Preparation of vesicles and nanoparticles of amphiphilic cyclodextrins containing labile disulfide bonds

Amphiphilic cyclodextrin derivatives were prepared in which a disulfide bond connects the hydrophobic substituents to the macrocycle. These compounds were obtained by 1,3-dicyclohexylcarbodiimide-mediated coupling reactions of heptakis(6-amino-6-deoxy)-beta-cyclodextrins and disulfide-containing carboxylic acids of increasing hydrophobicity. To improve the water solubility of the cyclodextrins, oligo(ethylene glycol) substituents were grafted to the secondary side of the cyclodextrin molecules. The amphiphilic cyclodextrins form vesicles or nanoparticles in water, which disintegrate in the presence of the disulfide reducing agent dithiothreitol. Hydrophobic guest molecules are released from the nanoparticles upon cleavage of the disulfides.