Search Results (4,646)

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

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

Silver diamine fluoride (SDF) is widely used in pediatric dentistry for caries arrest; however, concerns exist regarding its cytotoxicity. Green-synthesized nano-silver fluoride (NSF) is a potential alternative to SDF, offering antimicrobial efficacy with improved biocompatibility. This study aimed to evaluate the in vitro safety profile of green-synthesized NSF with 5% (w/v) fluoride using Camellia sinensis extract and to compare it with 38% SDF + potassium iodide (KI) formulation in human gingival fibroblasts (HGFs). Eluates of NSF and SDF+KI were tested at serial concentrations of 5%, 1%, 0.1%, 0.01% and 0.005%. Cell viability was assessed after 24, 48, and 72 h using the MTT assay. Additionally, the formation of reactive oxygen species (ROS) in HGFs was detected through fluorescence microscopy. Exposure to 5% SDF+KI resulted in almost complete loss of cell viability at all time points, whereas NSF demonstrated significantly higher viability under the same conditions. Lower concentrations of both materials maintained acceptable biocompatibility. ROS analysis revealed increased oxidative stress in response to 5% SDF+KI, while NSF induced significantly lower ROS levels. NSF exhibited superior biocompatibility compared to SDF+KI, supporting its potential as a safer silver-based material for caries management. Further in vitro and in vivo studies are needed to confirm its clinical safety profile. 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

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

Silver nanoparticles (AgNPs) are widely recognized for their potent antibacterial properties and diverse biomedical applications. While conventional synthesis methods typically rely on chemical-reducing agents that may pose risks to human health and the environment, this study proposes an eco-friendly green synthesis approach utilizing porcine skin extracts. The extracts were prepared through thermal treatment and filtration to serve as a biological reducing agent. Successful synthesis was validated using dynamic light scattering, Fourier transform infrared (FTIR) spectroscopy, UV–Vis spectroscopy, and scanning electron microscopy (SEM). Furthermore, the antimicrobial efficacy of the synthesized AgNPs was evaluated against multidrug-resistant microorganisms, demonstrating significant growth inhibition across various antibiotic-resistant strains. These findings suggest that porcine skin—a readily available bioresource—is a promising precursor for the sustainable production of AgNPs with broad-spectrum antimicrobial potential. Full article

Green synthesis is an eco-friendly, simple, and cost-effective process for the synthesis of metal nanoparticles from plant extracts that are rich in bioactive compounds. In the current study, the antioxidant potential and total soluble polyphenol content (TPC) of different parts of Ligusticum mutellina (L.) Crantz were evaluated using DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing antioxidant power) assays, and the results indicated that the seed extract was the most active plant part. HPLC analysis indicated the presence of phenolic compounds such as gallic acid, protocatechuic acid, and catechin, which may contribute to the reduction and stabilization of AgNPs. Silver nanoparticles (AgNPs) were synthesized from the aqueous seed extract of L. mutellina. The formation of nanoparticles was confirmed by UV–Vis spectroscopy, FT-IR analysis, powder X-ray diffraction (PXRD), and transmission electron microscopy (TEM). The UV–Vis spectrum indicated a surface plasmon resonance peak at around 411 nm, and PXRD analysis indicated an average crystallite size of around 13 nm. TEM analysis revealed predominantly spherical nanoparticles with an average size of 25.36 ± 10.76 nm. The synthesized AgNPs exhibited strong antibacterial activity against Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. Overall, the results demonstrate that L. mutellina seed extract represents an effective natural source of reducing and stabilizing agents for green nanoparticle synthesis and highlight the potential of the obtained AgNPs as environmentally friendly antimicrobial materials. Full article

Radiation therapy is an essential mode of treatment for cancer, but it is limited by resistance, potential damage to healthy tissue, and inefficacy in later-stage cancers. To overcome these limitations, nanoparticles made from high atomic number (Z) atoms, such as silver (AgNPs), gold (AuNPs), and hafnium oxide (HfONPs), have been investigated for their ability to increase radiation dose deposition in cancer cells. Historically, it is believed that radiation dose enhancement primarily is achieved by physical mechanisms like photoelectric and Compton effects. Based upon these mechanisms, the usage of high Z nanoparticles would be expected to have relatively small dose enhancements and a lack of selectivity towards cancer cells under most clinical irradiation conditions. However, high Z nanoparticles exhibit very promising radiosensitizing effects that cannot fully be accounted for by physical effects, suggesting underlying biological interactions with relevant cellular processes caused by the nanoparticles themselves. Specifically, high Z nanoparticles can directly damage proteins and vesicles involved in degradation pathways (e.g., lysosomes and autophagosomes) and induce lipid peroxidation. The observed radiosensitizing effects of high Z nanoparticles may be caused by the sublethal cytotoxic responses of cancer cells to the nanomaterials themselves and are significantly greater than expected, based upon the macroscale physical dose increases in radiation deposition due to the presence of nanomaterials. This review critically analyzes the underlying biological mechanisms that could contribute to the enhancement of radiation effects by these nanomaterials. Full article

Diseases caused by pathogenic microorganisms in Bombyx mori have long been a major constraint on the sustainable development of sericulture. Current preventive strategies remain substantially constrained by issues of drug resistance and environmental compatibility. In recent years, the application of nanomaterials for pathogenic microorganism control has garnered escalating attention. Among these, chitosan–silver nanoparticles (CS-Ag NPs), as an emerging class of nanocomposites, integrate the biocompatibility and biodegradability of chitosan with the robust antimicrobial activity of silver nanoparticles, thereby exhibiting considerable potential for preventing pathogenic infections. Nevertheless, the efficacy of CS-Ag NPs against B. mori pathogens has not previously been documented. In this study, CS-Ag NPs were successfully synthesized via chemical reduction. Their antiviral activity was validated using quantitative PCR. The inhibitory efficacy of CS-Ag NPs against Bacillus bombysepticus and Serratia marcescens was evaluated through in vitro inhibition zone assays and bacterial growth curve analysis, with the minimum inhibitory (MIC) concentration for both pathogens determined. Notably, CS-Ag NPs exhibited no significant inhibitory effect on filamentous fungi, potentially due to the impaired ability of nanoparticles to penetrate fungal cell walls. Preliminary mechanistic investigations into the antimicrobial mechanism of CS-Ag NPs were conducted from the perspectives of oxidative stress. Our data showed that CS-Ag NPs could effectively alleviate ROS accumulation induced by the pathogen. In summary, our work systematically investigates the potential of CS-Ag NPs in controlling pathogens and enables the preliminary elucidation of their antibacterial mechanisms. These findings establish a theoretical foundation for the development of pharmaceuticals against pathogenic microorganisms and also offer novel insights into the ecofriendly management of diseases. Full article

The use of nanoparticles (NPs) synthesized from plant extracts is an alternative to conventional pesticides for the control of agricultural pests. This study aimed to optimize the conditions of synthesis of silver–zinc nanoparticles (Ag-ZnNPs) using extracts of Ocimum basilicum L. and Crotalaria longirostrata Hook. & Arn. and to evaluate their phytotoxic impact on maize seedlings. The Ag-ZnNPs (Ag-Zn nanoparticles) were synthesized by redox reaction between metal ions and reducing metabolites present in the extracts. A response surface methodology (RSM) with three factors (extract concentration, heating time and pressure) was applied to determine the optimal synthesis conditions. The phytotoxicity of nanoparticles (NPs) on maize seedlings was subsequently evaluated on root growth, oxidative stress enzymes (CAT, POD, and APX), and physiology of seedlings. Nanoparticles synthesized from C. longirostrata extract demonstrated superior properties, with an optimization of synthesis (R² = 95.3%) where the extract concentration (1:4 v/v; p < 0.01) was the critical factor influencing the reduction of metallic ions to nanoparticles. These NPs exhibited superior stability, smaller size (<100 nm), and zeta potential greater than 30 mV compared with O. basilicum extracts. Their NPs exhibited poorer optimization of synthesis (R² = 43.8%) without the effect of any of the variables evaluated. Essentially, C. longirostrata NPs showed no phytotoxic effects on maize seedlings’ physiological parameters and enhanced root growth (117.2 mm) without negatively affecting photosynthesis (PSII 70-81 FvFm). Ag-ZnNPs synthesized with C. longirostrata exhibited optimal stability and size, along with no observed possible phytotoxicity effects, unlike O. basilicum NPs, which cause stress on maize seedlings. Therefore, Crotalaria longirostrata NPs could represent a promising material for agricultural pest control, with no apparent adverse effect on maize crops. Full article

Inspired by their biocompatibility and thermoreversible gelation—transitioning from room temperature liquids to body temperature gels—Pluronic hydrogels were employed in this study to optimize intracanal penetration and ensure medicament stability. We developed a silver nanoparticle (AgNP)-loaded Pluronic gel (AgNPs-P-gel) as a biocompatible, easily removable intracanal medicament. Following PRILE 2021 guidelines, AgNPs-P-gels (F127/F68) were evaluated for gelation, AgNP release, and antibacterial activity against Enterococcus faecalis and Streptococcus mutans via minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and growth curves. Biofilms in bovine teeth were quantified using CFUs and scanning electron microscope (SEM) imaging. Biocompatibility was tested in L-929 fibroblasts using MTT assays and RT-qPCR for pro-inflammatory cytokines (IL-6, TNF-α, IL-1β). Removal efficacy from bovine canals was microscopically scored. The optimized formulation (20% F127, 7.5% F68) gelled at 34 °C with sustained release over 168 h. AgNPs-P-gel showed strong antibacterial activity (MIC: 25–50 µg/mL). In ex vivo models, 100 µg/mL AgNPs-P-gel (AgNPs-100-P-gel) reduced bacterial counts comparably to calcium hydroxide and chlorhexidine, but with lower cytotoxicity. Although inducing cytokine expression similar to conventional medicaments, AgNPs-P-gel demonstrated significantly superior removability. Thermoreversible AgNPs-P-gel offers sustained antimicrobial action, favorable biocompatibility, and superior removability, potentially improving endodontic disinfection predictability as a calcium hydroxide alternative. Full article

Objective: The objective of this study is to evaluate the ability of silver oxide nanoparticle (Ag₂ONP)-functionalized high-efficiency particulate air (HEPA) filters and colloidal Ag₂ONP suspensions to inhibit biofilm formation by major respiratory pathogens causing infections at operating rooms. Background: Respiratory infections caused by bacterial pathogens such as Streptococcus pneumoniae, Pseudomonas aeruginosa and Staphylococcus species are often associated with the formation of biofilms, which confer increased resistance to antibiotics and host immune responses. Effective strategies to prevent biofilm formation on biological surfaces and in air filtration systems are urgently needed in clinical settings. Methods: The biofilm-forming ability of each bacterial strain was assessed by crystal violet microplate assay, viable count or confocal microscopy after prior incubation of the culture medium with Ag₂ONP-coated HEPA filter material or colloidal Ag₂ONP suspension. Results: Both silver-functionalized filters and silver nanoparticle suspensions significantly inhibited biofilm formation by S. pneumoniae and P. aeruginosa, with near-complete suppression observed. In the case of S. aureus and S. epidermidis, the silver nanoparticle suspension showed partial inhibition of biofilm development. Conclusions: Ag₂ONP-functionalized HEPA filters and colloidal Ag₂ONP suspensions effectively prevent biofilm formation by major respiratory pathogens, for both Gram-negative and Gram-positive bacteria. These materials show promise for integration with air filtration and surface coating systems to reduce microbial load and transmission in healthcare environments such as operating room facilities. Full article

Green-synthesized silver nanoparticles (AgNPs) exhibit outstanding antibacterial and antioxidant potential for designing and developing nanomedicines and medical devices. Nephelium lappaceum or rambutan contains polyphenol-based phytochemicals, which suggests its suitability for the green synthesis of NPs. However, the lack of a systematic approach directly impacts the robustness and reproducibility of the process. Design of experiments can address these challenges in obtaining NPs with the desired quality profile. In this work, we demonstrated the advantages of a Plackett–Burman model in the semi-automated green synthesis of AgNPs using N. lappaceum peel extract. The extract concentration was the only significant factor affecting the particle size. The optimized NPs exhibited triangular and hexagonal morphologies and a hydrodynamic diameter of 80 nm after 24 h without a stabilizing agent, representing 1.2% prediction error according to the model’s equation. The in vitro antioxidant capacity was confirmed through the ABTS radical scavenging assay. The AgNPs displayed a minimum inhibitory concentration of 23.5 µg mL⁻¹ against Escherichia coli and Staphylococcus aureus. Overall, this work highlights the synergistic role between a DoE-assisted green synthesis, the phytochemicals from N. lappaceum peel extract, and the formed AgNPs, positioning this systematic approach as a sustainable and efficient process for novel antibacterial and antioxidant agents. Full article