Synthetic Host–Guest Assembly in Cells and Tissues: FastStable and Selective Bioorthogonal Imaging via Molecular Recognition

摘要

Bioorthogonal strategies are continuing to pave the way for new analytical tools in biology. Although a significant amount of progress has been made in developing covalent reaction based bioorthogonal strategies, balanced reactivity, and stability are often difficult to achieve from these systems. Alternatively, despite being kinetically beneficial, the development of noncovalent approaches that utilize fully synthetic and stable components remains challenging due to the lack of selectivity in conventional noncovalent interactions in the living cellular environment. Herein, we introduce a bioorthogonal assembly strategy based on a synthetic host–guest system featuring Cucurbit[7]uril (CB[7]) and adamantylamine (ADA). We demonstrate that highly selective and ultrastable host–guest interaction between CB[7] and ADA provides a noncovalent mechanism for assembling labeling agents, such as fluorophores and DNA, in cells and tissues for bioorthogonal imaging of molecular targets. Additionally, by combining with covalent reaction, we show that this CB[7]–ADA based noncovalent interaction enables simultaneousbioorthogonal labeling and multiplexed imaging in cells as well astissue sections. Finally, we show that interaction between CB[7] andADA fulfills the demands of specificity and stability that is requiredfor assembling molecules in the complexities of a living cell. Wedemonstrate this by sensitive detection of metastatic cancer-associatedcell surface protein marker as well as by showing the distributionand dynamics of F-actin in living cells.