Enzyme-Free Dynamic DNA Reaction Networks for On-Demand Bioanalysis and Bioimaging.

ConspectusThe pursuit of in-depth studying the nature and law of life activity has been dominating current research fields, ranging from fundamental biological studies to applications that concern synthetic biology, bioanalysis, and clinical diagnosis. Motivated by this intention, the spatiotemporally controlled and in situ analysis of living cells has been a prospective branch by virtue of high-sensitivity imaging of key biomolecules, such as biomarkers. The past decades have attested that deoxyribonucleic acid (DNA), with biocompatibility, programmability, and customizable features, is a competitive biomaterial for constructing high-performance molecular sensing tools.

Joint association of air pollution exposure and inflammation-related proteins in relation to infant lung function.

Background And Aim: Systemic inflammation is one potential mechanism underlying negative impact of air pollution on lung function. Levels of inflammation-related proteins have the potential to characterize infants' susceptibility to air pollution induced lung function impairment. This study aimed to examine the interplay between air pollution exposure and inflammation-related proteins on lung function in 6-months-old infants.

Spatiotemporally Programmed Disassembly of Multifunctional Integrated DNAzyme Nanoplatfrom for Amplified Intracellular MicroRNA Imaging.

The sensing performance of DNAzymes in live cells is tremendously hampered by the inefficient and inhomogeneous delivery of DNAzyme probes and their incontrollable off-site activation, originating from their susceptibility to nuclease digestion. This requires the development of a more compact and robust DNAzyme-delivering system with site-specific DNAzyme activation property. Herein, a highly compact and robust Zn@DDz nanoplatform is constructed by integrating the unimolecular microRNA-responsive DNA-cleaving DNAzyme (DDz) probe with the requisite DNAzyme Zn -ion cofactors, and the amplified intracellular imaging of microRNA via the spatiotemporally programmed disassembly of Zn@DDz nanoparticles is achieved.

The compact integration of a cascaded HCR circuit for highly reliable cancer cell discrimination.

The accurate identification of multiple biomarkers involved in disease plays a vital role in effectively distinguishing cancer cells from normal cells, facilitating reliable cancer diagnosis. Motivated by this knowledge, we have engineered a compact and clamped cascaded DNA circuit for specifically discriminating cancer cells from normal cells the amplified multi-microRNA imaging strategy. The proposed DNA circuit combines the traditional cascaded DNA circuit with multiply localized responsive character through the elaboration of two super-hairpin reactants, thus concurrently streamlining the circuit components and realizing localization-intensified cascaded signal amplification.

Tailoring a Minimal Self-Replicate DNA Circuit for Highly Efficient Intracellular Imaging of microRNA.

Trace analyte detection in complex intracellular environment requires the development of simple yet robust self-sufficient molecular circuits with high signal-gain and anti-interference features. Herein, a minimal non-enzymatic self-replicate DNA circuitry (SDC) system is proposed with high-signal-gain for highly efficient biosensing in living cells. It is facilely engineered through the self-stacking of only one elementary cascade hybridization reaction (CHR), thus is encoding with more economic yet effective amplification pathways and reactants.

An entropy-driven DNA nanomachine for microRNA detection using a personal glucose meter.

Herein, we developed a reliable and portable biosensor (TDR-PGM nanomachine) for the sensitive detection of microRNA by integrating an efficient toehold-mediated strand displacement reaction module (TDR) and a personal glucose meter (PGM). The system provides a versatile methodology for microRNA detection in real samples and holds broad prospects in point-of-care diagnosis.

Monitoring and modulating a catalytic hybridization circuit for self-adaptive bioorthogonal DNA assembly.

Constructing artificial domino nanoarchitectures, especially dynamic DNA circuits associated with the actuation of biological functions inside live cells, represents a versatile and powerful strategy to regulate the behaviors and fate of various living entities. However, the stepwise operation of conventional DNA circuits always relies on freely diffusing reactants, which substantially slows down their operation rate and efficiency. Herein, a self-adaptive localized catalytic circuit (LCC) is developed to execute the self-sustained bioorthogonal assembly of DNA nanosponges within a crowded intracellular environment.

Ambient air pollution and inflammation-related proteins during early childhood.

Background And Aim: Experimental studies show that short-term exposure to air pollution may alter cytokine concentrations. There is, however, a lack of epidemiological studies evaluating the association between long-term air pollution exposure and inflammation-related proteins in young children. Our objective was to examine whether air pollution exposure is associated with inflammation-related proteins during the first 2 years of life.

Air pollution, metabolites and respiratory health across the life-course.

Previous studies have explored the relationships of air pollution and metabolic profiles with lung function. However, the metabolites linking air pollution and lung function and the associated mechanisms have not been reviewed from a life-course perspective. Here, we provide a narrative review summarising recent evidence on the associations of metabolic profiles with air pollution exposure and lung function in children and adults.

Multiply Guaranteed and Successively Amplified Activation of a Catalytic DNA Machine for Highly Efficient Intracellular Imaging of MicroRNA.

DNA amplification machines show great promise for intracellular imaging, yet are always constrained by off-site machinery activation or signal leakage, originating from the inherent thermodynamically driven hybridization between machinery substrates. Herein, an entropy-driven catalytic DNA amplification machine is integrated with the on-site amplified substrate exposure procedure to realize the high-contrast in vivo imaging of microRNA (miRNA). The key machinery substrate (fuel strands) is initially split into substrate subunits that are respectively grafted into an auxiliary DNA polymerization amplification accessory for eliminating the undesired signal leakage.

On-Site Non-enzymatic Orthogonal Activation of a Catalytic DNA Circuit for Self-Reinforced In Vivo MicroRNA Imaging.

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.

Modular Assembly of a Concatenated DNA Circuit for In Vivo Amplified Aptasensing.

Probing endogenous molecular profiles in living entities is of fundamental significance to decipher biological functions and exploit novel theranostics. Despite programmable nucleic acid-based aptasensing systems across the breadth of molecular imaging, an aptasensing system enabling in vivo imaging with high sensitivity, accuracy, and adaptability is highly required yet is still in its infancy. Artificial catalytic DNA circuits that can modularly integrate to generate multiple outputs from a single input in an isothermal autonomous manner, have supplemented powerful toolkits for intracellular biosensing research.

An Isothermal Autocatalytic Hybridization Reaction Circuit for Sensitive Detection of DNA Methyltransferase and Inhibitors Assay.

Abnormal DNA methylation contributes to the annoying tumorigenesis and the elevated expression of methylation-related methyltransferase (MTase) is associated with many diseases. Hence DNA MTase could serve as a promising biomarker for cancer-specific diagnosis as well as a potential therapeutic target. Herein, we developed an isothermal autocatalytic hybridization reaction (AHR) circuit for the sensitive detection of MTase and its inhibitors by integrating the catalytic hairpin assembly (CHA) converter with the hybridization chain reaction (HCR) amplifier.

Theoretical Study on the Electronic Structure and Magnetic Properties Regulation of Janus Structure of M'MCO 2D MXenes.

Motivated by the recent successful synthesis of Janus monolayer of transition metal (TM) dichalcogenides, MXenes with Janus structures are worthy of further study, concerning its electronic structure and magnetic properties. Here, we study the effect of different transition metal atoms on the structure stability and magnetic and electronic properties of M'MCO (M' and M = V, Cr and Mn). The result shows the output magnetic moment is contributed mainly by the d orbitals of the V, Cr, and Mn atoms.

Enzyme-Free Autocatalysis-Driven Feedback DNA Circuits for Amplified Aptasensing of Living Cells.

Aptasensors with high specificity have emerged as powerful tools for understanding various biological processes, thus providing tremendous opportunities for clinical diagnosis and prognosis. However, their applications in intracellular molecular imaging are largely impeded due to the low anti-interference capacity in biological environments and the moderate sensitivity to targets. Herein, a robust enzyme-free autocatalysis-driven feedback DNA circuit is devised for amplified aptasensing, for example, adenosine triphosphate (ATP) and thrombin, with a significantly improved sensitivity in living cells.

Bioorthogonal regulation of DNA circuits for smart intracellular microRNA imaging.

Catalytic DNA circuits represent a versatile toolbox for tracking intracellular biomarkers yet are constrained with low anti-interference capacity originating from their severe off-site activation. Herein, by introducing an unprecedented endogenous DNA repairing enzyme-powered pre-selection strategy, we develop a sequential and specific on-site activated catalytic DNA circuit for achieving the cancer cell-selective imaging of microRNA with high anti-interference capacity. Initially, the circuitry reactant is firmly caged by an elongated stabilizing duplex segment with a recognition/cleavage site of a cell-specific DNA repairing enzyme, which can prevent undesired signal leakage prior to its exposure to target cells.

A Self-Catabolic Multifunctional DNAzyme Nanosponge for Programmable Drug Delivery and Efficient Gene Silencing.

DNAzyme-based gene therapy holds immense prospects for effectively treating severe diseases, yet is constrained with inefficient delivery and unconditional activation. Herein, we designed a bioinspired self-catabolic DNA nanocapsule for sustaining tumor-specific cascade activation of therapeutic DNAzyme. The exquisite DNAzyme was temporarily masked by the self-excising DNAzyme in the hierarchical rolling circle replication (RCR) nanostructures, thus stayed in an inactive state in physiological fluids.

Breast Cancer Screening Trends among Lower Income Women of New York: A Time-Series Evaluation of a Population-Based Intervention.

Objective: This study aimed to compare the screening rate trends of mammography among New York State's lower-income women and the higher-income women from 1988 to 2010, and evaluate the potential influence of New York State's Breast Cancer Early Detection Program (introduced in 1994) on the mammography use rates of lower-income women.

Materials And Methods: Lower-income women are defined as women aged 40 and over whose household income is lower than 250% of the single member household federal poverty level (FPL) in the year that they participated in the survey. Higher-income women are defined as women aged 40 and over whose income is greater than 250% of the five-person household FPL.

Autocatalytic DNAzyme assembly for amplified intracellular imaging.

The autocatalytic HCR-DNAzyme platform was constructed as a versatile amplification platform for intracellular microRNA imaging by integrating hybridization chain reaction (HCR) circuit with DNAzyme biocatalysis. The HCR-assembled multifunctional DNAzyme nanowires produce new HCR triggers and numerous transducer DNAzyme amplifier, and thus shows great promise in earlier cancer diagnosis.

Analysis of high-resolution computed tomography phenotypes and pulmonary function in chronic obstructive pulmonary disease.

Objective: To explore the correlation between high-resolution computed tomography (HRCT) phenotype and pulmonary function in patients with chronic obstructive pulmonary disease (COPD).

Methods: Fifty-six patients with COPD were retrospectively evaluated using pulmonary function tests (PFTs) and HRCT, and phenotypic pulmonary function parameters were analyzed.

Results: Thirty-one patients were classified as having imaging phenotype A, 11 were phenotype E, and 14 were phenotype M.

Nonviolent Self-Catabolic DNAzyme Nanosponges for Smart Anticancer Drug Delivery.

The development of self-assembled DNA nanomedicine requires a facile and accurate DNA degradation strategy for precisely programmable drug release. Conventional DNA catabolic strategies are restrained with the fragile and unclear enzymatic reactions that might lead to inefficient and uncontrollable digestion of DNA scaffolds and thus might bring undesirable side effects to the sophisticated biosystems. Herein we reported a versatile self-sufficient DNAzyme-driven drug delivery system consisting of the rolling circle polymerized DNAzyme-substrate scaffolds and the encapsulated pH-responsive ZnO nanoparticles (NPs).

Ratiometric fluorescence sensing of mercuric ion based on dye-doped lanthanide coordination polymer particles.

This work focused on the development of a novel ratiometric fluorescence sensor for detection of Hg by using dye-doped lanthanide infinite coordination polymer (Ln-ICP) particles. The dye-doped Ln-ICP used herein was prepared by self-assemble of adenosine monophosphate (AMP) with Ce and Tb (Ce/Tb-AMP) through self-adaptive chemistry, in which the fluorescent dye coumarin was encapsulated during the assembly process as a guest molecule. Under 310 nm irradiation, the obtained coumarin@Ce/Tb-AMP itself emitted characteristic green luminescence of Tb, accompanied with a weak fluorescence at 445 nm originated from coumarin encapsulated in the Ce/Tb-AMP networks.