A DNA Logic Circuit Equipped with a Biological Amplifier Loaded into Biomimetic ZIF-8 Nanoparticles Enables Accurate Identification of Specific Cancers In Vivo.

DNA logic circuits (DLC) enable the accurate identification of specific cell types, such as cancer cells, but they face the challenges of weak output signals and a lack of competent platforms that can efficiently deliver DLC components to the target site in the living body. To address these issues, we rationally introduced a cascaded biological amplifier module based on the Primer Exchange Reaction inspired by electronic circuit amplifier devices. As a paradigm, three abnormally expressed Hela cell microRNAs (-30a, -17, and -21) were chosen as "AND" gate inputs. DLC response to these inputs was boosted by the amplifier markedly enhancing the output signal. More importantly, the encapsulation of DLC and amplifier components into ZIF-8 nanoparticles resulted in their efficient delivery to the target site, successfully distinguishing the Hela tumor subtype from other tumors in vivo. Thus, we envision that this strategy has great potential for clinical cancer diagnosis.

Neutrophil-Membrane-Coated Biomineralized Metal-Organic Framework Nanoparticles for Atherosclerosis Treatment by Targeting Gene Silencing.

Antisense oligonucleotides (ASOs) are promising tools for gene silencing and have been exploited as therapeutics for human disease. However, delivery of therapeutic ASOs to diseased tissues or cells and subsequent escape from the endosomes and release of ASO in the cytosol remain a challenge. Here, we reported a neutrophil-membrane-coated zeolitic imidazolate framework-8 (ZIF-8) nanodelivery platform (AM@ZIF@NM) for the targeted transportation of ASOs against microRNA-155 (anti-miRNA-155) to the endothelial cells in atherosclerotic lesions. Neutrophil membrane could improve plaque endothelial cells targeting through the interaction between neutrophil membrane protein CD18 and endothelial cell membrane protein intercellular adhesion molecule-1 (ICAM-1). The ZIF-8 "core" provided high loading capacity and efficient endolysosomal escaping ability. Delivery of anti-miR-155 effectively downregulated miR-155 expression and also saved the expression of its target gene BCL6. Moreover, RELA expression and the expression of its downstream target genes CCL2 and ICAM-1 were correspondingly reduced. Consequently, this anti-miR-155 nanotherapy can inhibit the inflammation of atherosclerotic lesions and alleviate atherosclerosis. Our study shows that the designed biomimetic nanodelivery system has great application prospects in the treatment of other chronic diseases.

A novel multiplex signal amplification strategy based on microchip electrophoresis platform for the improved separation and detection of microRNAs.

A multiplex fluorescence signal amplification method based on microchip electrophoresis (MCE) platform was developed for the improvements in the separation and detection of microRNAs. The method used two kinds of fluorescein amidite labeled DNA signal probes to hybridize with its target microRNAs, utilizing T7 exonuclease assisting target circling realized the fluorescence signal amplification. Then, two kinds of fluorescein amidite labeled DNA segments with different size were separated and detected on the MCE-laser induced fluorescence detection platform. The microRNAs-126 and microRNAs-141 were used as model analytes in the proof-of-concept experiments. Two calibration curves between the fluorescence intensity and microRNAs concentration all showed good linearity in the range of 0.025-20 nM. The correlation coefficients obtained were 0.9975 and 0.9925, respectively. The limits of detection for two kinds of microRNAs were estimated to all be 15 pM. By spiking T24 cell lysate samples with varying amounts of miRNA-126 and miRNA-141, the recovery of analytes ranged from 96.0% to 115%, and the relative standard deviations are lower than 5.5%. The present method showed high sensitivity and selectivity, which has a promising application in biomedical research.

An ultrasensitive microchip electrophoresis assay based on separation-assisted double cycling signal amplification strategy for microRNA detection in cell lysate.

Microchip electrophoresis (MCE) assay is an analysis technique with low consumption and high automation. It is a useful tool in biomedical research and clinical diagnosis. However, the low detection sensitivity limits its application in trace biomarker analysis because of its extremely small sample size. To address the need for high sensitivity in MCE, we have developed an ultrasensitive MCE method based on a separation-assisted double cycling signal amplification strategy for the detection of microRNA (miRNA) in cell lysate. In this method, two short single-stranded DNAs P1 and P2 complement each other to form a duplex DNA probe (P1/P2). In the presence of target miRNA, P2 in the P1/P2 probe can be displaced to form double-stranded miRNA/P1. Then, the degradation of P1 in miRNA/P1 by T7 Exo releases the miRNA, and the released miRNA participates in a displacement reaction with another P1/P2 probe to complete the first cycle. The displaced free P2 hybridizes with the hairpin fluorescence probe (MB) to form the P2/MB duplex, which can also be degraded by T7 Exo to release P2. The released P2 can bind with another MB probe to complete the second cycle. By using MCE-laser-induced fluorescence (LIF) as separation and detection platform and miRNA-141 as model analyte, the proposed MCE assay can detect miRNA-141 at concentrations as low as 8.0 fM, which is the highest sensitivity achieved to date for an MCE assay. This method for detecting trace miRNA holds great potential in biomedical research and clinical diagnosis.