RNA-cleaving DNAzymes (RCDs) are catalytically active DNA molecules that cleave a wide range of RNA targets with extremely high sequence-selectivity, but none is able to faithfully discriminate methylated from unmethylated RNA (typically <30-fold). We report the first efforts to isolate RCDs from a random-sequence DNA pool by selection that cleave RNA/DNA chimera containing -methyladenosine (mA), one of the most prevalent RNA modifications that plays important regulatory roles in gene expression and human cancers. A -acting deoxyribozyme, RCD1-S2, exhibits an observed rate constant ( ) of 5.
View Article and Find Full Text PDFUracil-DNA glycosylase (UDG), an enzyme for repairing uracil-containing DNA damage, is crucial for maintaining genomic stability. Simple and fast quantification of UDG activity is essential for biological assay and clinical diagnosis, since its aberrant level is associated with DNA damage and various diseases. Herein, we developed a fully integrated "sample in-signal out" distance-based paper analytical device (dPAD) for visual quantification of UDG using a flow-controlled uracil-rich DNA hydrogel (URDH).
View Article and Find Full Text PDFWe reported a colorimetric paper-based device by integrating the modified acid RNA-cleaving DNAzymes (MaRCD-EC1) for highly sensitive (detection limit = 10 CFU mL), and rapid (within 30 min) detection of without amplification. This device exhibited a clinical sensitivity of 100% and a specificity of 100% in identifying -associated urinary tract infections (UTIs) using the clinical urine samples.
View Article and Find Full Text PDFA CRISPR/Cas system represents an innovative tool for developing a new-generation biosensing and diagnostic strategy. However, the off-target issue (, mistaken cleavage of nucleic acid targets and reporters) remains a great challenge for its practical applications. We hypothesize that this issue can be overcome by taking advantage of the site-specific cleavage ability of RNA-cleaving DNAzymes.
View Article and Find Full Text PDFFoodborne pathogens pose a serious risk to human health, and the simple and rapid detection of such bacteria in complex food matrices remains challenging. Herein, we present the selection and characterization of a novel RNA-cleaving fluorogenic DNAzyme, named RFD-BC1, with exceptional specificity for (), a pathogen strongly associated with fatal food poisoning cases. RFD-BC1 was activated by a protein secreted specifically by whole viable and displayed an optimum pH distinct from the selection pH, with a rate constant of approximately 0.
View Article and Find Full Text PDFWe report on the first efforts to isolate acidic RNA-cleaving DNAzymes (aRCDs) from a random-sequence DNA pool by in vitro selection that are activated by a microbe (), at pH 5.3. Importantly, these -responsive aRCDs only require monovalent metal ions as cofactors for cleaving a fluorogenic chimeric DNA/RNA substrate.
View Article and Find Full Text PDFRapid detection of single nucleotide polymorphisms (SNPs) in the CYP2C19 gene is of great significance for clopidogrel-accurate medicine. CRISPR/Cas systems have been increasingly used in SNP detection due to their single-nucleotide mismatch specificity. PCR, as a powerful amplification tool, has been incorporated into the CRISPR/Cas system to improve the sensitivity.
View Article and Find Full Text PDFclustered regularly interspaced short palindromic repeats (CRISPR)-Cas systems are increasingly used in biosensor development. However, directly translating recognition events for non-nucleic acid targets by CRISPR into effective measurable signals represents an important ongoing challenge. Herein, it is hypothesized and confirmed that CRISPR RNAs (crRNAs) in a circular topology efficiently render Cas12a incapable of both site-specific double-stranded DNA cutting and nonspecific single-stranded DNA trans cleavage.
View Article and Find Full Text PDFThe use of polyoxometalate clusters (POMs) with multitudinous structures and surface properties as building blocks has sparked the development of cluster-assembled materials with many prospective applications. In comparison to classic molecules and assembly processes, control over the steric interactions and linkage of large POMs to achieve superlattices with multiple levels of organization remains a great challenge. This work presents a universal approach to modulate the spatial coordination behavior and configurations, and achieves a class of cluster superlattice architectures formed by linear alignment and two-dimensional arrangement of POM units.
View Article and Find Full Text PDFG protein-coupled receptor 39 (GPR39) is a zinc-sensing receptor (ZnR) that can sense changes in extracellular Zn, mediate Zn signal transmission, and participate in the regulation of numerous physiological activities in living organisms. For example, GPR39 activates the extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) and phosphatidylinositol3-kinase/protein kinase B (PI3K/AKT) signaling pathways upon Zn stimulation, enhances the proliferation and differentiation of colonic cells, and regulates ion transport, as well as exerting other functions. In recent years, with the increased attention to animal gut health issues and the intensive research on GPR39, GPR39 has become a potential target for regulating animal intestinal health.
View Article and Find Full Text PDFBioaerosols are the biological materials in the air, which may cause a continuous threat to human health. However, there are many challenges in monitoring bioaerosols such as lack of sensitivity and selectivity. Herein, we synthesized a series of nanohybrids containing zeolitic imidazolate frameworks (ZIFs) and covalent organic frameworks (COFs) to construct an electrochemical aptasensor for detecting adenosine triphosphate (ATP), a biomarker for bioaerosols.
View Article and Find Full Text PDFWe described a new system termed droplet DNAzyme-coupled rolling circle amplification (dDRCA) that can selectively detect bacteria from clinical urine samples with single-cell sensitivity within 1.5 h compared with the several hours needed for traditionally used culture-based methods.
View Article and Find Full Text PDFBacteria and viruses are both important pathogens causing intestinal infections, and studies on their pathogenic mechanisms tend to focus on one pathogen alone. However, bacterial and viral co-infections occur frequently in clinical settings, and infection by one pathogen can affect the severity of infection by another pathogen, either directly or indirectly. The presence of synergistic or antagonistic effects of two pathogens in co-infection can affect disease progression to varying degrees.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
July 2021
Enterotoxigenic Escherichia coli (ETEC) F4ac is a major constraint to the development of the pig industry, which is causing newborn and post-weaning piglets diarrhea. Previous studies proved that FaeG is the major fimbrial subunit of F4ac E. coli and efficient for bacterial adherence and receptor recognition.
View Article and Find Full Text PDFZinc (Zn) is an essential trace element in living organisms and plays a vital role in the regulation of both microbial virulence and host immune responses. A growing number of studies have shown that zinc deficiency or the internal Zn concentration does not meet the needs of animals and microbes, leading to an imbalance in zinc homeostasis and intracellular signalling pathway dysregulation. Competition for zinc ions (Zn) between microbes and the host exists in the use of Zn to maintain cell structure and physiological functions.
View Article and Find Full Text PDFZinc is the second trace element of living organisms after iron. Given its crucial importance, mammalian hosts restrict the bioavailability of Zinc ions (Zn) to bacterial pathogens. As a countermeasure, pathogens utilize high affinity Zn transporters, such as ZnuACB to compete with the host for zinc.
View Article and Find Full Text PDFLithium-sulfur (Li-S) batteries are one of the most promising candidates for meeting the emerging market demands for energy storage, and have the advantages including high energy density and low cost. However, the practical application of Li-S batteries is hindered by the lithium polysulfide (LiPS) shuttle, which induces low sulfur utilization and unsatisfactory capacity retention. To address this problem, recent studies have focused on improving the transformation of LiPS into insoluble Li2S2/Li2S through methods beyond physical or chemical adsorption.
View Article and Find Full Text PDFHigh quality graphene (HQG) offers unconventional properties and is desirable for a variety of applications. However, facile solution processing (especially in water) and chemical bonding of functional components with the aim of achieving high-yield, green, and controllable synthesis of advanced graphene materials are of great concern. Herein, the surface chemistry of HQG is effectively tailored using a hydrophobic-driven assembly of cellulose macromolecules (CM) with various functionalities.
View Article and Find Full Text PDFBACKGROUND Patients with advanced non-small cell lung cancer (NSCLC) treated with cisplatin, also termed cis-diamminedichloroplatinum (CDDP) or diamminedichloroplatinum (DDP), may develop chemoresistance. This study aimed to investigate the role of long non-coding RNA (lncRNA) X-inactive specific transcript (XIST) and multidrug resistance-1 (MDR1) in tumor tissue samples and the chemoresistant human NSCLC cell lines, H460/DDP and A549/DDP, and in a murine A549/DDP tumor xenograft. MATERIAL AND METHODS Tissue samples were from patients with NSCLC who responded cisplatin (DDP-sensitive) (n=24), patients with NSCLC unresponsive to cisplatin (DDP-resistant) (n=30), and normal lung tissue (n=25).
View Article and Find Full Text PDFMater Sci Eng C Mater Biol Appl
September 2017
In order to developing a sort of flexible fibrous mats with outstanding and durable antibacterial activates, silver nanowires incorporated into polyvinyl alcohol (PVA) nanofibers were fabricated by electrospun method. Uniform Ag nanowires (NWs) were synthesized through a template-free method of solvothermal combined with polyol process, and then, they were dispersed in PVA solution. At last, Ag NWs embedded in PVA (Ag NWs/PVA) hybrid nanofibrous films were gained by electrospun of the mixed solution.
View Article and Find Full Text PDFSilver nanoparticle-embedded polyvinyl alcohol (PVA) nanofibers were prepared through electrospinning technique, using as antimicrobial agents and surface-enhanced Raman scattering (SERS) substrates. Ag nanoparticles (NPs) were synthesized in liquid phase, followed by evenly dispersing in PVA solution. After electrospinning of the mixed solution at room temperature, the PVA embedded with Ag NPs (Ag/PVA) composite nanofibers were obtained.
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