Search Results (116)

Staphylococcus aureus is the primary pathogen responsible for mastitis in dairy cows and foodborne illnesses, posing a significant threat to public health and food safety. Here, we developed an enhanced sensor based on solid-phase separation using gold-magnetic nanoparticles (Au@Fe₃O₄) and signal amplification via dendritic DNA nanostructures. The substrate chain was specifically immobilized using thiol–gold coordination, and a three-dimensional dendritic structure was constructed through sequential hybridization of DNAzymes, L chains, and Y chains, resulting in a 2.8-fold increase in initial fluorescence intensity. Upon specific cleavage of the substrate chain at the rA site by S. aureus DNA, the complex dissociates, resulting in fluorescence intensity decay. The fluorescence intensity is negatively correlated with the concentration of Staphylococcus aureus. After optimization, the biosensor maintains a detection limit of 1 CFU/mL within 3 min, with a linear range extended to 1–10⁷ CFU/mL (R² = 0.998) and recovery rates of 85.6–102.1%, significantly enhancing resistance to matrix interference. This provides an innovative solution for rapid on-site detection of foodborne pathogens. Full article

Lanthanide rare earth elements possess significant promise for material applications owing to their distinctive optical and magnetic characteristics, as well as their versatile coordination capabilities. This study introduced a lanthanide-functionalized magnetic nanocellulose composite (NNC@Fe₃O₄@La(OH)₃) for effective phosphorus/nitrogen (P/N) ligand separation. The hybrid material employs the adaptable coordination geometry and strong affinity for oxygen of La³⁺ ions to show enhanced DNA-binding capacity via multi-site coordination with phosphate backbones and bases. This study utilized cellulose as a carrier, which was modified through carboxylation and amination processes employing deep eutectic solvents (DES) and polyethyleneimine. Magnetic nanoparticles and La(OH)₃ were subsequently incorporated into the cellulose via in situ growth. NNC@Fe₃O₄@La(OH)₃ showed a specific surface area of 36.2 m²·g⁻¹ and a magnetic saturation intensity of 37 emu/g, facilitating the formation of ligands with accessible La³⁺ active sites, hence creating mesoporous interfaces that allow for fast separation. NNC@Fe₃O₄@La(OH)₃ showed a significant affinity for DNA, with adsorption capacities reaching 243 mg/g, mostly due to the multistage coordination binding of La³⁺ to the phosphate groups and bases of DNA. Simultaneously, kinetic experiments indicated that the binding process adhered to a pseudo-secondary kinetic model, predominantly dependent on chemisorption. This study developed a unique rare-earth coordination-driven functional hybrid material, which is highly significant for constructing selective separation platforms for P/N-containing ligands. Full article

DNA damage repair is a hallmark of any cancer growth, eventually leading to drug resistance and death. The poly ADP-ribose polymerase (PARP) enzyme is vital in repairing damaged DNA in normal and cancer cells with mutated DNA damage response (DDR) genes. Inhibitors of the PARP enzyme aid in chemotherapy, as shown by drug combinations such as Olaparib and Irinotecan in breast cancer treatment. However, the effect of Olaparib in colon cancer has not been studied extensively. Synthetic drugs have a significant limitation in cancer treatment due to drug resistance, leading to colon cancer relapse. Bioavailability of Olaparib and other PARP inhibitors is limited due to their hydrophobicity, which poses a significant challenge. These limitations and challenges can be addressed by encapsulating Olaparib in nanoparticles that could possibly increase the bioavailability of the drug at the site of action. New age nanoparticles, such as hybrid nanoparticles, provide superior quality in terms of design and circulatory time of the drug in the plasma. The side effects of Olaparib as a chemotherapeutic pave the way for exploring phytochemicals that may have similar effects. The combined impact of Olaparib and phytochemicals such as genistein, resveratrol and others in nano-encapsulated form can be explored in the treatment of colon cancer. Full article

Co-infections pose significant challenges not only clinically, but also in terms of simultaneous diagnoses. The development of sensitive, multiplexed analytical platforms is critical for accurately detecting viral co-infections, particularly in complex biological environments. In this study, we present a mass spectrometry (MS)-based detection strategy employing a target-triggered hybridization chain reaction (HCR) to amplify signals and in situ photocleavable mass tags (PMTs) for the simultaneous detection of multiple targets. Hairpin DNAs modified with PMTs and immobilized loop structures on magnetic particles (Loop@MPs) were engineered for each target, and their hybridization and amplification efficiency was validated using native polyacrylamide gel electrophoresis (PAGE) and laser desorption/ionization MS (LDI-MS), with silica@gold core–shell hybrid (SiAu) nanoparticles being employed as an internal standard to ensure quantitative reliability. The system exhibited excellent sensitivity, with a detection limit of 415.12 amol for the hepatitis B virus (HBV) target and a dynamic range spanning from 1 fmol to 100 pmol. Quantitative analysis in fetal bovine serum confirmed high accuracy and precision, even under low-abundance conditions. Moreover, the system successfully and simultaneously detected multiple targets, i.e., HBV, human immunodeficiency virus (HIV), and hepatitis C virus (HCV), mixed in various ratios, demonstrating clear PMT signals for each. These findings establish our approach as a robust and reliable platform for ultrasensitive multiplexed detection, with strong potential for clinical and biomedical research. Full article

Enzymes, as nature’s precision biocatalysts, hold transformative potential across industrial, environmental, and biomedical sectors. However, their instability, solvent sensitivity, and limited reusability in their free form necessitate advanced immobilization strategies to enhance their robustness and scalability. This review critically examines cutting-edge advancements in enzyme immobilization, focusing on the integration of artificial intelligence (AI), novel nanomaterials, and dynamic carrier systems to overcome the traditional limitations of mass transfer, enzyme leakage, and cost inefficiency. Key innovations such as metal–organic frameworks (MOFs), magnetic nanoparticles, self-healing hydrogels, and 3D-printed scaffolds are highlighted for their ability to optimize enzyme orientation, stability, and catalytic efficiency under extreme conditions. Moreover, AI-driven predictive modeling and machine learning emerge as pivotal tools for rationalizing nanomaterial synthesis, multi-enzyme cascade design, and toxicity assessment, while microfluidic systems enable precise biocatalyst fabrication. This review also explores emerging carrier-free strategies, including cross-linked enzyme aggregates (CLEAs) and DNA-directed immobilization, which minimize diffusion barriers and enhance substrate affinity. Despite progress, challenges persist in regards to eco-friendly nanomaterial production, industrial scalability, and real-world application viability. Future directions emphasize sustainable hybrid material design, AI-aided lifecycle assessments, and interdisciplinary synergies between synthetic biology, nanotechnology, and data analytics. By connecting laboratory innovation with industrial needs, this work provides a forward-thinking framework to harness immobilized enzymes for achieving global sustainability goals, particularly in bioremediation, bioenergy, and precision medicine. Full article

Hydrogels are three-dimensional network structures composed of hydrophilic polymers that can swell in water and are very similar to soft tissues such as connective tissue or the extracellular matrix. DNA hydrogels are particularly notable for biomedical applications due to their high biocompatibility, physiological stability, molecular recognition, biodegradability, easy functionalization, and low immunogenicity. Based on these advantages, stimuli-responsive DNA hydrogels that have the property of reversibly changing their structure in response to various microenvironments or molecules are attracting attention as smart nanomaterials that can be applied to biosensing and material transfer, such as in the case of cells and drugs. As DNA nanotechnology advances, DNA can be hybridized with a variety of nanomaterials, from inorganic nanomaterials such as gold nanoparticles (AuNPs) and quantum dots (QDs) to synthetic polymers such as polyacrylamide (PAAm) and poly(N-isopropylacrylamide) (pNIPAM). These hybrid structures exhibit various optical and chemical properties. This review discusses recent advances and remaining challenges in biomedical applications of stimuli-responsive smart DNA hydrogel-based systems. It also highlights various types of hybridized DNA hydrogel, explores various response mechanism strategies of stimuli-responsive DNA hydrogel, and provides insights and prospects for biomedical applications such as biosensing and drug delivery. Full article

Immunoassays using surface-enhanced Raman scattering (SERS) are prosperous in disease diagnosis due to their excellent multiplexing ability, high sensitivity, and large dynamic range. Given the recent advancements in SERS immunoassays, this work provides a comprehensive overview, from fundamental principles to practical applications. An mRNA sensor utilizing Raman spectroscopy is a detection method that leverages the unique vibrational characteristics of mRNA molecules to identify and quantify their presence in a sample, often achieved through a technique called SERS, where specially designed nanoparticles amplify the Raman signal, allowing for the highly sensitive detection of even small amounts of mRNA. This review analyzes SERS assays used to detect RNA biomarkers, which show promise in cancer diagnostics and are being actively studied clinically. To selectively detect a specific mRNA sequence, a probe molecule (e.g., a DNA oligonucleotide complementary to the target mRNA) is attached to the SERS substrate, allowing the target mRNA to hybridize and generate a detectable Raman signal upon binding. Thus, the discussion includes proposals to enhance SERS immunoassay performance, along with future challenges and perspectives, offering concise, valid guidelines for platform selection based on application. Full article

Background: Lipid nanoparticles (LNPs) and polyethyleneimine (PEI) have independently been used for DNA complexation and delivery. However, non-ideal gene delivery efficiency and toxicity have hindered their clinical translation. We developed DNA-PEI-LNPs as a strategy to overcome these limitations and enhance DNA delivery and transgene expression. Methods: Three microfluidic mixing protocols were evaluated: (i) LNPs without PEI, (ii) a single-step process incorporating PEI in the organic phase, and (iii) a two-step process with DNA pre-complexed with PEI before LNP incorporation. The influence of DNA/PEI ratios (1:1, 1:2, 1:3) and DNA/lipid ratios (1:10, 1:40) on particle properties and delivery efficiency was examined. Results: In luciferase formulations, higher DNA/lipid ratios (1:40) produced smaller particles (136 nm vs. 188 nm) with improved cellular uptake (77% vs. 50%). The two-step method with higher DNA/PEI ratios improved transfection efficiency, with LNP-Luc/PEI 1:3 (40) achieving ~1.9 × 10⁶ relative light units (RLU) in luciferase expression. In green fluorescent protein (GFP) studies, LNP-GFP/PEI 1:3 (40) showed ~23.8% GFP-positive cells, nearly twofold higher than LNP-GFP (40) at ~12.6%. Conclusions: These results demonstrate the capability of microfluidic-prepared DNA-PEI-LNPs to improve DNA delivery and transgene expression through optimized formulation strategies and selection of appropriate preparation methods. Full article

Abnormal expression of miRNAs is associated with the occurrence and progression of cancer and other diseases, making miRNAs essential biomarkers for disease diagnosis and prognosis. However, the intrinsic properties of miRNAs, such as short length, low abundance, and high sequence homology, represent great challenges for fast and accurate miRNA detection in clinics. Herein, we developed a novel hybridization chain reaction (HCR)-based electrochemical miRNAs chip (e-miRchip), featured with gold nanostructured electrodes (GNEs) and silver nanoparticle reporters (AgNRs), for sensitive and multiplexed miRNA detection. AgNRs were synthesized and applied on the e-miRchip to generate strong redox signals in the presence of miRNA. The stem–loop capture probe was covalently immobilized on the GNEs, and was opened upon miRNA hybridization to consequently trigger the HCR for signal amplification. The multiple long-repeated DNA helix generated by HCR provides the binding sites for the AgNRs, contributing to the amplification of the electrochemical signals of miRNA hybridization. To optimize the detection sensitivity, GNEs with three distinct structures were electroplated, in which flower-like GNEs were found to be the best electrode morphology for miRNAs analysis. Under optimal conditions, the HCR-based e-miRchip showed an excellent detection performance with an LOD of 0.9 fM and a linear detection range from 1 fM to 10 pM. Moreover, this HCR-based e-miRchip platform was able to effectively distinguish miRNAs from the one- or two-base mismatches. This HCR-based e-miRchip holds great potential as a highly efficient and promising miRNA detection platform for the diagnosis and prognosis of cancer and other diseases in the future. Full article

Modernization of existing methods for the delivery of mRNA is vital in advanced therapeutics. Traditionally, mRNA has faced obstacles of poor stability due to enzymatic degradation. This work examines cutting-edge formulation and emerging techniques for safer delivery of mRNA vaccines. Inspired by the success of lipid nanoparticles (LNP) in delivering mRNA vaccines for COVID-19, a variety of other formulations have been developed to deliver mRNA vaccines for diverse infections. The meritorious features of nanoparticle-based mRNA delivery strategies, including LNP, polymeric, dendrimers, polysaccharide-based, peptide-derived, carbon and metal-based, DNA nanostructures, hybrid, and extracellular vesicles, have been examined. The impact of these delivery platforms on mRNA vaccine delivery efficacy, protection from enzymatic degradation, cellular uptake, controlled release, and immunogenicity has been discussed in detail. Even with significant developments, there are certain limitations to overcome, including toxicity concerns, limited information about immune pathways, the need to maintain a cold chain, and the necessity of optimizing administration methods. Continuous innovation is essential for improving delivery systems for mRNA vaccines. Future research directions have been proposed to address the existing challenges in mRNA delivery and to expand their potential prophylactic and therapeutic application. Full article

Infectious laryngotracheitis virus (ILTV), a DNA virus classified as Gallid alphaherpesvirus 1, causes a highly contagious respiratory disease in chickens, leading to significant economic losses and health risks for the poultry industry. The rapid detection of ILTV is essential to control its spread and prevent outbreaks. Traditional diagnostic methods like PCR are costly, require specialized personnel, and delay response efforts. To address this, we developed a point-of-care diagnostic test combining loop-mediated isothermal amplification (LAMP) with DNA nanoprobes on respiratory swabs. LAMP targets the ILTV-glycoprotein E (gE) gene, enabling rapid nucleic acid amplification at 65 °C without extraction, making it suitable for on-site detection. DNA nanoprobes provide a colorimetric readout visible to the naked eye. Gold nanoparticles drive this readout, as their red color, based on localized surface plasmon resonance, persists in the presence of ILTV DNA through DNA-DNA hybridization, ensuring reliable detection. The assay achieved 100% sensitivity and specificity for ILTV-gE, with a detection limit of 200 copies per reaction, allowing for the early identification of infections. The results are available within 45 min, enabling prompt measures to control ILTV spread. Cost-effective and user-friendly, this method enhances disease management and biosecurity in poultry farms. Full article

Background/Objectives: Aberrant hypermethylation in the promoter regions of tumor suppressor genes facilitates the pathogenesis and progression of cancer. Therefore, inhibitors targeting DNA methyltransferase (DNMT) have been tested in clinical studies. However, the current monotherapy of DNMT inhibitors shows limited efficacy. Furthermore, the mechanism of action of DNMT inhibitors is DNA replication-dependent. To address these limitations, we developed a novel core–shell-type “epigenetics control (EpC) nanocarrier” that encapsulated decitabine (5-aza-dC) in the PLGA core nanoparticle and hybridized TET1 gene-encoding pDNA on the lipid shell surface. This study aimed to evaluate whether the dual delivery of DNMT inhibitors and pDNA of TET1 could synergistically enhance tumor suppressor gene expression and induce cell cycle arrest and/or apoptosis in cancer cells. Herein, we demonstrate the potential of the EpC carrier in HCT116 human colon cancer cells to upregulate tumor suppressor gene expression and rapidly achieve cell cycle arrest. Methods: PLGA core nanoparticles were prepared by the W/O/W double emulsion method. The formation of core–shell nanoparticles and complexation with pDNA were investigated and optimized by dynamic light scattering, zeta potential measurement, and agarose gel electrophoresis. The cellular uptake and transfection efficiency were measured by confocal laser scanning microscopy and a luciferase assay, respectively. The expression of p53 protein was detected by Western blotting. The anti-tumor effects of the EpC nanocarrier were evaluated by cell cycle analysis and an apoptosis assay. Results: The EpC nanocarrier delivered the DNMT inhibitor and TET gene-encoding pDNA into HCT116 cells. It promoted the expression of the tumor suppressor protein p53 and induced rapid cell cycle arrest in the G2/M phase in HCT116 cells. Conclusions: Our findings suggest that the dual-targeting of DNMT and TET enzymes effectively repairs aberrant DNA methylation and induces growth arrest in cancer cells, and the dual-targeting strategy may contribute to the advancement of epigenetic cancer therapy. Full article

MicroRNA122 (miR-122) is a microRNA that is highly expressed in hepatocytes and has been identified as a prospective therapeutic target and biomarker for liver injury. An expanding body of research has demonstrated that miR-122 is a critical regulator in both the initiation and progression of a wide range of liver diseases. Traditional methods for detecting miR-122 mainly include Northern blotting and qRT-PCR, but they are technically complex and cumbersome, requiring expensive instruments and high technical requirements. In this paper, we present a novel rapid testing method utilizing a lateral flow nucleic acid biosensor (LFNAB) for the sensitive and time-efficient detection of miR-122. This approach offers several advantages, including a high specificity for miR-122, the ability to detect low concentrations of the target molecule, and a significantly reduced testing time compared to conventional detection methods. In this study, a thiol-modified single-stranded detection DNA probe (Det-DNA), a biotinylated single-stranded capture DNA probe (Cap-DNA), and a biotinylated single-stranded control DNA probe (Con-DNA) are used to construct the LFNAB. A gold nanoparticle (AuNP) is a colored tag, which is used to label the Det-DNA probe. The principle of detecting miR-122 is based on dual DNA-miRNA hybridization reactions on the LFNAB to form sandwich-type AuNP-Det-DNA-miR-122-Cap-DNA complexes, which are captured on the test area of LFNAB for visualization and quantification. After systematic optimization of conditions of experiment, the response of LFNAB was highly linear within the scope of 0 pM-100 pM miR-122, and the detection limit in 15 min was 3.90 pM. The use of LFNAB to detect miR-122 in serum and fingertip blood has yielded satisfactory results. This successful application indicates the effectiveness of LFNAB in detecting miR-122 in both serum and fingertip blood samples, showcasing its potential utility in clinical and research settings for assessing miR-122 levels in different biological samples. Full article

Due to the price and demand of Ophiocordyceps sinensis having increased dramatically, adulteration with other fungi is a common problem. Thus, a reliable method of authentic O. sinensis identification is essential. In the present work, a rapid DNA extraction and double-tailed recombinase polymerase amplification (RPA) coupled with nucleic acid hybridization lateral flow strip (NAH-LFS) was developed to distinguish authentic O. sinensis ingredients from other fungi substitutes. In the presence of O. sinensis, the RPA amplicons with two ssDNA tails in the opposite ends, which could simultaneously bind with the SH-probes on gold nanoparticles (AuNPs) and capture the probe on the test line, formed visible red bands. RPA combined with NAH-LFS can efficiently detect O. sinensis DNA down to 1.4 ng/μL; meanwhile, the specificity test validated no cross reaction with common adulterants, including Cordyceps gunnii, Cordyceps cicadae, Cordyceps militaris, yungui Cordyceps, and Ophiocordyceps nutans. The whole RPA-NAH-LFS could be completed within 16 min. The RPA-NAH-LFS results in detecting 20 commercial O. sinensis samples are consistent with PCR-AGE and RT-PCR, confirming the feasibility of the RPA-NAH-LFS method. In conclusion, these results are expected to facilitate the application of RPA-NAH-LFS in the authentication detection of O. sinensis materials, providing a convenient and efficient method for O. sinensis quality control. Full article

Catalytic DNA has gained significant attention in recent decades as a highly efficient and tunable catalyst, thanks to its flexible structures, exceptional specificity, and ease of optimization. Despite being composed of just four monomers, DNA’s complex conformational intricacies enable a wide range of nuanced functions, including scaffolding, electrocatalysis, enantioselectivity, and mechano-electro spin coupling. DNA catalysts, ranging from traditional DNAzymes to innovative DNAzyme hybrids, highlight the remarkable potential of DNA in catalysis. Recent advancements in spectroscopic techniques have deepened our mechanistic understanding of catalytic DNA, paving the way for rational structural optimization. This review will summarize the latest studies on the performance and optimization of traditional DNAzymes and provide an in-depth analysis of DNAzyme hybrid catalysts and their unique and promising properties. Full article