Search Results (167)

A convenient one-pot strategy was adopted to fabricate Cu-4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) nanosheets through the coordination of HEPES with copper ions under alkaline conditions, and the obtained nanosheets possessed dual laccase-mimetic and oxidase-mimetic activities for phenolic pollutant analysis and show potential for dye decolorization/removal. The Cu-HEPES nanosheets displayed significant dual enzyme-mimetic activities, effectively catalyzing the oxidation conversion for phenolic compounds, specifically 2,4-dichlorophenol (2,4-DCP), to yield quinone imine products characterized by a unique absorption signal at 500 nm. Meanwhile, Cu-HEPES nanosheets also facilitated the conversion of 3,3′,5,5′-tetramethylbenzidine to yield a yellow-green substance with a distinctive absorption signal at 458 nm. The Cu-HEPES nanosheets displayed a satisfactory affinity (K_m = 23.2 μM) for 2,4-DCP, facilitating its use in accurately detecting 2,4-DCP (linear range from 3.3 to 16.6 µM) with a detection limit of 0.3 µM. Subsequently, the devised colorimetric sensing platform was applied to measure 2,4-DCP levels in real tap water samples, yielding satisfactory spiked recoveries ranging from 92.7% to 106.9%. Finally, the synthesized Cu-HEPES nanosheets were preliminarily evaluated for the simultaneous decolorization/removal of malachite green and Congo red, suggesting their potential applicability in aqueous systems containing multiple organic dyes. Full article

Hierarchical functionalisation of the UiO-66(Zr)-NH₂ metal–organic framework with cysteine, poly(ethylene glycol) (PEG), and the SARS-CoV-2 spike receptor-binding domain (RBD) was developed to enable receptor-specific interaction with the angiotensin-converting enzyme 2 receptor (ACE2) in model cells. Post-synthetic modification using cysteine and heterobifunctional PEG linkers allowed controlled bioconjugation of SpyTag-labelled RBD via SpyTag/SpyCatcher chemistry, while preserving the crystallinity, microporosity, and intrinsic optical properties of the UiO-66(Zr)-NH₂ framework. Comprehensive physicochemical characterisation confirmed successful surface functionalisation, tunable aggregation behaviour, and retention of multimodal optical characteristics. Cellular studies in HEK293T and HeLa cells overexpressing EGFP-tagged ACE2 demonstrated enhanced and selective association and uptake of RBD-functionalised nanoparticles compared with non-targeted analogues. Multimodal fluorescence imaging, fluorescence lifetime imaging microscopy, flow-cytometry, and electron microscopy indicated ACE2-dependent endocytic internalisation, with predominant localisation in endosomal and autophagosomal compartments, while both amine- and cysteine-modified formulations exhibited good biocompatibility. Overall, this study establishes a virus-mimetic, ACE2-targeted UiO-66(Zr)-based nanosystem as a proof-of-concept biointerface platform for receptor-specific cellular delivery and imaging, providing a foundation for future MOF-based nanocarriers exploiting ligand–receptor interactions. Full article

Organoselenium chemistry has undergone remarkable development over the past five decades, evolving from its initial association with high toxicity into a field with pivotal contributions to materials science, organic synthesis, catalysis, and Medicinal Chemistry. Among the diverse biological activities displayed by organoselenium compounds, their redox behaviour is particularly compelling, as many of these molecules act as efficient mimetics of the antioxidant enzyme glutathione peroxidase (GPx). In this work, we investigated the GPx-like activity of a series of N,N′-diaryl selenoureas toward the depletion of H₂O₂ and cumene hydroperoxide (CumOOH) as model ROS. Their reactivity was correlated with the electronic nature of the aryl substituents using a Hammett-type analysis, revealing a strong dependence of the reaction rate on remote electronic perturbations within the aromatic ring. Combined UV and NMR studies provided mechanistic evidence supporting a catalytic cycle in which selenoureas, operating at sub-stoichiometric loadings (1 mol%) and using a thiol as a cofactor-like molecule, can be used to efficiently scavenge ROS with half-lives of only a few minutes (~10–60 min). Furthermore, these selenoureas exhibited potent antiproliferative activity across several human solid tumour cell lines. Overall, these results offer mechanistic insight into the ROS-eliminating pathways of selenoureas and highlight their potential as chemopreventive or anticancer agents. Full article

Metabolic dysfunction-associated steatotic liver disease (MASLD) is characterized by an exceptionally high global prevalence that is projected to continue rising in the near future. MASLD is strongly associated with a spectrum of cardiometabolic risk factors, and may itself, in turn, contribute to cardiovascular morbidity and mortality. This interconnection warrants the development of integrated treatment strategies targeting shared pathophysiological processes and addressing both hepatic, metabolic, and cardiovascular outcomes. In this work, we review the modern MASLD clinical development pipeline and highlight the most prominent drug candidates with known or purported cardiovascular benefits, discussing mechanistic links and supporting evidence ranging from preclinical experiments to real-world data. Although the drug development pipeline is extensive and diverse, evidence supporting cardiovascular benefits for most candidate molecules remains limited. Both of the FDA-approved therapies, resmetirom and semaglutide, have been found to significantly reduce the risk of major adverse cardiovascular events as well as cardiovascular and all-cause mortality in patients with MASH. In addition, significant improvements were observed in patients with heart failure with preserved ejection fraction treated with semaglutide, highlighting incretin mimetics as a promising class for managing cardiovascular disease concomitant with MASLD/MASH. Other investigational compounds, targeting the farnesoid X receptor, peroxisome proliferator-activated receptors, de novo lipogenesis enzymes, and fibroblast growth factors, have demonstrated improvements in blood lipid spectrum and glycemic control; however, their clinical effectiveness in patients at cardiovascular risk has yet to be established. Full article

Laccase plays an important role in the detection and degradation of phenolic compounds, but it is limited by its cost and stability. In this study, the laccase-like property of copper peptide (GHK-Cu) has been revealed. In terms of enzymatic reaction kinetics, GHK-Cu has a V_max of 1.735 × 10⁻⁴ mM·s⁻¹ and a K_m of 0.061 mM, demonstrating good substrate affinity and excellent catalytic efficiency. Then, a colorimetry was developed for rapid detection of epinephrine (EP) and 2-aminophenol (2-AP). The linear response range of EP is 20–240 μM, with a limit of detection (LOD) of 9.5 μM. The linear response ranges of 2-AP are 14–100 μM (in ultrapure water) and 2–120 μM (in seawater), with LODs of 2.56 μM and 1.65 μM. In addition, combined with a smartphone platform, a cotton-based sensor has been developed for the detection of 2-AP in seawater. The linear response ranges are 0–0.2 mM and 0.2–1 mM, with LOD of 0.033 mM. The structure of GHK-Cu provides a reference for the development of novel laccase mimetic enzymes. The constructed colorimetry offers an option for the rapid detection of phenolic compounds, and the developed cotton-based sensor enabled rapid and portable detection of 2-AP. Full article

Human induced pluripotent stem cell (iPSC)-derived brain organoids have emerged as powerful three-dimensional (3D) platforms for modeling human neurodevelopment and neurological disorders. However, the absence of a functional vascular network remains a critical limitation, restricting oxygen and nutrient delivery, impairing metabolic stability, and constraining long-term maturation. Conventional extracellular matrix (ECM) mimetics, such as Matrigel and other static synthetic hydrogels, provide biochemical support but fail to recapitulate the dynamic remodeling that characterizes the developing neurovascular niche. Recent advances in stimuli-responsive hydrogels offer spatiotemporal control over matrix stiffness, degradability, viscoelasticity, and biochemical cue presentation. In this review, we discuss dynamic hydrogel systems within a structure–property–function framework, highlighting how network chemistry and architecture may regulate endothelial sprouting, lumen formation, vascular stabilization, and neurovascular unit maturation in vascularized brain organoid models, based on evidence from both organoid studies and related biomaterial or vascular systems. Photoresponsive, enzyme-cleavable, thermo-responsive, supramolecular, bio-orthogonal click-based, and bioprinted platforms are discussed with emphasis on mechanotransduction, angiocrine signaling, and barrier specialization. Functional outcomes, including trans-endothelial electrical resistance, selective permeability, transporter expression, electrophysiological integration, and sustained perfusion, are discussed alongside translational challenges such as cytocompatibility, oxidative stress, scalability, and regulatory feasibility. Collectively, dynamic hydrogels provide a versatile biomaterial strategy for improving vascularization and aspects of functional maturation in brain organoid models with enhanced physiological relevance. Ultimately, stimuli-responsive hydrogel systems may serve as enabling platforms for engineering vascularized brain organoids and advancing human-relevant neurovascular disease modeling. Full article

The lung is highly susceptible to oxidative stress because of its exposure to high oxygen tension and environmental stressors, making tight regulation of the redox environment essential for homeostasis and disease pathogenesis. Extracellular superoxide dismutase (EC-SOD, sod3) is an important antioxidant enzyme in the lung that catalyzes the dismutation of superoxide into hydrogen peroxide and oxygen, thereby regulating the redox environment of the extracellular matrix, cell surfaces, and lining fluids of the lung. This review summarizes the structural features, post-translational regulation, genetic variations, and cellular sources of EC-SOD, with a particular focus on its role in acute respiratory distress syndrome (ARDS). We highlight evidence demonstrating that loss of EC-SOD exacerbates dysregulated immune responses, whereas enhanced EC-SOD activity confers protection in multiple experimental models of acute lung injury. We also discuss how inflammatory signaling, epigenetic regulation, aging, and genetic polymorphisms in the sod3 gene influence EC-SOD expression and function. Finally, we review emerging therapeutic strategies, including SOD mimetics and mRNA-based approaches, and address the challenges associated with non-specific antioxidant therapies in ARDS. Collectively, the data position EC-SOD as a central regulator of extracellular redox signaling and a promising, mechanism-driven therapeutic target in acute lung injury and ARDS. Full article

In this work, four different magnetic Fe₃O₄ nanoparticles are prepared via solvothermal method. According to the morphology, the products can be divided into flower-like Fe₃O₄ (F-Fe₃O₄), solid spherical Fe₃O₄ (S-Fe₃O₄), hollow spherical Fe₃O₄ (HO-Fe₃O₄), and hexahedral Fe₃O₄ (HE-Fe₃O₄). A set of measurements is performed to confirm the structure, composition, and pore properties of the obtained materials. The catalytic activities of the prepared materials are examined and compared. The results prove that the four materials have an intrinsic catalytic property. HO-Fe₃O₄ ranks first in the catalytic activity mainly due to its large surface area and reasonable element composition. The maximum specific saturation magnetization and specific surface area of HO-Fe₃O₄ are 72.94 emu/g and 42.60 m²/g. Fe²⁺/Fe³⁺ in HO-Fe₃O₄ is 51.5%. It is found that HO-Fe₃O₄ possesses fantastic stability and perfect reproducibility as it is used as a catalyst several times without significant loss in its activity. Full article

Caffeoyl hexapeptide-9 (CH-9) is a novel cosmetic peptide designed by conjugating hexapeptide-9 (H-9), a known collagen-mimetic peptide with established skin anti-aging activity, with caffeic acid (CA) via an amide bond, leveraging peptide-drug conjugate (PDC) design principles. In ultraviolet (UV)-irradiated cellular and skin models, CH-9 outperformed H-9 in preserving cell viability, restoring collagen types I, III, and IV, and suppressing interleukin-6 and -8 secretion. Additionally, its direct antioxidant activity, absent in H-9, was demonstrated in vitro by scavenging of hydroxyl and peroxyl radicals. Molecular docking indicated CH-9 interacted with the catalytic domain of matrix metalloproteinase 2 (MMP2), a key enzyme in collagen degradation during photoaging, suggesting a potential inhibition of its activity. Molecular dynamics (MD) simulations revealed an improved insertion of CH-9 into a stratum corneum (SC) lipid bilayer compared to H-9, consistent with enhanced skin permeation in vivo. Moreover, CH-9 exhibited improved aqueous and cosmetic serum stability over CA. In a 28-day clinical study, topical application of CH-9 significantly improved skin elasticity and firmness compared to H-9. This work demonstrates that the PDC-based conjugate CH-9 combines enhanced anti-photoaging efficacy with improved transdermal permeation and stability, highlighting a promising strategy for the development of advanced cosmetic ingredients. Full article

The ongoing COVID-19 pandemic, caused by SARS-CoV-2, continues to pose major global health challenges despite extensive vaccination efforts. Variant escape, waning immunity, and reduced vaccine efficacy in immunocompromised populations underscore the urgent need for complementary antiviral therapeutics. Here, we report the design, synthesis, and biological evaluation of precision-engineered dermatan sulfate (DS)-mimetic glycopolymers as multi-targeted inhibitors of SARS-CoV-2. Guided by molecular docking and virtual screening, sulfation at the C2 and C4 positions of iduronic acid was identified as critical for binding to the viral spike protein and inhibiting host and viral enzymes, including heparanase (HPSE) and main protease (M^pro). Chemically synthesized DS disaccharides were covalently grafted onto polymer scaffolds via a post-modification strategy, yielding glycopolymers with well-defined assembly that form uniform nanoparticles under physiological conditions. Surface plasmon resonance and pseudovirus assays revealed strong binding to the viral spike protein (K_D ≈ 177 nM), potent viral neutralization, and minimal cytotoxicity. Cellular uptake studies further demonstrated efficient internalization of nanoparticles and intracellular inhibition of HPSE and M^pro. These results establish a modular, non-anticoagulant, and glycosaminoglycan-mimetic platform for the development of broad-spectrum antiviral agents to complement vaccination and enhance preparedness against emerging coronavirus variants. Full article

Background: Diabetes mellitus is a multifactorial disease characterized by complex metabolic dysfunctions and chronic complications induced by hyperglycaemia. The design of multitarget ligands, capable of simultaneously controlling different pathogenic processes, was proposed as a promising approach to identify novel antidiabetic drugs endowed with improved efficacy. Methods: (5-Arylidene-4-oxothiazolidin-3-yl)alkanoic acid derivatives 1a–g and 2a–g were synthesized as potential multitarget antidiabetic agents. They were tested in vitro as inhibitors of both human recombinant AKR1B1 and PTP1B, and kinetic studies and molecular docking simulations for both enzymes were performed. Their effects on cellular glucose uptake, insulin signalling, and mitochondrial potential were assayed in cultures of murine C2C12 myocytes. A lipid accumulation assay was performed in HepG2 liver cells. The effects on high glucose-induced sorbitol accumulation were evaluated in lens HLE and retinal MIO-M1 cells. Results: All compounds displayed excellent AKR1B1 inhibitory activity (IC₅₀ 0.03–0.46 μM 1a–g; IC₅₀ 0.48–6.30 μM 2a–g); 1g and 2e–g also appreciably inhibited PTP1B at micromolar concentrations. Propanoic derivatives 2e–g significantly stimulated glucose uptake in C2C12 myocytes, in an insulin-independent way, reduced lipid accumulation in HepG2 liver cells, and caused hyperpolarization of C2C12 mitochondria at 10 μM concentration. Derivative 2e significantly reduced sorbitol accumulation in both HLE and MIO-M1 cells at a 5 μM concentration. Conclusions: The results reported here provided new insights into the mechanisms of action and structure/activity relationships of 4-thiazolidinone derivatives, underscoring the capability of compounds 2e–g of eliciting insulin-mimetic effects independent of hormone signalling. Among them, compound 2e also proved to inhibit AKR1B1-dependent sorbitol accumulation and, thus, emerged as a promising multitarget agent that can be considered for further investigations. Full article

Glycosaminoglycans (GAGs) are essential regulators of numerous biological processes through their interactions with growth factors, chemokines, cytokines, and enzymes. Their structural diversity and heterogeneity, however, limit reproducibility and translational use, as native GAGs are typically obtained from animal-derived sources with notable batch-to-batch variability. To overcome these challenges, a wide range of GAG mimetics has been developed with the aim of replicating or modulating the biological functions of native GAGs while offering improved structural definition, accessibility, and therapeutic potential. Polysaccharide-based GAG mimetics, including derivatives of heparan sulfate, hyaluronan, dextran, and other natural glycans, represent one major strategy, whereas non-saccharide-based mimetics provide alternative scaffolds with enhanced stability and selectivity. Both approaches have yielded compounds that serve as valuable tools for dissecting GAG/protein interactions and as candidates for therapeutic development. Biomedical applications of GAG mimetics span diverse areas such as cancer, cardiovascular and inflammatory diseases, bone and cartilage regeneration, wound healing, and infectious diseases. This mini-review summarizes key developments in the design and synthesis of GAG mimetics, highlights their potential biomedical applications, and discusses current challenges and future perspectives in advancing them toward clinical translation. Full article

Background/Objectives: Since its emergence, COVID-19—caused by the novel coronavirus SARS-CoV-2—has affected millions globally and led to over 1.2 million deaths in the United States alone. This global impact, coupled with the emergence of five new human coronaviruses over the past two decades, underscores the urgency of understanding its pathogenic mechanisms at the molecular level—not only for managing the current pandemic but also preparing for future outbreaks. Small non-coding RNAs (sncRNAs) critically regulate host and viral gene expression, including antiviral responses. Among the molecular regulators implicated in antiviral defense, the microRNA-processing enzyme Drosha has emerged as a particularly intriguing factor. In addition to its canonical role, Drosha also exerts a non-canonical, interferon-independent antiviral function against several RNA viruses. Methods: To investigate this, we employed q/RT-PCR, Western blot, and immunocytochemistry/immunofluorescence in an immortalized normal human lung/bronchial epithelial cell line (NuLi-1), as well as a human colorectal carcinoma Drosha CRISPR knockout cell line. Results: In this study, we observed a striking shift in Drosha isoform expression following infection with multiple SARS-CoV-2 variants. This shift was absent following treatment with the viral mimetic poly (I:C) or infection with other RNA viruses, including the non-severe coronaviruses HCoV-OC43 and HCoV-229E. We also identified a distinct alteration in Drosha’s cellular localization post SARS-CoV-2 infection. Moreover, Drosha ablation led to reduced expression of SARS-CoV-2 genomic and sub-genomic targets. Conclusions: Together, these observations not only elucidate a novel aspect of Drosha’s antiviral role but also advance our understanding of SARS-CoV-2 host–pathogen interactions, highlighting potential therapeutic avenues for future human coronavirus infections. Full article

Oxidative stress and inflammation are deeply interconnected processes implicated in the onset and progression of numerous chronic diseases. Despite promising mechanistic insights, conventional antioxidant and anti-inflammatory therapies such as NSAIDs, corticosteroids, and dietary antioxidants have shown limited and inconsistent success in long-term clinical applications due to challenges with efficacy, safety, and bioavailability. This review explores the molecular interplay between redox imbalance and inflammatory signaling and highlights why conventional therapeutic translation has often been inconsistent. It further examines emerging strategies that aim to overcome these limitations, including mitochondrial-targeted antioxidants, Nrf2 activators, immunometabolic modulators, redox enzyme mimetics, and advanced delivery platforms such as nanoparticle-enabled delivery. Natural polyphenols, nutraceuticals, and regenerative approaches, including stem cell-derived exosomes, are also considered for their dual anti-inflammatory and antioxidant potential. By integrating recent preclinical and clinical evidence, this review underscores the need for multimodal, personalized interventions that target the redox-inflammatory axis more precisely. These advances offer renewed promise for addressing complex diseases rooted in chronic inflammation and oxidative stress. Full article

In response to the ongoing challenges associated with natural enzymes, their high production costs, low stability and limited functionality; nanozymes have rapidly emerged as versatile alternative. Such nanocatalysts, based on nanomaterials and nanostructures, offer remarkable tunability of physicochemical properties and excellent durability, and adapt themselves effectively to the requirements of modern biotechnological applications. This review article aims to provide a comprehensive overview of recent advances in the use of naturally occurring iron oxide nanoparticles, produced by magnetotactic bacteria, and to highlight their emerging role as key elements in the development of the new generation of nano-guided biosensors. It provides a comprehensive and systematic analysis of publications in the Web of Science database between 2022 and August 2025, conducted in accordance with PRISMA guidelines. The aim was to assess the current state of the art and identify knowledge gaps in the exploration and application of magnetotactic bacteria as natural and sustainable sources in the design of next-generation biosensors. The natural nanoparticles, formed through biological processes, represent a unique and sustainable alternative to synthetic nanoparticles, offering naturally mimetic enzymatic activity, high biocompatibility, and exceptional stability. This approach opens up revolutionary perspectives in the field of biosensors, proposing a new class of functional materials, iron nanoparticles of biological origin, capable of fundamentally changing the performance, sustainability and reliability of future nanoenzymatic sensing platforms. Full article