Construction of a pH-sensitive self-assembly in aqueous solutions based on a dansyl-modified β-cyclodextrin

Abstract

Here we present a pH-responsive self-assembly based on a β-cyclodextrin (β-CD) derivative bearing a dansyl terminus (βCD-C₆–Dns). Vesicular structures were formed over the entire studied pH range (8.5–0.7); however, the molecular configuration and packing within the vesicles were different at different pH values. Intramolecular host–guest complexation occurred mainly between the dansyl group and β-CD at pH values where the dansyl group was not protonated. The alkyl chain also acted as a competitive guest to form host–guest inclusions as confirmed by 2D ¹H NMR measurements. The pH-responsive βCD-C₆–Dns vesicles have potential application prospects in pH-controlled drug release based on the low cytotoxicity of βCD-C₆–Dns.