Heteromultivalent DNA Enhances the Assembly Yield of Hybrid Nanoparticles and Facilitates Dynamic Disassembly for Bioanalysis Using ICP-MS.

To obtain enhanced physical and biological properties, various nanoparticles are typically assembled into hybrid nanoparticles through the binding of multiple homologous DNA strands to their complementary counterparts, commonly referred to as homomultivalent assembly. However, the poor binding affinity and limited controllability of homomultivalent disassembly restrict the assembly yield and dynamic functionality of the hybrid nanoparticles. To achieve a higher binding affinity and flexible assembly choice, we utilized the paired heteromultivalency DNA to construct hybrid nanoparticles and demonstrate their excellent assembly characteristics and dynamic applications. Specifically, through heteromultivalency, DNA-functionalized magnetic beads (MBs) and gold nanoparticles (AuNPs) were efficiently assembled. By utilizing ICP-MS, the assembly efficiency of AuNPs on MBs was directly monitored, enabling quantitative analysis and optimization of heteromultivalent binding events. As a result, the enhanced assembly yield is primarily attributed to the fact that heteromultivalency allows for the maximization of effective DNA probes on the surface of nanoparticles, eliminating steric hindrance interference. Subsequently, with external oligonucleotides as triggers, it was revealed that the disassembly mechanism of hybrid nanoparticles was initiated, which was based on an increased local concentration rather than toehold-mediated displacement of paired heteromultivalency DNA probes. Capitalizing on these features, an output platform was then established based on ICP-MS signals that several Boolean operations and analytical applications can be achieved by simply modifying the design sequences. The findings provide new insights into DNA biointerface interaction, with potential applications to complex logic operations and the construction of large DNA nanostructures.

Advances in the DNA Nanotechnology for the Cancer Biomarkers Analysis: Attributes and Applications.

The most commonly used clinical methods are enzyme-linked immunosorbent assay (ELISA) and quantitative PCR (qPCR) in which ELISA was applied for the detection of protein biomarkers and qPCR was especially applied for nucleic acid biomarker analysis. Although these constructed methods have been applied in wide range, they also showed some inherent shortcomings such as low sensitivity, large sample volume and complex operations. At present, many methods have been successfully constructed on the basis of DNA nanotechnology with the merits of high accuracy, rapid and simple operation for cancer biomarkers assay. In this review, we summarized the bioassay strategies based on DNA nanotechnology from the perspective of the analytical attributes for the first time and discussed and the feasibility of the reported strategies for clinical application in the future.

A signal conversion system using binding-induced strand displacement for disease biomarker assay.

Using the principle of binding-induced DNA strand displacement (BINSD), a DNAzyme-powered nanomachine biosensor for multiple biomarkers via magnetic beads-based signal conversion was designed. This sensor can convert multiple biomarker recognition into release of predesigned output nucleic acids tagged with streptavidin proteins (SA-DNA) for activation of DNA nanomachines. In general, we adopted complementary base pairing rules and affinity ligand specific recognition, and three types of signal conversion systems were constructed that realized universal, sensitive, accurate, and specific detection of multiple biomarkers. Taking the advantage of the strong anti-interference capability of magnetic separation, this strategy could be used for detection of various biomarkers in clinical practice.

Novel Single-Enzyme-Assisted Dual Recycle Amplification Strategy for Sensitive Photoelectrochemical MicroRNA Assay.

Herein, a novel single-enzyme-assisted dual recycle amplification strategy based on T7 exonuclease (T7 Exo) and a strand-displacement reaction (SDR) was designed to fabricate a photoelectrochemical (PEC) biosensor for sensitive microRNA-141 (miRNA-141) detection with the use of laminar bismuth tungstate (Bi2WO6) as photoactive material. Compared with a traditional enzyme-assisted dual recycle amplification strategy, the presented method could effectively refrain the enzyme interference reaction, reduce environmental sensitivity, and save cost. Here, hairpin DNA1 (H1) decorated on magnetic beads (MB) hybridized with target miRNA-141 to form an H1/miRNA-141 heteroduplex. With the introduction of hairpin DNA2 (H2)-labeled SiO2 (H2-SiO2), SDR was triggered between H2-SiO2 and H1, thus miRNA-141 was displaced from the H1/miRNA-141 heteroduplex and an H1/H2-SiO2 duplex was formed, realizing the reuse of the target. In the presence of T7 Exo, the H1/H2-SiO2 duplex was digested with the release of output DNA-SiO2. To enhance the target conversion rate, H1-MB was intactly released and cycled, which could initiate more T7 Exo digestion and free abundant output DNA-SiO2. Through such a process, a tiny miRNA-141 could induce substantial output DNA-SiO2, effectively improving the target amplification efficiency and detection sensitivity of a PEC biosensor. Furthermore, Bi2WO6 was modified on an electrode to provide a superior initial PEC signal due to its excellent electronic transformation capacity. With the introduction of output DNA-SiO2, the hairpin structure of H3 on the electrode was opened, making SiO2 close to the electrode surface, which significantly decreases the PEC signal. This work first established the PEC biosensor featuring a single-enzyme-assisted dual recycle amplification process for sensitive detection of biomarkers.

A Carbapenem-Based Off-On Fluorescent Probe for Specific Detection of Metallo-ß-Lactamase Activities.

Metallo-ß-lactamase is one of the major clinical threats because this ß-lactam-hydrolyzing enzyme confers significant resistance to most ß-lactam antibiotics, including carbapenems, among bacterial pathogens. Reported herein is a novel fluorogenic sensor for the specific detection of metallo-ß-lactamase activities. This carbapenem-based reagent exhibits excellent selectivity to metallo-ß-lactamase over other serine-ß-lactamases, including serine carbapenemases. The usefulness of this probe was further demonstrated in the rapid identification of metallo-ß-lactamase-expressing pathogenic bacteria.

[Ru(dcbpy)2 dppz]2+ /Fullerene Cosensitized PTB7-Th for Ultrasensitive Photoelectrochemical MicroRNA Assay.

A new cosensitization photoelectrochemical (PEC) strategy was established by using a donor-acceptor-type photoactive material, poly{4,8-bis[5-(2-ethylhexyl)thiophen-2-yl]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl-alt-3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophene-4,6-diyl} (PTB7-Th), as a signal indicator, which was cosensitized with bis(4,4'dicarboxyl-2,2'-bipyridyl)(4,5,9,14-tetraazabenzo[b]triphenylene)ruthenium(II) ([Ru(dcbpy)2 dppz]2+ ) embedded in the grooves of the DNA duplex and fullerene (nano-C60 ) immobilized on the surface of DNA nanoflowers for microRNA assay. [Ru(dcbpy)2 dppz]2+ and nano-C60 could effectively enhance the photoelectric conversion efficiency (PCE) of PTB7-Th as a result of well-matched energy levels among nano-C60 , [Ru(dcbpy)2 dppz]2+ and PTB7-Th, leading to a clearly enhanced photocurrent signal. Meanwhile, a target recycling magnification technique based on duplex-specific nuclease was applied in this work to obtain higher detection sensitivity. The proposed biosensor demonstrated excellent analytical properties within a linear detection range of 2.5 fm to 2.5 nm and a limit of detection down to 0.83 fm. Impressively, this cosensitization PEC strategy offers an effective and convenient avenue to significantly improve the PCE of a photoactive material, resulting in a remarkably improved photocurrent signal for ultrasensitive and highly accurate detection of various targets.

Specific Detection of Extended-Spectrum ß-Lactamase Activities with a Ratiometric Fluorescent Probe.

The dissemination of antimicrobial resistance around the world is one of the biggest threats to global public health. The acquisition and expression of extended-spectrum ß-lactamases (ESBLs) in pathogenic bacterial are mainly responsible for bacterial resistance to third-generation cephalosporins. Reported herein is a ratiometric fluorescent probe for the detection of the activity of ESBLs. This imaging reagent adopts the core structure of cefotaxime as an enzymatic recognition moiety, and exhibits excellent selectivity to ESBLs over other ß-lactamases. The specific activation of this sensor by ESBLs can lead to over 2500-fold changes in the fluorescent ratio, which is independent of the concentration of the probe and environmental conditions. Further experiments have demonstrated that this ratiometric fluorescent probe can distinguish bacteria with extended-spectrum antibiotic resistance from a group of clinically important pathogens within a short period of time.

Detection of Carbapenemase-Producing Organisms with a Carbapenem-Based Fluorogenic Probe.

Antibiotic resistance has become a major challenge to public health worldwide. This crisis is further aggravated by the increasing emergence of bacterial resistance to carbapenems, typically considered as the antibiotics of last resort, which is mainly due to the production of carbapenem-hydrolyzing carbapenemases in bacteria. Herein, the carbapenem-based fluorogenic probe CB-1 with an unprecedented enamine-BODIPY switch is developed for the detection of carbapenemase activity. This reagent is remarkably specific towards carbapenemases over other prevalent ß-lactamases. Furthermore, the efficient imaging of live clinically important carbapenemase-producing organisms (CPOs) with CB-1 demonstrates its potential for the rapid detection of antibiotic resistance and timely diagnosis of CPO infections.

Hypothermic oxygenated perfusion in liver transplantation: a meta-analysis of randomized controlled trials and matched studies.

BACKGROUND: Hypothermic oxygenated machine perfusion (HOPE) is a novel organ-preservation technology designed to optimize organ quality. However, the effects of HOPE on morbidity and mortality after liver transplantation remain unclear. This meta-analysis evaluated the potential benefits of HOPE in liver transplantation. MATERIALS AND METHODS: The Embase, Web of Science, PubMed, Cochrane Library, and Scopus databases were searched for articles published up to 15 June 2023 (updated on 12 August 2023). Mean differences (MDs), risk ratios (RRs), and 95% confidence intervals were calculated. RESULTS: Eleven studies encompassing five randomized controlled trials and six matched studies were included, with a total of 1000 patients. HOPE did not reduce the incidence of major postoperative complications (RR 0.80), primary non-function (PNF) (RR 0.54), reperfusion syndrome (RR 0.92), hepatic artery thrombosis (RR 0.92), renal replacement therapy (RR 0.98), length of hospital stay (MD, -1.38 days), 1-year recipient death (RR 0.67), or intensive care unit stay (MD, 0.19 days) after liver transplantation. HOPE reduced the incidence of biliary complications (RR 0.74), non-anastomotic biliary strictures (NAS) (RR 0.34), early allograft dysfunction (EAD) (RR 0.54), and acute rejection (RR 0.54). In addition, HOPE improved the retransplantation (RR 0.42) and 1-year graft loss rates (RR 0.38). CONCLUSIONS: Compared with static cold storage (SCS), HOPE can reduce the incidence of biliary complications, NAS, EAD, and acute rejection and retransplantation rate after liver transplantation and improve the 1-year graft loss rate. These findings suggest that HOPE, when compared to SCS, can contribute to minimizing complications and enhancing graft survival in liver transplantation. Further research is needed to investigate long-term outcomes and confirm the promising advantages of HOPE in liver transplantation settings.

Construction of a streptavidin-based dual-localized DNAzyme walker for disease biomarker detection.

A dual-localized DNAzyme walker (dlDW) was constructed by utilizing multiple split DNAzymes with probes, and their substrates are separately localized on streptavidin and AuNPs, serving as walking pedals and tracks, respectively. Based on dlDW, biosensing platform was successfully constructed and showed great potential application in clinical disease diagnosis.

Comparison of short-term outcomes of robotic versus open Pancreaticoduodenectomy: A Meta-Analysis of randomized controlled trials and Propensity-Score-Matched studies.

BACKGROUND: Robotic pancreaticoduodenectomy (RPD) is used more commonly, but this surge is mostly based on observational data. This meta-analysis aimed to compare the short-term outcomes between RPD and open pancreaticoduodenectomy (OPD) using data collected from randomized controlled trials (RCTs) and propensity score-matched (PSM) studies. MATERIALS AND METHODS: We searched PubMed, Cochrane Library, Embase, and Web of Science databases for RCTs and PSM studies comparing RPD and OPD. Risk ratios (RRs) and mean differences (MDs) with 95% confidence intervals (CIs) were calculated. RESULTS: Twenty-four studies, encompassing two RCTs and 22 PSM studies, were included, with a total of 9393 patients (RPD group: 3919 patients; OPD group: 5474 patients). Although RPD was associated with a longer operative time (MD, 61.61 min), patients may benefit from reduced blood loss (MD, -154.05 mL), shorter length of stay (MD, -1.60 d), lower blood transfusion rate (RR, 0.85), and wound infection rate (RR, 0.61). There were no significant differences observed in 30-day readmission (RR, 0.99), 90-day mortality (RR, 0.97), overall morbidity (RR, 0.88), major complications (RR, 1.01), reoperation (RR, 1.08), bile leak (RR, 1.01), chylous leak (RR, 0.98), postoperative pancreatic fistula (RR, 0.97), postpancreatectomy hemorrhage (RR, 1.15), delayed gastric emptying (RR, 0.88), number of harvested lymph nodes (MD, -0.12), and R0 resection (RR, 1.01) between the groups. CONCLUSIONS: Although some short-term outcomes were similar between RPD and OPD, RPD exhibited reduced intraoperative blood loss, shorter hospital stays, lower wound infection, and blood transfusion rates. In the future, RPD may become a safe and effective alternative to OPD.

Monitoring nucleic acid amplification process using a UiO-66-NH2-based fluorescent sensor.

Herein, we developed a nucleic acid amplification process monitoring scheme by the use of UiO-66-NH2, in which pyrophosphate ion (PPi) released from the amplification can competitively coordinate with Zr to weaken the ligand-to-metal charge transfer and cause fluorescence recovery, thus reflecting the amplification process. This is the first attempt at using a MOF for monitoring the nucleic acid amplification process.

Biomolecule-guided co-localization of intermolecular G-rich strands for the construction of a tetramolecular G-quadruplex sensing strategy.

We herein introduce the principle of proximity assay into tetramolecular G-quadruplexes guided by various biomolecules for the construction of a sensing strategy. Our strategy is based on the co-localization of intermolecular G-rich strands guided by a recognition event of a specific biomolecule to its corresponding affinity ligand. In such case, the local concentration among intermolecular strands is significantly increased to trigger the following self-assembly that served as the peroxidase-mimicking activity. This strategy is versatile, homogenous and adaptable to different types of biomolecules.

A new photoelectrochemical biosensor based on FeOOH and exonuclease III-aided dual recycling signal amplification for HPV-16 detection.

Herein, based on iron oxyhydroxide (FeOOH) as the photoactive material and exonuclease III (exo III)-aided dual recycling signal amplification, a new photoelectrochemical (PEC) biosensor was successfully developed for human papillomavirus-16 (HPV-16) detection with a wide linear range from 0.5 fM to 1 nM and a low detection limit of 0.17 fM.

Ultrasensitive photoelectrochemical microRNA biosensor based on doxorubicin sensitized graphitic carbon nitride assisted by a target-activated enzyme-free DNA walker.

Herein, a photoelectrochemical biosensor was successfully constructed on the basis of a sensitization strategy of doxorubicin sensitized graphitic carbon nitride for the ultrasensitive detection of microRNA-141 with the assistance of a target-activated enzyme-free DNA walker.

A novel "signal on" photoelectrochemical strategy based on dual functional hemin for microRNA assay.

In this work, a novel "signal on" photoelectrochemistry (PEC) biosensor was constructed with dual-functional hemin as a signal quencher and electronic mediator for ultrasensitive target microRNA-141 assay with the assistance of T7 exonuclease (Exo)-initiated target amplification technology.

A Self-Immobilizing and Fluorogenic Probe for ß-Lactamase Detection.

The spread of antibiotic resistance in pathogenic bacteria has become one of the major concerns to public health. Improved monitoring of drug resistance is of high importance for infectious disease control. One of the major mechanisms for bacteria to overcome treatment of antibiotics is the production of ß-lactamases, which are enzymes that hydrolyze the ß-lactam ring of the antibiotic. In this study, we have developed a self-immobilizing and fluorogenic probe for the detection of ß-lactamase activity. This fluorogenic reagent, upon activation by ß-lactamases, turns on a fluorescence signal and, more importantly, generates a covalent linkage to the target enzymes or the nearby proteins. The covalent labeling of enzymes was confirmed by SDS-PAGE analysis and MALDI-TOF mass spectrometry. The utility of this structurally simple probe was further confirmed by the fluorescent labeling of a range of ß-lactamase-expressing bacteria.