Search Results (278)

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

Antimicrobial resistance is a major global health threat, creating an urgent need for effective non-antibiotic antimicrobial strategies. In this study, CS–AgNPs were synthesized by electron-beam radiolysis, providing a clean, dose-controllable route that avoids additional chemical reducing agents. The effects of irradiation dose and chitosan concentration on nanoparticle formation, physicochemical properties, and antibacterial activity were systematically evaluated. Spectroscopic and structural analyses confirmed the formation of highly crystalline, face-centered cubic silver nanoparticles uniformly dispersed within the chitosan matrix, with Ag–polymer coordination involving –NH₂ and –OH functional groups. Under the optimal conditions (8 kGy, 0.06 mmol AgNO₃, and 0.05% w/v chitosan), ultrasmall, well-dispersed CS–AgNPs were obtained, with an average size of 5.30 ± 2.01 nm and high phase purity. Antibacterial evaluation demonstrated potent, concentration-dependent activity against both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli, with low minimum inhibitory and minimum bactericidal concentrations (MIC/MBC = 1.96 µg/mL). These findings define a clear structure–property–activity relationship and support a synergistic antibacterial effect between nanosilver and chitosan, while maintaining favorable in vitro cytocompatibility and hemocompatibility within the effective concentration range. Overall, electron-beam radiolysis represents a promising scalable platform for producing broad-spectrum antimicrobial nanomaterials with potential utility in addressing antimicrobial resistance. Full article

Background: Nanomaterials have emerged as a transformative approach in modern pharmaceutical applications, offering advanced benefits compared to conventional therapies. Among available pharmaceutical nanomaterials, silver nanoparticles (AgNPs) have been reported with broad-spectrum antimicrobial potential and drug delivery potency. Nevertheless, some studies suggested that chemical synthesis of AgNPs might result in redundant chemicals, posing environmental and health risks. To minimize undesired products, a promising approach is to biologically synthesize this potent nanomaterial. Methods: This study ultilized an eco-friendly system for AgNPs synthesis using Aspergillus terreus isolated from the air. Physical properties of biosynthesized AgNPs were evaluated by UV–visible spectroscopy, dynamic light scattering, and scanning electron microscopy analysis. Antibacterial activity of biosynthesized AgNPs was examined by well diffusion and minimum inhibitory concentration, while in vitro cytotoxicity was used to determine the antitumor activity of AgNPs. Results: The biosynthesized AgNPs had a size of around 60 nm, a PDI inferior to 0.2, and a zeta potential of −30 mV. They exhibited potent antibacterial activity against both Gram-positive and Gram-negative pathogens. Additionally, these nanoparticles also exerted a selective antiproliferative effect on MCF-7, A549, and MDA-MB-231 cell lines. Conclusions: Our research presented the potential of biosynthesized AgNPs using Aspergillus terreus for antimicrobial and anticancer applications, offering an eco-friendly and sustainable alternative to traditional chemical methods. Full article

Background/Objectives: Wound infections caused by multidrug-resistant Gram-negative bacteria, such as Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii, pose a major clinical challenge. This study evaluated the interactions between gamma-polyglutamic acid (γ-PGA), cefiderocol, and silver nanoparticles (AgNPs) within multilayer wound dressing configurations. The primary goal was to clarify the dual role of γ-PGA as a healing promoter and a potential protector of bacterial cells against antimicrobial agents. Methods: Multilayer dressing models were assembled in 96-well plates to simulate vertical stratification of antimicrobial layers4. Bacterial viability was assessed through relative OD₆₀₀ measurements following incubation with varying concentrations and spatial arrangements of cefiderocol, AgNPs, and γ-PGA. Data were analyzed using generalized linear modeling (GLM) with a gamma distribution and random forest regression to determine the relative importance of each factor in modulating bacterial survival. Results: γ-PGA concentration emerged as the dominant factor influencing bacterial viability, accounting for nearly 100% of variable importance in random forest analysis. Despite high antimicrobial pressure from cefiderocol and AgNPs, bacterial viability stabilized at approximately 40% in the presence of γ-PGA. The vertical positioning of γ-PGA significantly impacted survival; direct physical contact between the polymer and bacteria, particularly at high concentrations, enhanced bacterial persistence in P. aeruginosa and E. coli. Cefiderocol showed strain-specific potency, while AgNPs provided consistent growth inhibition. Conclusions: γ-PGA plays a paradoxical role in wound care by providing moisture retention while simultaneously acting as a cytoprotective agent that reduces antimicrobial efficacy, likely by facilitating biofilm formation. These findings underscore the necessity of optimizing the spatial layering and concentration of biopolymers in advanced dressings. Strategic design is crucial to balance regenerative benefits with maximal antimicrobial control to improve clinical outcomes in chronic wound management. Full article

Due to the heightened flood risk resulting from climate change, innovative and advanced green building materials are required to enhance the durability and biological resistance of concrete structures exposed to persistent moisture. This study investigates the use of nanosilver-enriched plasticizers as a novel modification of concrete for applications in flood-prone environments. The findings demonstrate that the incorporation of nanosilver enhances the mechanical strength of concrete by reducing surface tension and porosity, thereby enhancing durability and extending service life. Moreover, nanosilver-modified concrete exhibits significant antimicrobial activity, effectively limiting microbial-induced corrosion. Preliminary microbiological analyses showed a reduction of sulfur-oxidizing bacteria (SOB) and sulfate-reducing bacteria (SRB) by 85–92%, as well as a decrease of over 80% in potentially pathogenic microbial genera. This study also highlights the importance of skilled labor and adequate training to ensure the responsible implementation of nanosilver-based technologies in sustainable construction. Overall, nanosilver-enriched plasticizers represent an innovative green building material that supports flood-resilient, durable, and sustainable concrete construction. Full article

Cut flowers of Matthiola incana ‘Mera’ are widely used in floristics but because of wilting, premature leaf yellowing, and flower/inflorescence drying their ornamental value quickly drops. The postharvest performance of this valuable cut flower in terms of symptoms of wilting, relative water content (RWC), carbohydrate content, enzyme activity, and free proline content was studied in relation to the different preservative added to the vases with flowers. The tested preservatives were based on two biocides: 200 mg/L 8-hydroxyquinoline citrate (8-HQC) and nanosilver (NS) in two concentrations, 1 and 5 mg/L, with the addition of 2% sucrose (S). Control inflorescences were kept in distilled water alone. The above preservatives did not prolong vase life, but, on the contrary, decreased it, so flowers placed in distilled water lasted the longest. The contents of both total soluble and reducing sugars increased during flower senescence, reaching the highest level in flowers held in the solution of 5 mg/L NS plus 2% S. Similarly, the content of free proline increased, especially in flowers held in the 8-HQC with 2% S (standard preservative). The contents of hydrogen peroxide (H₂O₂) varied in flowers from different solutions; however, they kept increasing during senescence in flowers from all the treatments. The highest activity of the antioxidative enzymes was found in flowers placed in water. Full article

Sintered nano-silver is widely investigated as a die-attach material for next-generation power electronic modules due to its high thermal conductivity, favorable electrical performance, and stability at elevated temperatures. However, how bonding pressure and joint thickness jointly affect densification, interfacial diffusion, and mechanical reliability has not been systematically clarified, especially under the low-pressure conditions required for large-area SiC and GaN devices. In this work, nano-silver lap-shear joints with three bond-line thicknesses (50, 70, and 100 μm) were fabricated under two applied pressures (1.0 and 1.5 MPa) using a controlled sintering fixture. Shear testing and cross-sectional SEM were employed to evaluate the relationships between microstructural evolution and joint integrity. When the bonding pressure was increased from 1.0 to 1.5 MPa, more effective particle rearrangement and reduced pore connectivity were observed, together with improved metallurgical bonding at the Ag–Au interface, leading to a strength increase from 15.3 to 28.2 MPa. Although thicker joints exhibited slightly higher bulk relative density due to greater heat retention and accelerated local sintering, this densification advantage did not lead to improved mechanical performance. Instead, the lower strength of thicker joints is attributed to a narrower Ag–Au interdiffusion region, which limited the formation of continuous load-bearing paths at the interface. Fractographic analyses confirmed that failure occurred predominantly by interfacial delamination rather than cohesive fracture, indicating that the reliability of the joints under low-pressure sintering is governed by the quality of interfacial bonding rather than by overall densification. The experimental results show that, under low-pressure sintering conditions (1.0–1.5 MPa), variations in bonding pressure and bond-line thickness lead to distinct effects on joint performance, with the extent of Ag–Au interfacial interaction playing a key role in determining the mechanical robustness of the joints. Full article

Background: Early childhood caries is defined as a carious disease affecting primary teeth in children under 6 years of age. It may lead to pain, infections, and difficulties with eating. Despite its burden, evidence on simple, non-invasive preventive approaches which can be implemented both in dental clinics and outreach services is fragmented. The aim of this review was to identify and map such methods for the secondary and tertiary prevention of ECC and to define priorities for future research. Material and Methods: The scoping review followed the PCC framework (Population–Concept–Context). Two databases were searched: PubMed and Scopus. A systematic search was conducted in PubMed and Scopus between 1 August and 30 September 2025. Eligible studies included children under 6 years of age with existing carious lesions, evaluated non-invasive methods for secondary and tertiary ECC prevention (such as sodium fluoride (NaF), silver diamine fluoride (SDF), nano-silver fluoride (NSF), and motivational techniques), requiring simple armamentarium, and reported data on the effectiveness in the context of ECC. Only publications from the past 5 years, available in English, and in open access, were considered. The results of the analysis were summarized narratively, outlining intervention types based on their characteristics, impact, and usage context. Results: Fifteen studies were included. Most were randomized controlled trials (eight studies), focusing primarily on silver diamine fluoride (SDF), often compared with other non-invasive methods, followed by systematic reviews (two studies), reviews (two studies), cross-sectional studies (two articles), and one qualitative study. Only one publication examined the use of motivational interviewing within the context of ECC. While the evidence on non-invasive approaches is growing, significant gaps remain. Small sample sizes, short follow-up periods, and heterogenous interventions and outcomes limit comparability. To strengthen the evidence base, future studies should recruit larger cohorts, adhere to standardized procedures, and use consistent reporting. Conclusions: The majority of studies focused on SDF, reflecting the increasing interest in its use. Research on motivational interviewing in ECC is particularly scarce. Further research under standardized conditions is needed to enable reliable comparisons across treatment protocols. Full article

There is limited understanding regarding the potential toxicity of nano-silver to crayfish. This study aims to evaluate the histopathological changes, oxidative stress, transcriptomics, and intestinal microbiota changes in different tissues of crayfish after exposure to nano-silver. The results showed that exposure to nano-silver caused pathological changes in the muscles, hepatopancreas, and gills of crayfish. Damage to muscular tissue progressively worsened with increasing concentrations of nano-silver, leading to a gradual widening of the gaps between muscle fibers. Nano-silver enlarged hepatopancreatic lumen and epithelial vacuolation, while the structure of the gills became disorganized, with severe damage to the gill membranes. The activities of peroxidase (CAT), superoxide dismutase (SOD), and glutathione reductase (GSH), as well as the content of malondialdehyde (MDA) in the muscles, hepatopancreas, and gills, were altered due to nano-silver exposure. Furthermore, along with the alteration of intestinal flora, there were alterations in the diversity of intestinal microbiota, an increase in the abundance of Bacteroides and Ca_Bacilloplasma, and a decrease in the abundance of Citrobacter. The abundance of harmful bacteria increased, causing intestinal inflammatory damage. Totals of 1549 and 1305 differently expressed genes (DEG) were found in the muscles and hepatopancreas, according to transcriptome analysis. Significantly affected pathways included the PPAR signaling pathway. These findings provide valuable insights into the use of nano-silver in the aquaculture of crayfish. Full article

The leaf nematode Aphelenchoides fragariae is one of the most serious pathogens of strawberries, causing significant yield losses. In search of environmentally friendly alternatives to chemical control, we evaluated the potential of vermicompost (Ve) and silver ions (Ag+) to suppress nematode populations. An experiment with four replicates was conducted to evaluate the effects of vermicompost and nanosilver on the leaf nematode A. fragariae and the yield of strawberry (Fragaria × ananassa). The study was conducted at The National Institute of Horticultural Research in Skierniewice in concrete rings (150 cm in diameter and 60 cm in depth) filled with medium sandy soil. Treatments included the application of vermicompost and Ag+, while untreated soil served as the control. Nematode population density, and total fruit yield were recorded in 2022 and 2023. The results demonstrated a significant decline in nematode populations compared with the control. Strawberry yields in 2022 and 2023 were 5.69 t/ha in the control, 6.61 t/ha with vermicompost (+0.92 t/ha), and 6.72 t/ha with silver nanoparticles (+1.03 t/ha). In the vermicompost treatment, the population of A. fragariae decreased by more than 51% in 2022 and by 79% in 2023. A similarly strong reduction was observed for nanosilver (Ag⁺), which lowered the nematode population by over 35% in 2022 and by 69% in 2023. Full article

This work concerns composite materials containing hydroxyapatite, fluorine, and nanosilver fillers. These composites are intended for the reconstruction of lost hard tooth tissues. The aim of the work was to evaluate the color stability of a flow composite containing hydroxyapatite, fluorine, and silver fillers after artificial thermal, chemical, and a combination of thermal and chemical aging processes. The samples were prepared from a commercial flow-type composite material (Arkona Flow Art, Niemcy, Poland) color A2 VITA (Vita Classical, Vita Zahnfabrick, Bad Sackingen, Germany) original and a modified composite material containing a filler additive of 2 wt.% hydroxyapatite powder containing fluorine (calcium fluoride) and nanosilver (n = 15). An Optishade (Style Italiano, Italy) colorimeter was used to measure color against a black background. Samples were submitted to thermal aging (T) using thermocycling equipment; to chemical aging (C) by immersion on artificial saliva at pH7, 37 °C; and to constant agitation or thermal–chemical aging using a combination of the previous two methods. The modified composite showed reduced color differences compared to the original composite. The results also show that thermal aging has a stronger influence on ΔE increase than chemical and combined aging, but only for the modified composite. Cumulative aging processes had an influence below the acceptability threshold for the modified composite. Full article

The aim of this research was to assess the sex-related responses to AgNPs stabilized with citrate (Cit) and glutathione (GSH), relative to silver ions supplied as AgNO₃ in black poplar (Populus nigra L.), a dioecious, woody model species. The impact of the AgNPs-cit-GSH on male and female clones was evaluated by measuring key parameters of oxidative stress. The results showed that exposure to nanosilver resulted in lower Ag accumulation and reduced MDA levels in both genders compared to AgNO₃. The female clone exhibited a dose-dependent response, characterized by an increase in dry weight (DW), along with a reduction in nutrient uptake, protein content, and ATPase activity, as well as an upregulation of glutathione-S-transferase (GST) activity compared to the control. The male clone displayed a specific treatment response. Exposure to AgNPs-cit-GSH caused a decrease in DW, water content, and nutrient uptake, accompanied by a rise in protein content as well as GST activity. In AgNO₃-treated male cells, the increase in Ag content and MDA levels corresponded to a decrease in DW and a rise in protein, Cu, and Ca content. These findings offer valuable insights into sexual dimorphism in dioecious woody plants, a topic that has been largely understudied yet is critical for sustainable resource management strategies. Full article

Implementation of novel antiviral coatings and textiles, which can be utilised in the production of personal protective equipment, has the potential to enhance public health security against future pandemic outbreaks. Respiratory viruses, particularly SARS-CoV-2, responsible for COVID-19, have emerged as a major global concern due to their rapid transmission and high mortality rates, leading to nearly seven million deaths worldwide between 2020 and 2025. This statistic underscores the necessity for the development and implementation of advanced antiviral materials to prevent viral infections. This research focused on the in vitro evaluation of the antiviral properties of three antibacterial compounds containing silver (Ag) that were functionalized with coatings. We assessed onsite synthesised Ag powder in comparison to commercially available antibacterial additives, which included nanosilver on colloidal silica (AgSiO₂) and silver sodium hydrogen zirconium phosphate (AgNaOPZr), as potential antiviral agents in coatings against human coronavirus (HCoV). Antiviral assessments revealed that coatings containing Ag at higher concentrations (2.5 and 5%) exhibited limited antiviral effectiveness, with a titer reduction in log < 2. In contrast, the functionalization of AgSiO₂ on coatings significantly suppressed viral replication resulting in a notable reduction in virus titer of log ≥ 2 for all tested concentrations. Full article

Sintered nano-silver paste is widely used in electronic packaging due to its excellent thermal and electrical conductivity. A phenomenological variable-order fractional constitutive model has been developed to characterize the evolution of its mechanical properties, incorporating dependencies on both temperature and strain rate. Based on the Weissenberg number and classical Arrhenius equation, a formulation for relaxation time with temperature and strain rate dependence has been proposed. A temperature- and rate-sensitive fractional order is introduced to capture the coupled influences of thermal and strain rate effects. Furthermore, the effects of temperature and the strain rate on the elastic modulus and relaxation time are quantitatively described through established coupling criteria. Simulation results demonstrate that the proposed model offers high accuracy and strong predictive capability. Comparisons with the classical Anand model highlight the effectiveness of the variable-order fractional model, particularly at lower temperatures. Full article

Objective: To investigate the influence of chitosan-based nano-silver fluoride (CNSF) treatment of tooth tissues on shear bond strength (SBS) of resin composite (RC) and resin-modified glass ionomer (RMGI) restorations. Methods: 90 extracted human molars were collected. Specimens were randomly assigned to three groups (n = 30): non-pretreated (NPT) pretreated with either CNSF or silver diamine fluoride (SDF). Each group was subdivided into two restorative subgroups (n = 15): RC and RMGI. Specimens in CNSF and SDF groups were pretreated with CNSF or SDF per their manufacturer’s instructions. Then specimens in RC subgroups were etched, treated with chlorhexidine cleanser, followed by adhesive application. Specimens in RMGI subgroups were treated with cavity conditioner only. A cylindrical restoration (2.38 mm θ × 2 mm height) of RC or RMGI restoration was fabricated with a standardized mold and light-cured on all specimens. After 5000 times of thermocycling between 5 °C and 55 °C with dwell times of 30 s intervals, SBS was measured using the Ultradent UltraTester. Data was analyzed statistically (α = 0.05) using ANOVA/Tukey’s comparisons. Results: No statistically significant difference in SBS among RC restorations in the three treatment groups: NPT (17.48 ± 3.96), CNSF (18.38 ± 5.59), and SDF (14.03 ± 6.56). For RMGI restorations, SBS was significantly (p < 0.05) higher in NPT (15.99 ± 3.59) compared to CNSF-treated (11.45 ± 5.48), but there was no significant difference between NPT and SDF-treated (14.27 ± 2.17) or between SDF- and CNSF-treated groups. Conclusions: No difference in SBS of resin composite restorations when the dentin tissue is pretreated with either chitosan-based nano-silver fluoride or silver diamine fluoride. However, SBS of RMGI was lowered when the dentin tissue was pretreated with CNSF. Full article