Search Results (190)

The distinct electronic and optical properties of gold nanoparticles (NPs) have made them innovative assets for biomolecular sensing. This review outlines the various gold nanoparticle-based biosensing techniques centred on biomolecule detection and signal relay. We discussed the physical, chemical (Turkevich, Brust, seed-mediated growth, and digestive ripening) and biological syntheses involving bacteria, fungi, and plant extracts. Also discussed were the various ways these techniques affect the shape and functionality of the nanoparticles. Detection techniques are typically classified as the following: colourimetric, fluorescence-based, electrochemical, and surface plasmon resonance (SPR). Colourimetric assays enable visual detection of proteins and oligonucleotides by monitoring gold NP aggregation, while molecular beacons enable precise fluorescent-based detection. Quantitative detection of small molecules and gold NPs can be performed using electrochemical sensing, and biomolecular interactions can be analysed in real time using SPR. With the review focusing on the integration of gold NPs with microfluidics and wearable sensors, this synthesis aims to support the design of more practical, real-world applications of the described techniques. Full article

Poly(amidoamine) (PAMAM) dendrimers are widely recognized as versatile nanocarriers due to their tunable architecture and ability to associate with bioactive molecules. In this study, generation 3 PAMAM dendrimers functionalized with triphenylphosphonium (TPP) were employed to investigate the association of structurally related phenolic compounds—caffeic acid, p-coumaric acid, and cinnamic acid—through either covalent conjugation or non-covalent encapsulation. Physicochemical characterization by NMR, dynamic light scattering, and zeta potential measurements revealed the formation of supramolecular aggregates rather than isolated dendrimer units, with hydrodynamic diameters ranging from 127 to 260 nm and positive surface charge across all formulations. Encapsulation efficiencies determined by HPLC reached 93.8% for caffeic acid, 78.9% for p-coumaric acid, and 71% for cinnamic acid, indicating differential association behavior. Molecular dynamics simulations over 1 μs supported these findings, showing stronger and more stable interactions for polar antioxidants, particularly caffeic acid, driven by hydrogen bonding and electrostatic interactions, while cinnamic acid displayed preferential binding in more hydrophobic dendrimer regions. Radical scavenging assays (DPPH• and ABTS•+) demonstrated that all formulations retained antioxidant capacity, although dendrimer association modulated scavenging kinetics. In cellular assays under oxidative stress, free caffeic acid exhibited the strongest immediate reduction of intracellular reactive oxygen species, whereas dendrimer-associated systems showed reduced but significant activity, consistent with decreased solvent accessibility and slower release predicted by simulations. Overall, these results highlight a trade-off between molecular retention and immediate biological efficacy, demonstrating that the mode of association governs antioxidant accessibility and performance. This combined experimental and computational approach provides a mechanistic framework for the rational design of dendrimer-based delivery systems aimed at balancing stability and functional activity. Full article

Background: Nanopore sequencing produces ionic current signals that are sensitive to chemical modifications in DNA and RNA molecules. However, accurate modification detection remains challenging due to limited labeled data and variability across experimental conditions. Methods: We present a scalable unsupervised framework for modification discovery that learns reference signal distributions from unmodified sequences using a CNN–Transformer variational autoencoder (VAE). The model is trained on large-scale data via streaming sampling and k-mer-aware soft balancing to ensure robust signal representation. At inference, candidate nucleotides are scored using the VAE reconstruction error, and read-level signals are aggregated to produce site-level modification evidence. Results: On controlled DNA oligonucleotide datasets, models trained on unmodified sequences achieve strong discrimination when evaluated on modified oligos. In contrast, performance decreases in cell line samples when models trained on unmodified whole-genome-amplified (WGA) DNA and in vitro-transcribed (IVT) RNA are evaluated on natively modified (5mC/m6A) data, reflecting the impacts of biological noise and heterogeneity. Despite reduced classification accuracy, site-level anomaly score profiles exhibit peak-like patterns that correspond to known modification-enriched regions. Conclusions: These findings demonstrate the feasibility of large-scale unsupervised reference modeling for de novo modification detection, while underscoring the challenges in translating models built from synthetic oligo datasets into robust genome-wide modification detection. Full article

Background/Objectives: Circulating tumour DNA (ctDNA) assays enable non-invasive assessment of tumour burden and treatment response in oncology. However, quantitative ctDNA outputs (such as variant allele frequency, tumour fraction, and aggregate burden scores) remain difficult to interpret and compare across platforms. This evidence-mapping review evaluates current quantitative reporting approaches in pancreatic ductal adenocarcinoma (PDAC) and examines the potential role of KRAS mutant ctDNA as a biologically grounded reference metric. Methods: A systematic literature search was conducted across PubMed/MEDLINE and Scopus to identify studies reporting quantitative ctDNA metrics in PDAC. Eligible studies included those measuring plasma KRAS mutations and/or reporting variant allele frequency, tumour fraction, or multi-locus aggregate metrics. Additional relevant primary studies identified through broader manual searching of PubMed were assessed against the same prespecified eligibility and classification criteria before inclusion. Data were synthesised narratively, focusing on reporting frameworks, units of measurement, assay characteristics, and the interpretability of quantitative outputs across platforms. Results: Substantial heterogeneity was observed in ctDNA quantification methods and reporting standards. Ratio-based metrics such as variant allele frequency and tumour fraction were commonly used but varied according to assay design, plasma input volume, and background cell-free DNA levels. Few studies reported absolute mutant molecule counts per unit volume. Given that approximately 90–95% of PDACs harbour truncal activating KRAS mutations, plasma KRAS was consistently represented across platforms and demonstrated potential as a shared quantitative anchor. Limited standardisation was noted in distinguishing detectability from quantifiability based on sampling depth and counting statistics. Conclusions: Current ctDNA reporting in PDAC lacks a shared quantitative reference, limiting cross-study comparability. Reporting KRAS mutant molecules per millilitre and adopting an assay-agnostic framework distinguishing detection from quantification may improve interpretability, support harmonisation across platforms, and facilitate cumulative learning in pancreatic cancer ctDNA research. Full article

Up to now, most hydrogel-related studies have been devoted to the preparation of drug-containing macromolecular gels via the introduction of polymer matrices, together with the clarification of their assembly mechanisms and biomedical applications. In contrast, studies concerning the design of small-molecule gel systems remain relatively limited. As gel research progresses, drug small-molecule hydrogels have attracted growing interest for formulation development. This study investigated whether designing a small-molecule hydrogel could serve as an effective solubilization approach for sulindac (SUL)—a nonsteroidal anti-inflammatory drug clinically restricted by its poor aqueous solubility. Then, a SUL small-molecule hydrogel was prepared by straightforward mixing of SUL with biologically safe meglumine (MEG) in a minimal volume of deionized water, which exhibited a characteristic three-dimensional network structure and favorable viscoelastic properties. The characterization and simulation results indicated that the hydrogel formation was contingent upon the SUL-MEG miscibility, dissolution-aggregation equilibrium and intermolecular self-assembly. Consequently, the resulting SUL-MEG hydrogel exhibited 546 times higher solubility compared to the pure SUL. Meanwhile, the SUL-MEG hydrogel demonstrated superior release kinetics and supersaturation capacity, characterized by rapid attainment of peak concentrations and sustained supersaturated release. These enhanced performances were attributed to the high-energy state of the hydrogel itself and the molecular complexation between SUL and MEG. In conclusion, this study presents a feasible formulation strategy for overcoming the poor water solubility of insoluble drugs through the development of small-molecule hydrogel formulations. Full article

Background/Objectives: Alzheimer’s disease (AD) is characterized by progressive neurodegeneration driven by interconnected mechanisms, including oxidative stress, mitochondrial dysfunction, neuroinflammation, synaptic impairment, and abnormal protein aggregation. MicroRNAs (miRNAs) have emerged as post-transcriptional regulators of these complex pathways; however, efficient delivery remains a major limitation. Small extracellular vesicles (sEVs) have been proposed as biologically compatible carriers for miRNA delivery. Methods: In this study, milk-derived sEVs were isolated, characterized, and loaded with microRNA-137-5p (miR-137-5p). Their effects were evaluated in an amyloid-β (Aβ)-induced in vitro AD model using SH-SY5Y human neuroblastoma cells. Oxidative stress markers, including reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), lactate dehydrogenase (LDH), and glutathione peroxidase 1 (GPX1), were assessed. Inflammation- and neuroprotection-related gene expression analyses included intercellular adhesion molecule 1 (ICAM1), tumor necrosis factor alpha (TNF-α), and brain-derived neurotrophic factor (BDNF). Cytoskeletal injury was evaluated using neurofilament light chain (NfL). Mitochondrial stress markers included cytochrome c (Cyt-c), 8-hydroxy-2′-deoxyguanosine (8-OHdG), PTEN-induced kinase 1 (PINK1), dynamin-1-like protein (DNM1L), and mitochondrial transcription factor A (TFAM). Synaptic and extracellular matrix-associated proteins, including complexin-2 (CPLX2), SPARC-related modular calcium-binding protein 1 (SMOC1), and receptor tyrosine kinase-like orphan receptor 1 (ROR1), as well as AD-related biomarkers, including total tau, phosphorylated tau at threonine 181 (pTau-181), phosphorylated tau at threonine 217 (pTau-217), and amyloid-β 1–40 (Aβ1–40), were evaluated using molecular and biochemical approaches. Results: Aβ exposure was associated with increased oxidative stress, inflammatory activation, mitochondrial and cytoskeletal alterations, synaptic-related disturbances, and elevations in tau- and amyloid-associated proteins. Treatment with unloaded sEVs was associated with partial modulation of several parameters, whereas miR-137-5p-loaded sEVs were consistently associated with normalization of multiple pathological markers toward control levels. Conclusions: These findings indicate that miR-137-5p-enriched sEVs may represent a useful experimental platform for multi-target modulation of AD-related cellular alterations. Further mechanistic and in vivo studies are required to clarify translational relevance. Full article

Lipids are a diverse group of hydrophobic molecules including fats, oils, phospholipids, and steroids that are vital for numerous biological functions including energy storage, cellular structure, and signaling whose composition and metabolism undergo profound transformations with age. These age-related shifts due to increased lipid peroxidation, disrupted cholesterol homeostasis, and altered membrane phospholipid content, actively contribute to progressive loss in cellular homeostasis and pathogenesis of major age-related diseases. This review explores the critical role of lipids: as master regulators of cellular signaling pathways, and as key drivers of chronic inflammation and metabolic dysfunction. Dysregulated lipid metabolism is central to cardiovascular disease which is driven by altered myocardial energy substrate utilization and lipoprotein dynamics. In neurodegenerative disorders like Alzheimer’s and Parkinson’s disease, disruptions in ceramide, cholesterol, and specialized pro-resolving lipid mediators fuel neuroinflammation and protein aggregation. Furthermore, we explore the dual role of dietary lipids, which can either exacerbate or mitigate age-related decline, highlighting the potential of personalized nutritional approaches and lipid-targeting therapeutics. By integrating the mechanisms of lipid signaling, inflammation, and metabolic regulation, this analysis highlights that lipids are not merely passive structural components but active drivers of the aging process, positioning lipid metabolism as a promising frontier for interventions aimed at promoting health span and combating age-related disease. Full article

Valsartan (Val)—a lipophilic non-peptide angiotensin II type 1 receptor antagonist—is highly effective against hypertension and displaying limited solubility in water (3.08 μg/mL), thereby resulting in low oral bioavailability (23%). The limited water solubility of antihypertensive drugs can pose a challenge, particularly for rapid and precise administration. Herein, we synthesize and characterize valsartan-containing silver nanoparticles (Val-AgNPs) using Mangifera indica leaf extracts. The physicochemical, structural, thermal, and pharmacological properties of these nano-conjugates were established through various analytical and structural tools. The spectral shifts in both UV-visible and FTIR analyses indicate a successful interaction between the valsartan molecule and the silver nanoparticles. The resulting nano-conjugates are spherical and within the size range of 30–60 nm as revealed in scanning electron-EDS and atomic force micrographs. The log-normal distribution of valsartan-loaded nanoparticles, with a size range of 30 to 60 nm and a mode of 54 nm, indicates a narrow, monodisperse, and highly uniform particle size distribution. This is a favorable characteristic for drug delivery systems, as it leads to enhanced bioavailability and a consistent performance. Dynamic Light Scattering (DLS) analysis of the Val-AgNPs indicates a polydisperse sample with a tendency toward aggregation, resulting in larger effective sizes in the suspension compared to individual nanoparticles. The accompanying decrease in zeta potential (to −19.5 mV) and conductivity further supports the idea that the surface chemistry and stability of the nanoparticles changed after conjugation. Differential scanning calorimetry (DSC) demonstrated the melting onset of the valsartan component at 113.99 °C. The size-dependent densification of the silver nanoparticles at 286.24 °C correspond to a size range of 40–60 nm, showing a significant melting point depression compared to bulk silver due to nanoscale effects. The shift in Rf for pure valsartan to Val-AgNPs suggests that the interaction with the AgNPs alters the compound’s overall polarity and/or its interaction with the stationary phase, complimented in HPTLC and HPLC analysis. The stability and offloading behavior of Val-AgNPs was observed at pH 6–10 and in 40% and 80% MeOH. In addition, Val-AgNPs did not reveal hemolysis or significant alterations in blood cell indices, confirming the safety of the nano-conjugates for biological application. In conclusion, these findings provide a comprehensive characterization of Val-AgNPs, highlighting their potential for improved drug delivery applications. Full article

Snake venoms are rich sources of bioactive molecules that modulate hemostasis and, among these, anticoagulant snake venom phospholipases A₂ (sPLA₂) are found in a range of snake venoms. Crotoxin (CTX), from the Crotalus durissus rattlesnake, is a heterodimeric PLA₂ complex, and literature has reported its mechanisms in anticoagulant activity. The present review revisits the biological roles of anticoagulant sPLA₂ and critically examines evidence on CTX in hemostatic regulation, aiming to clarify its mechanisms and therapeutic promise. CTX exerts anticoagulant activity via enzymatic hydrolysis of procoagulant phospholipids and direct interaction with coagulation factors, disrupting key complex assembly. It also counteracts inflammation-induced coagulation by modulating leukocyte- and endothelial-derived mediators, restoring balance among anticoagulant, procoagulant, and fibrinolytic pathways. Effects on platelet function appear comparatively modest, ranging from less potent pro-aggregatory activity to negligible aggregation. The dual anticoagulant and anti-inflammatory properties of CTX highlight its potential as a model for novel antithrombotic agents in hypercoagulable and inflammation-driven disorders, despite toxicological concerns that necessitate cautious pharmacological exploration. Full article

Microcystis aeruginosa formed in natural water bodies grow in aggregate particles, while Microcystis aeruginosa commonly used in scientific research grow in a single-celled discrete state during cultivation. To elucidate the factors and mechanisms of Microcystis aeruginosa entering the “cell-aggregate” survival state in the natural environment, we focused on studying the influence of biological factors in their living environment (coexisting bacteria) on the aggregation behavior and growth characteristics of Microcystis aeruginosa. The bacterial strain A20, which can promote the aggregative behavior of Microcystis aeruginosa, was isolated from the water of Taihu Lake, where a cyanobacterial bloom broke out. A20 was identified as Priestia megaterium. Results showed that A20 could significantly drive Microcystis aeruginosa to form sac-like aggregate structures and promote the increase of aggregate particle size from 3–7 μm to 180 μm. The coexistence of bacteria and algae exhibited a dynamic stage adaptation strategy, with A20 promoting the transition of Microcystis aeruginosa from “high-chlorophyll, low-photochemical efficiency growth and proliferation” to “stable survival and maintenance of chlorophyll and photochemical efficiency in fluctuating changes” adaptation strategies. The coexistence of bacteria and algae significantly intensified the release of humic acid-like, fulvic acid-like, and protein-like substances from Microcystis aeruginosa, with the most significant increase in small-molecule fulvic acid-like substances. This is probably related to the endogenous metabolic stress response of Microcystis aeruginosa during A20 invasion, as well as the utilization and transformation of autotrophic Microcystis aeruginosa metabolites by heterotrophic bacteria A20. This study contributes to the study of microbial interactions underlying bloom outbreaks and can be useful for developing community-targeted algal control technologies. Full article

Grape pomace is the principal by-product of the winemaking industry, with an estimated global production of 14 million tonnes annually. Traditional livestock systems often incorporate local agroindustrial by-products into ruminant diets, and grape pomace is particularly notable for its high concentrations of bioactive compounds. These grape-derived molecules may exert beneficial effects on animal oxidative balance, biochemical status and productive performance, offering an environmentally and economically sustainable alternative to conventional feed ingredients that may be incorporated into the milk produced. This study evaluated the impact of incorporating varying inclusion levels (0, 5, 10 and 15% DM) of ensiled white grape pomace (WGP) into isoenergetic and isoproteic diets on the nutritional and technological characteristics of goat milk. Eighty-eight Murciano-Granadina dairy goats were selected and allocated into eight homogeneous batches (n = 11 per batch) based on physiological traits. Following a pre-experimental sampling, each diet was randomly assigned to two batches, and the feeding trial lasted eight weeks. After a two-week dietary adaptation period, four biweekly samplings were conducted to obtain representative bulk tank milk samples from each batch. Milk samples were analysed for gross composition, pH, mineral profile, fatty acid composition, coagulation properties, colorimetric parameters and antioxidant capacity. WGP consumption significantly increased milk fat content, improved the lipid profile from a human health perspective, accelerated curd aggregation and elevated the yellowness index. Moreover, notable changes were observed in the antioxidant activity of the milk. Despite these effects, the overall composition of the milk remained largely unchanged, which is a key factor in preserving its technological properties. Nevertheless, the final product demonstrated enhanced biological quality, reinforcing its value as a functional food for human consumption. Full article

The study of the conformational stability of protein layers at the interface between gold surfaces and lipid membranes is crucial for determining the biological activity of these systems and understanding their interactions. The surfaces differ significantly in hardness: gold is a rigid substrate, while the POPC/POPS liposome layer is highly flexible. A quartz crystal microbalance with dissipation (QCM-D) monitoring method and multi-parametric surface plasmon resonance (MP-SPR) were used to determine the adsorption efficiency of lysozymes, the level of layer hydration, and changes occurring within the secondary structure and the thickness of the formed protein layer. In both methods, lysozyme adsorption on the gold surface was more effective at pH 4.0 than at pH 7.4. The lysozyme adsorption efficiency on the surface of the lipid layer was the same for both measurement conditions. In contrast, the affinity of lysozyme molecules to the lipid surface was higher than that of the gold surface. The composition of the secondary structure of lysozymes was monitored using the FT-IR method. Deconvolution of the Amide I band confirms the existence of different mechanisms underlying lysozyme molecule immobilization depending on the type of adsorption surface. Along with the change in the surface, there is a transition from the dominance of electrostatic to hydrophobic interactions, which significantly affects the structure of the interphase layer. High content of random structures on the lipid surface is evident, while, in the case of the gold surface, there is a decrease in random structures and the presence of antiparallel β-sheets. Interaction with the surface induces the transition of amyloidogenic domains of the protein to conformations, which are particularly susceptible to aggregation, consequently leading to oligomerization. Full article

Low-complexity domains (LCDs) are protein regions characterized by a simple amino acid composition and low sequence complexity, as they are typically composed of repeats or a limited set of a few amino acids. Historically dismissed as “garbage sequences”, these regions are now acknowledged as critical functional elements. This review systematically explores the structural characteristics, biological functions, pathological roles, and research methodologies associated with LCDs. Structurally, LCDs are marked by intrinsic disorder and conformational dynamics, with their amino acid composition (e.g., G/Y-rich, Q-rich, S/R-rich, P-rich) dictating structural tendencies (e.g., β-sheet formation, phase separation ability). Functionally, LCDs mediate protein–protein interactions, drive liquid–liquid phase separation (LLPS) to form biomolecular condensates, and play roles in signal transduction, transcriptional regulation, cytoskeletal organization, and nuclear pore transportation. Pathologically, LCD dysfunction—such as aberrant phase separation or aggregation—is implicated in neurodegenerative diseases (e.g., ALS, AD), cancer (e.g., Ewing sarcoma), and prion diseases. We also summarize the methodological advances in LCD research, including biochemical (CD, NMR), structural (cryo-EM, HDX-MS), cellular (fluorescence microscopy), and computational (MD simulations, AI prediction) approaches. Finally, we highlight current challenges (e.g., structural heterogeneity, causal ambiguity of phase separation) and future directions (e.g., single-molecule techniques, AI-driven LCD design, targeted therapies). This review provides a comprehensive perspective on LCDs, illuminating their pivotal roles in cellular physiology and disease, and offering insights for future research and therapeutic development. Full article

Alzheimer’s disease (AD) is the most common cause of dementia, characterized by progressive cognitive decline and neuropathological hallmarks, including amyloid-β (Aβ) plaques, neurofibrillary tangles (NFTs), and neurodegeneration. Since the amyloid cascade hypothesis was proposed, Aβ has remained a central therapeutic target, with interventions aiming to reduce Aβ production, aggregation, or downstream toxicity. This review first outlines the historical development of the Aβ hypothesis and the two major APP processing pathways (α-cleavage and β-cleavage), highlighting the role of biomarkers in early diagnosis, patient stratification, and regulatory approval. We then summarize the development and clinical outcomes of anti-Aβ small-molecule drugs, including β-secretase inhibitors, γ-secretase modulators, Aβ aggregation inhibitors, receptor/synapse modulators, and metabolic or antioxidant modalities. We further review the progression of biologic therapies, with a particular focus on monoclonal antibodies, vaccines, and emerging gene-silencing strategies, such as small interfering RNA (siRNA) and antisense oligonucleotides. Finally, we discuss future perspectives, including next-generation biologics, multi-target approaches, optimized delivery platforms, and early-prevention strategies. Collectively, these efforts underscore both the challenges and opportunities in translating anti-Aβ therapies into meaningful clinical benefits for patients with AD. Full article

Hypochlorous acid (HClO) serves as a biological mediator and is widely utilized as a disinfectant in food processing and water treatment. However, excessive HClO residues in food and environmental water raise concerns due to the potential formation of carcinogenic chlorinated byproducts and disinfection byproducts (DBPs). Despite its importance, traditional methods for HClO detection often involve complex sample preparation, sophisticated instrumentation, and skilled operators. Herein, we report an aggregation-induced emission (AIE) small molecule fluorescent probe (NYV) that integrates colorimetric and ratiometric fluorescence responses for the detection of HClO. This probe exhibits high sensitivity, with a detection limit of 0.35 $\mathsf{\mu }$M, a rapid response time of 1 min, and a wide linear range (0–142.5 $\mathsf{\mu }$M), along with anti-interference capabilities, making it suitable for real-time monitoring. Furthermore, we have developed a portable solid-state sensor based on probe NYV for the rapid visual detection of HClO. The potential applications of this probe in real sample analysis and bioimaging experiments are demonstrated. Our findings contribute to the development of innovative fluorescent probes for HClO detection, with broad applications in food safety, environmental monitoring, and biomedical research on oxidative stress and ferroptosis. Full article