Enzyme-Responsive Molecular Assemblies Based on Host-Guest Chemistry

Recent years have witnessed a growing interest in the design of enzyme-responsive molecular assemblies that hold appealing applications in the fields of disease-related sensing, imaging, and drug delivery. Cyclodextrins (CDs) are amylase-cleavable host molecules that can associate with surfactants, alkanes, alkyl amines, fatty alcohols, and aromatic compounds to form diverse supramolecular structures. In this work, we report a versatile supramolecular platform to construct enzyme-responsive nanosystems via host-guest interactions, in which complexation between CDs and surfactants eventually leads to the formation of a variety of nanostructures such as vesicles and microtubes. These supramolecular structures are capable of loading water-soluble molecules or functional nanoparticles, which can be actively released on-demand in the presence of alpha-amylase. This universal strategy to fabricate enzyme-responsive supramolecular systems was further demonstrated with a range of surfactants with anionic, cationic, and nonionic headgroups. Our results highlight a versatile platform for the exploration of biologically responsive self-assembly with potential applications as controlled-release systems and microrobots.