Efficient Intracellular MicroRNA Imaging Based on the Localized and Self-Sustainable Catalytic DNA Assembly Circuit

Abstract

Building dynamic biological networks, especially DNA circuits, has provided a powerful prospect for exploring the intrinsic regulation processes of live cells. Nevertheless, for efficient intracellular microRNA analysis, the available multi-component circuits are constrained by their limited operating speed and efficiency due to the free diffusion of reactants. Herein, we developed an accelerated Y-shaped DNA catalytic (YDC) circuit for high-efficiency intracellular imaging of microRNA. By grafting the catalytic hairpin assembly (CHA) reactants into an integrated Y-shaped scaffold, the CHA probes were concentrated in a compact space, thus achieving high signal amplification. Profiting from the spatially confined reaction and the self-sustainably assembled DNA products, the YDC system facilitated reliable and in situ microRNA imaging in live cells. Compared with the homogeneously dispersed CHA reactants, the integrated YDC system could efficiently promote the reaction kinetics as well as the uniform delivery of CHA probes, thus providing a robust and reliable analytical tool for disease diagnosis and monitoring.

DNA nanotechnology-based nucleic acid delivery systems for bioimaging and disease treatment

“…79 Later, Wang's group developed a localized and self-sustainable Y-shaped DNA catalytic circuit for the in situ imaging of intracellular miRNA. 80 By grafting three CHA hairpin reactants on a Y-shaped scaffold, the reactants were concentrated in a constrained space to obtain accelerated reaction kinetics and high-contrast readout signals. The products of former CHA reactions could be applied as templates for subsequent CHA reactions to complete DNA self-sustained assembly and obtain cross-linked hyperbranched DNA products.…”