Search Results (5,017)

This study focuses on the development and characterization of advanced composite materials based on poly(ε-caprolactone) (PCL) and poly(vinylidene fluoride) (PVDF), with or without silver nanoparticles (AgNPs), planned for peripheral nerve or bone regeneration. The complementary properties of PCL (biocompatibility and biodegradability) and PVDF (mechanical stability and piezoelectric functionality) were exploited by blending the polymers in different ratios, resulting in binary (PCL/PVDF) and ternary (PCL/PVDF/AgNPs) composites. Green-synthesized AgNPs were integrated to enhance antimicrobial activity and to support tissue repair through improved signal transmission. Functional thin films and electrospun fibres were obtained and subjected to advanced characterization techniques, including scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermal analysis. The results demonstrated appropriate morphology, chemical composition, structural stability, and favourable interactions with simulated physiological media. Preliminary biocompatibility assays confirmed good cell viability, supporting the biomedical applicability of the designed scaffolds. Overall, the obtained results highlight the potential of AgNPs-functionalized PCL/PVDF binary and ternary composites as promising candidates for flexible, durable, and bioactive implants in peripheral nerve or bone regeneration. Full article

In this study, a cellulose nanocrystal (CNC)-supported Ag–ZnO nanocomposite was synthesized via a hydrothermal route as a polymeric photocatalyst for efficient UV-A light-driven dye degradation. The renewable CNC framework provides abundant hydroxyl functional groups for nanoparticle anchoring, enhancing dispersion and interfacial charge transfer. Structural (XRD, FTIR, TEM, PL, and XPS) and thermal (TGA and DTG) analyses confirm successful incorporation of Ag nanoparticles and retention of CNC crystallinity. The composite exhibits a reduced optical bandgap (3.02 eV) and demonstrates superior photocatalytic activity, achieving 96% methylene blue (MB) degradation within 120 min. Enhanced performance is attributed to the synergistic effect of Ag-induced plasmonic excitation and CNC-facilitated charge migration, effectively suppressing ZnO photocorrosion. Moreover, the optimization of the parameters was conducted and found to be pH 7, a catalyst dose of 0.3 g L⁻¹, and an initial MB concentration of 10 ppm, which shows the best photocatalytic degradation reaction. The CNC/Ag–ZnO catalyst maintains 87% activity after five reuse cycles, showing good stability and reusability. The photostability of the CNC/Ag–ZnO catalyst was evaluated by ICP-MS, which measured Zn²⁺ concentration in the aqueous solution. Additionally, the degraded MB compounds were identified using GC-MS/MS analysis. This work highlights the potential of polymer-based biogenic supports for sustainable photocatalyst design and bridges polymer science with environmental remediation technology. Full article

The peripheries of rare-metal metallogenic systems frequently host skarn-type or hydrothermal vein-type Pb-Zn deposits, though their genetic connections with parental systems remain debated. The newly identified Gariatong W-Mo polymetallic metallogenic system in the Lhasa Terrane displays well-defined Nb-Ta-Rb, Mo-W, W-Mo, W-Bi, and Pb-Zn-Ag metallogenic zoning, establishing it as an exemplary site for investigating genetic relationships between Pb-Zn and rare-metal mineralization. This investigation targets skarn-type Pb-Zn deposits spatially associated with rare-metal orebodies at Gariatong, utilizing integrated analytical approaches, including in situ LA-ICP-MS trace-element analysis of sulfides, sulfur isotope geochemistry, and LA-ICP-MS elemental mapping of sphalerite, to constrain metal sources, characterize fluid evolution, and establish genetic correlations with the rare-metal system. Key findings include the following: (1) sphalerite shows enrichment in Fe, Mn, Co, and Cd, while pyrite contains elevated As, Pb, Co, Cu, and Mn. Fe, Cd, and Mn primarily occur as solid solutions or nanoparticles, whereas As and Pb exist as micro-inclusions. (2) Sphalerite Zn/Cd ratios (73.6–184) and Co-Ni-As ternary diagrams confirm a magmatic–hydrothermal skarn origin. (3) Mineralization occurred under moderate-temperature, mildly oxidized conditions, as constrained by sphalerite Fe contents and mineral assemblages. Sulfur isotope compositions (δ³⁴S = −1.0‰ to 3.2‰; mean: 1.9‰) indicate a magmatic sulfur source. This study reveals that the Nb-Ta-Rb mineralization, quartz-vein- and greisen-type W-Mo deposits, and skarn-type Pb-Zn orebodies—all genetically associated with highly fractionated granites—constitute an integrated magmatic–hydrothermal system with vertical (depth-related) zoning relative to the granitic intrusion. These results provide critical constraints for understanding rare-metal–Pb-Zn genetic associations and suggest that Pb-Zn mineralization may serve as a key exploration indicator for rare metals in the Lhasa Terrane. Full article

Chronic wounds resulting from bacterial infection remain one of the main challenges in clinical practice. There is a pressing need to develop an injectable hydrogel sealant with multifunctional properties, including remodeling capabilities, self-healing, painless removal, and antibacterial activity, to promote tissue remodeling. In this work, aldehyde carboxymethylated agarose (ACMA) is employed for the first time as a bio-template. Dopamine (DA) is introduced onto the ACMA template via a reversible Schiff-base reaction, endowing it with biomineralization properties to synthesize DA-modified ACMA-Ag nanoparticles (ACMA-DA-Ag). Further, the prepared ACMA-DA-Ag, which possesses both antibacterial activity and injectable behavior, is incorporated into a guar gum hydrogel through the formation of borate/diol bonds, thereby forming a multiple-dynamic-bond crosslinked network. This hydrogel demonstrates adequate mechanical strength, injectability, remodeling capabilities, and self-healing performance. It can reassemble into a new hydrogel within 4 ± 0.6 min upon simple physical contact, and supports tissue adhesion. Furthermore, the hydrogel effectively covers irregular-shaped wound and can be removed without causing secondary injury. More importantly, this multifunctional hydrogel is cost-effective, easy to synthesize, and simple to use, significantly accelerating skin regeneration and promoting the formation of skin appendages, such as hair follicles. The outcome of this research not only serves a tissue sealant for wound healing, but also presents a new strategy for creating novel polysaccharide-based biomaterials. Full article

Surface discharge-induced degradation poses a significant threat to the operational reliability of high-voltage insulation systems. This research investigates the dielectric endurance of polyester-based nanocomposites reinforced with seven distinct nano-additives: iron oxide (Fe₃O₄), copper oxide (CuO), titanium oxide (TiO₂), aluminum oxide (Al₂O₃), silicon dioxide (SiO₂), zinc borate (ZnB) and graphene oxide (GO). Specimens were fabricated at 0.5% and 0.75% weight concentrations and subjected to constant AC electrical stress of 4.5 kV at 50 Hz until failure using the first-plane tracking method. To accurately monitor the aging process, a sophisticated signal processing framework involving Hankel-matrix-enhanced Robust Principal Component Analysis (RPCA) was developed to extract high-frequency discharge features from captured leakage current signals. The degradation characteristics were quantified using various statistical metrics, including Kurtosis, RMS and Burst Discharge Index (BDI). Experimental findings demonstrate that the incorporation of nanoparticles significantly extends the time-to-failure compared to neat polyester, although the effectiveness is highly dependent on both additive type and concentration. At 0.5 wt.%, ZnB exhibited the superior performance in delaying carbonized track formation. However, at 0.75 wt.%, Al₂O₃ emerged as the most effective additive, achieving a maximum endurance time of 31.61 min. In contrast, certain additives like TiO₂ showed a performance decline at higher loadings, likely due to nanoparticle agglomeration. The Hankel-RPCA methodology successfully isolated discharge-specific signatures from background noise, establishing a strong correlation between signal features and material failure stages. This study confirms that the synergy between advanced nanomaterial modification and robust signal processing provides an effective diagnostic tool for monitoring insulation health, offering a vital pathway for the designing of high-performance dielectrics for real-world power system applications. Full article

Despite the growing adoption of Ti6Al4V-ELI made by Laser Powder Bed Fusion (LPBF) in tribologically demanding applications, the influence of hybrid nanoparticle additives on its lubrication behavior under starved contact conditions remains insufficiently explored. The tribological performance of Ti6Al4V was investigated under starved boundary-to-mixed lubrication conditions using engine oil modified with Ag-doped TiO₂ nanoparticles. Double-scan LPBF-fabricated discs were tested in a ball-on-disc configuration against AISI 52100 bearing steel using a TRB³ tribometer. Nanolubricants were prepared by dispersing TiO₂ and Ag–TiO₂ nanopowders with different Ag⁺/Ti⁴⁺ ratios (0.5%, 1.5%, and 2.5%) in SAE 10W-40 engine oil at a constant nanoparticle concentration of 0.05 wt%. Comprehensive physicochemical characterization of the nanopowders and nanolubricants was performed through structural, chemical, optical, morphological, rheological, and stability analyses. Tribological experiments were conducted following a full-factorial design combining three normal loads (5–15 N), three sliding speeds (0.10–0.20 m·s⁻¹), and four lubricant formulations. The steady-state coefficient of friction ranged between 0.281 and 0.359, while the specific wear rate varied from 2.81 × 10⁻⁴ to 4.83 × 10⁻⁴ mm³·N⁻¹·m⁻¹. The contact temperature rise remained relatively moderate, within the interval of 1.9–9.4 °C. Among the investigated formulations, the lubricant containing 1.5% Ag–TiO₂ exhibited the lowest friction coefficient, whereas the formulation with the highest Ag content showed improved stability of tribological performance across the investigated operating domain. These results indicate that Ag-modified TiO₂ nanoparticles are consistent with the formation of protective tribofilms and contribute to the stabilization of friction, wear, and thermal behavior under starved lubrication conditions. ANOVA confirmed that sliding speed and the load–lubricant interaction are the dominant factors governing friction and wear, while normal load controls the thermal response. These findings support the use of Ag–TiO₂ nanolubricants as a viable strategy for stabilizing interfacial behavior in LPBF-fabricated titanium components operating under starved lubrication conditions. Full article

Zinc oxide (ZnO) is a semiconductor with photocatalytic activity, although it presents limitations due to its band gap and the rapid recombination of the electron–hole pair; therefore, strategies such as doping have been explored. In this work, ZnO nanoparticles doped with 3% and 5% silver (Ag) were synthesized using a Cylindropuntia cholla root extract as a reducing and stabilizing agent. The structural, chemical, and optical properties of the synthesized nanoparticles were investigated using Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Cathodoluminescence (CL), X-ray Photoelectron Spectroscopy (XPS), and Energy-Dispersive X-ray Spectroscopy (EDS). FT-IR shows that the nanoparticles have peaks between 400 cm⁻¹ and 406 cm⁻¹, attributed to the Zn–O bond. XRD characterization confirmed the formation of the wurtzite crystalline phase of ZnO, as well as the cubic phase of Ag. CL reveals two peaks: one attributed to the ultraviolet (UV) region and another in the visible region, which is associated with defects in the lattice. XPS and EDS confirm the presence of Zn, O, and Ag in the samples. The degradation of methylene blue was 90.9%, 96.4%, and 97.0% for ZnO, 3AgZnO, and 5AgZnO, respectively, demonstrating an improvement in dye degradation efficiency when doping ZnO nanoparticles with Ag. Full article

This study explored the eco-friendly synthesis of AgNPs using Prosopis laevigata seed mucilage and assessed their antimicrobial, antibiofilm, and biocompatibility effects against foodborne pathogens. The AgNPs were mostly spherical, with sizes ranging from 2.5 to 56 nm (average: 14.69 nm), as confirmed by XRD and DLS analysis. They showed consistent antimicrobial activity, with MICs at 0.5 mg/mL and MBCs at 1.0 mg/mL across all tested strains, and inhibited bacterial growth by over 75% at 0.5–5 mg/mL, similar to or better than gentamicin. The antibiofilm performance was notable, with inhibitions of 76–84% against E. coli (1–10 mg/mL), 96–98% against S. aureus (0.5–10 mg/mL), 76–82% against Salmonella Typhimurium (0.5–10 mg/mL), and 70–84% against P. aeruginosa (1–10 mg/mL), surpassing gentamicin against E. coli and P. aeruginosa. Cell viability remained 100% at 0.25 mg/mL, and no significant changes in immunological parameters were observed, suggesting good biocompatibility at therapeutic doses. This research shows, for the first time, that P. laevigata mucilage is an effective bioreducing agent for green synthesis of AgNPs with antimicrobial and antibiofilm activity against both Gram-negative and Gram-positive foodborne pathogens. Its superior ability to inhibit biofilms compared to traditional antibiotics, along with its safety profile at therapeutic levels, makes these nanoparticles promising for food safety applications, antimicrobial coatings, and topical treatments. Overall, the findings support the use of native plant resources in green nanotechnology to address global challenges of antimicrobial resistance. Full article

Nanosomes—lipid vesicles at the nanoscale—enable the encapsulation of both hydrophilic and lipophilic actives and are increasingly used as skin delivery systems in cosmetic products. Alongside nanoemulsions, polymer nanocapsules, and inorganic nanoparticles (e.g., TiO₂, ZnO, Ag), they can enhance solubility, stability, residence time, and local bioavailability while enabling controlled release. This review summarizes nanocarrier structures, preparation concepts, and skin penetration pathways (transepidermal intercellular/transcellular and transappendageal), and discusses formulation factors that modulate delivery. We highlight applications in UV protection, anti-aging, and fragrance retention, focusing on lipid-based systems (liposomes/nanosomes, ethosomes, niosomes). Safety considerations are critically appraised with reference to EU and FDA frameworks, including physicochemical characterization, dermal penetration, irritation/sensitization, and genotoxicity testing. While most data indicate limited penetration through intact skin for particles ≥20 nm, enhanced uptake may occur under specific conditions (very small size, barrier impairment, mechanical stress), warranting careful risk assessment. We conclude with regulatory and sustainability perspectives and outline research priorities for long-term toxicology, in-use exposure, and standardization of methods. Full article

The green synthesis of nanoparticles offers a solution to control pesticide-resistant pests while minimizing environmental and health risks. Thrips tabaci is an injurious pest that attacks garlic crops and spreads the Iris yellow spot virus. The present research was performed to evaluate the synergistic effects of silver nanoparticles (AgNPs) synthesized by Teucrium polium with Spinosad against T. tabaci and assess their impact on garlic photosynthetic pigments. The characterization of the prepared nanoparticles was carried out by SEM, XRD, and Malvern zeta sizer. Antimicrobial activity was assessed using microdilution. Photosynthetic pigments were measured with a spectrophotometer after treating garlic cloves with four different concentrations of AgNPs and Spinosad mixture along with positive control (Spinosad) and negative control (tap water). Toxic bioassays were conducted under laboratory, greenhouse, and open field conditions. The results indicate all treatments, except for the 100% AgNPs, resulted in 100% second instar larvae and adult mortality after 72 h in the laboratory. In greenhouse conditions, the 50% Spinosad–50% AgNPs achieved 93.85% larvae mortality, and the 75% Spinosad–25% AgNPs achieved 100% adult mortality after a week. In open field conditions, the combination 50% Spinosad–50% AgNPs showed high efficacy, resulting in 65.97% mortality of larvae and 73.06% mortality of adults after 72 h. This study reveals that AgNPs have active pesticide properties against T. tabaci with minimal environmental and health risks. Full article

Silver-coated copper (Cu@Ag) core–shell nanoparticles are promising interconnect materials for electronic packaging due to their high conductivity, oxidation resistance, and reduced use of precious metals. However, the key factors governing their sintering behavior and mechanical performance are not fully understood. In this study, molecular dynamics simulations were performed to examine the effects of sintering pressure (300–700 MPa), temperature (500–700 K), particle size, and silver shell thickness on atomic diffusion, microstructural evolution, and mechanical properties. Results show that higher pressure improves particle contact, accelerates densification, and strengthens interfacial bonding, with optimal performance achieved at 600–700 MPa. Elevated temperatures enhance atomic mobility, promoting neck growth and pore elimination, with the most active diffusion observed between 650 K and 700 K. Particle size and shell thickness also affect sintering: the Ag6Cu3 configuration exhibits the highest atomic mobility and a balanced combination of strength and ductility. Moderately thick silver shells facilitate surface diffusion and interfacial interdiffusion, while mechanisms such as the Kirkendall effect and local plastic relaxation reduce defect density, yielding stable sintered structures. These findings provide atomic-scale insights into the sintering mechanisms of Cu@Ag nanoparticle solder pastes and offer guidance for optimizing processing parameters in high-performance electronic packaging applications. Full article

Modified chitosan (Cs) derivatives were synthesized and evaluated as potential antibacterial and antiviral coatings of medical protective equipment (facial masks, gloves, …). Quaternized chitosan (HTCC) and chitosan–silver nanocomposites (Ag/Cs) were successfully prepared, with structural characterization confirming efficient quaternization and uniform incorporation of silver nanoparticles. Antibacterial testing revealed that HTCC exhibited concentration-dependent activity, while Ag/Cs showed strong broad-spectrum antibacterial effects and enhanced thermal stability. Antiviral assays against SARS-CoV-2 demonstrated significant viral inhibition for HTCC6 and Ag/Cs at non-cytotoxic concentrations (6 mg/mL), highlighting the role of cationic charge and nanoparticle inclusion in antiviral efficacy. These findings indicate that the developed chitosan derivatives are promising candidates for sustainable functional coatings on medical devices, offering potential applications in infection prevention. Full article

Environmental pollutants, lifestyle factors, and intrinsic metabolism can amplify reactive oxygen and nitrogen species (ROS/RNS) generation beyond antioxidant capacity. The resulting oxidative stress damages macromolecules, perturbs redox signaling, and may accelerate biological aging. This review synthesizes evidence published mainly in 2020–2025 on how major pollutant classes (air pollutants, metals, pesticides, nanoparticles, and micro-/nanoplastics) induce ROS through shared nodes mitochondrial electron transport disruption, NADPH oxidase activation, and redox cycling/Fenton chemistry and how these signals propagate to epigenetic remodeling (DNA methylation, histone modifications, and non-coding RNAs). To move beyond descriptive cataloging, we grade the strength of evidence by study context (cell culture, animal models, human observational studies, and clinically oriented biomarker research), highlight convergent findings and unresolved controversies, and specify key methodological limits. We then compare oxidative-stress biomarker platforms by analytical specificity, pre-analytical susceptibility, and translational readiness, distinguishing validated markers from exploratory redox-epigenetic and multi-omics signatures. Finally, we discuss how exposomics and AI-assisted multi-omics integration may support biomarker discovery while emphasizing current constraints (confounding, batch effects, and limited prospective validation) that must be addressed for clinical translation. Full article

Contamination of water resources by organic pollutants is a major environmental issue. Utilizing photocatalytic materials for the degradation of these pollutants presents a viable strategy for environmental clean-up. This study introduces the synthesis of an organic/inorganic hybrid photocatalyst of β-cyclodextrin (β-CD)/reduced graphene oxide (rGO) and titanium oxide (TiO₂) nanoparticles. The nanocomposite was characterized by using FT-IR, XRD, SEM, and EDAX, and the photocatalytic activity was studied by measuring the photodegradation of methylene blue (MB) under simulated solar radiation. The synthesized nanocomposite showed excellent stability and performance, with up to 92% photodegradation of MB. To further enhance the photocatalytic activity, the synthesized nanocomposite underwent modification with Ag and Pt nanoparticles. Within 90 min, photodegradation rates of 100% and 97% for MB were attained with Pt and Ag nanoparticles that were loaded at 5 wt.%, respectively. The photocatalyst’s reusability was evaluated through multiple usage cycles. Additionally, the impact of functionalization on the band gap alteration of TiO₂ is reported. Full article

Zinc oxide (ZnO), silver (Ag) and titanium dioxide (TiO₂) nanoparticles (NPs), are three of the most widely manufactured NPs, while composite NPs have gained popularity due to their enhanced properties. NP release in environmental matrices increases chances of bioavailability and subsequent impact on human health. The current study focuses on manufacturing, characterization and cyto-genotoxic assessment of Ag, ZnO/Ag, TiO₂ and TiO₂/Ag NPs with and without humic acids (HAs), aiming for a holistic approach that leads to a comprehensive profile of said NPs. It entails (a) the synthesis of the aforementioned NPs via single-nozzle Flame Spray Pyrolysis (SN-FSP); (b) the characterization of NPs (in powder form and in dispersion media) using Powder X-ray Diffraction (PXRD), Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS); and (c) the assessment of their genotoxicity and cytotoxicity against human lymphocytes in presence of two HAs, thus simulating actual environmental conditions, and without HAs, through the cytokinesis block micronucleus assay (CBMN) with cytochalasin-B. No genotoxicity was observed in any case, whereas cytotoxicity induction varied depending on the NP and the presence or absence of the two HAs. Therefore, it is indispensable to evaluate the toxic profile of NPs considering different environmental scenarios, while conducting an integrated characterization of NPs. Full article