized host. We hope this work can provide new reference in the field of drug screening, formulation and delivery.