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Synthetic biochemical circuits (e.g., DNA circuits) remain at the forefront of intracellular biosensing tasks yet are hindered by the undesired off‐site activation and the accompanying signal leakage. Herein, the study attempts to overcome this limitation by developing a simple‐yet‐powerful endogenous glutathione (GSH)‐regulating tactic that permits robust and distinguishable on‐site microRNA (miRNA) imaging under disturbed redox homeostasis. Specifically, a hierarchically activated catalytic DNA (HAD) circuit is fabricated by grafting the disulfide linkage within entropy‐driven DNA circuitry (EDC) reactants. It is exemplified that this HAD system promises the spatiotemporally selective microRNA‐21 (miR‐21) imaging in living cells and the robust differentiation of tumor cells from normal cells. The correlationship between GSH and miRNA is extensively explored in live cells, and can substantially expand the toolbox of DNA circuits for profiling intracellular biochemical processes. [ABSTRACT FROM AUTHOR]

Non‐invasive cell regulation represents a promising approach for on‐site cell modulation, but is confronted with inaccuracy or poor cell selectivity. Herein, by virtue of the interfacial‐activated concatenate DNA circuit, an activated recombination‐to‐modulation (ARM) machinery is developed to achieve accurate membrane imaging and effective cell modulation. Bioorthogonal signal transduction through the catalytic hairpin assembly circuit can continuously regenerate triggers for activating the subsequent circuit, with no activator consumption and occupation. The ARM strategy utilizes the amplified hybridization chain reaction to sensitively rearrange membrane receptors for blocking the related signaling pathways and indirectly modulating cell behaviors. Based on these two membrane receptor inputs, the controllably‐activated ARM strategy enables the identification of target cells among similar interfering cells with high accuracy and sensitivity. This machinery has demonstrated good performance in the efficient inhibition of tumor metastasis via the disruption of HGF/c‐Met‐signaling pathway. The modular‐designed ARM machinery provides a general platform for non‐invasive and specific cell modulation, suggesting a broad opportunity for advanced exploration of cellular metabolism behaviors. [ABSTRACT FROM AUTHOR]

Synthetic catalytic DNA circuits have been recognized as a promising signal amplification toolbox for sensitive intracellular imaging, yet their selectivity and efficiency are always constrained by uncontrolled off‐site signal leakage and inefficient on‐site circuitry activation. Thus, the endogenously controllable on‐site exposure/activation of DNA circuits is highly desirable for achieving the selective imaging of live cells. Herein, an endogenously activated DNAzyme strategy was facilely integrated with a catalytic DNA circuit for guiding the selective and efficient microRNA imaging in vivo. To prevent the off‐site activation, the circuitry constitute was initially caged without sensing functions, which could be selectively liberated by DNAzyme amplifier to guarantee the high‐contrast microRNA imaging in target cells. This intelligent on‐site modulation strategy can tremendously expand these molecularly engineered circuits in biological systems. [ABSTRACT FROM AUTHOR]

The wide extracellular‐intracellular distribution of microRNA requires the on‐site, robust and efficient activation of catalytic DNA circuits inside live cells. Herein, we develop an efficient non‐enzymatic circuitry activation strategy to realize the orthogonally controlled catalytic DNA (CCD) circuit for achieving high‐fidelity in vivo microRNA imaging through multiply guaranteed molecular recognition and progressively accelerated signal amplification. For predictable on‐site activation and useful catalytic efficiency, the dominating circuitry fuel strand was initially split into inactive fuel subunits that were grafted into an auxiliary catalytic circuit. There, the in‐cell‐specific mRNA triggered the orthogonal amplification of the active fuel strands for sensitive target detection through the chief entropy‐driven catalytic DNA circuit. We believe that the on‐site orthogonal circuitry activation method can contribute to clinical diagnosis and prognosis. [ABSTRACT FROM AUTHOR]

Lowly expressed analyte in complex cytoplasmic milieu necessitates the development of non‐enzymatic autocatalytic DNA circuits with high amplification and anti‐interference performance. Herein, we engineered a versatile and robust stimuli‐responsive autocatalytic hybridization assembly (AHA) circuit for high‐performance in vivo bioanalysis. Under a moderately confined condition, the initiator motivated the autonomous and cooperative cross‐activation of cascade hybridization reaction and catalytic DNA assembly for generating an exponentially amplified readout without the parasite steric hindrance and random diffusion side effects. The AHA circuit was systematically investigated by a series of experimental studies and theoretical simulations. The successively guaranteed target recognition and synergistically accelerated signal‐amplification enabled the sensitive and selective detection of analyte, and realized the robust miRNA imaging in living cells and mice. This autocatalytic DNA circuit could substantially expand the toolbox for accurate diagnosis and programmable therapeutics. [ABSTRACT FROM AUTHOR]

DNA Circuit, Fluorescence, RNA, Signal Amplification, Tumor Imaging Der am Wirkort aktivierte CCD-Schaltkreis hat erhebliches Potenzial für die hochpräzise In-vivo-Bildgebung von microRNA. Keywords: DNA Circuit; Fluorescence; RNA; Signal Amplification; Tumor Imaging EN DNA Circuit Fluorescence RNA Signal Amplification Tumor Imaging 1 1 1 11/03/22 20221107 NES 221107 B Eine nicht-enzymatische b Aktivierungsstrategie mittels multipler molekularer Erkennungsereignisse und progressiv beschleunigter Signalverstärkung führte zu einem orthogonal gesteuerten katalytischen DNA-Schaltkreis (CCD), wie Fuan Wang et al. in ihrem Forschungsartikel berichten (e202206529). [Extracted from the article]

Back Cover: On-Site Non-enzymatic Orthogonal Activation of a Catalytic DNA Circuit for Self-Reinforced In Vivo MicroRNA Imaging (Angew. Keywords: DNA Circuit; Fluorescence; RNA; Signal Amplification; Tumor Imaging EN DNA Circuit Fluorescence RNA Signal Amplification Tumor Imaging 1 1 1 11/03/22 20221107 NES 221107 B A non-enzymatic circuitry b activation strategy can realize an orthogonally controlled catalytic DNA (CCD) circuit through multiple molecular recognition events and progressively accelerated signal amplification, as reported by Fuan Wang and co-workers in their Research Article (e202206529). DNA Circuit, Fluorescence, RNA, Signal Amplification, Tumor Imaging. [Extracted from the article]