Controllable DNA hybridization by host–guest complexation-mediated ligand invasion

Dynamic regulation of nucleic acid hybridization is fundamental for switchable nanostructures and controllable functionalities of nucleic acids in both material developments and biological regulations. In this work, we report a ligand-invasion pathway to regulate DNA hybridization based on host–guest interactions. We propose a concept of recognition handle as the ligand binding site to disrupt Watson–Crick base pairs and induce the direct dissociation of DNA duplex structures. Taking cucurbit[7]uril as the invading ligand and its guest molecules that are integrated into the nucleobase as recognition handles, we successfully achieve orthogonal and reversible manipulation of DNA duplex dissociation and recovery. Moreover, we further apply this approach of ligand-controlled nucleic acid hybridization for functional regulations of both the RNA-cleaving DNAzyme in test tubes and the antisense oligonucleotide in living cells. This ligand-invasion strategy establishes a general pathway toward dynamic control of nucleic acid structures and functionalities by supramolecular interactions.