Search Results (3,813)

Photocatalytic degradation technology has been widely acknowledged for its low cost and high degradation efficiency. However, the loss, migration and difficult recovery of powdered catalysts are still critical bottlenecks for practical applications. In this study, silver nanoparticles (Ag NPs)/polyvinylidene fluoride (PVDF) photocatalytic composite membranes were in situ fabricated by incorporating AgNO₃ into a PVDF casting solution, followed by electrospinning and UV post-treatment. The resulting membranes exhibited sustained photocatalytic capability towards dyes and antibiotics. The optimal membrane achieved 89.6% and 83.0% degradation efficiency for chloramphenicol (CAP) and rhodamine B within 16 h under UV irradiation, respectively. Free radical trapping experiments revealed that the superoxide radical (·O₂⁻) dominated the photocatalytic degradation of CAP, and the mechanism of photocatalytic degradation was explored. Additionally, the Ag NPs/PVDF photocatalytic membrane demonstrated a distinct antibacterial efficacy against Staphylococcus aureus (S. aureus) with a distinct inhibition zone of 20 mm, effectively inhibiting bacterial proliferation. Full article

Strawberry is a nutritive fruit with a short life and postharvest losses. In this study, the quality and shelf life of strawberries during storage at 4 °C were evaluated after applying hurdle treatment of packaging with active polylactic acid (PLA)/Gelatine (G)-based films loaded with essential oils (EOs) and/or AgNPs and combined with low-energy (L-E) X-ray at a dose of 0.5 kGy. The results showed that the addition of EOs, AgNPs, or their combination decreased the tensile strength (TS) of films from 16.70 to 6.65–10.01 MPa and increased elongation at break (Eb) from 215.4 to 218.2–398.2%. The oxygen transmission rate (OTR) of films increased from 219.7 to 274.8–298.6 cm³/m²·day, which promoted the development of gas selective films for equilibrium-modified atmosphere packaging (EMAP). A level of 20% decay (primary shelf life criterion) of strawberries was observed on day 8 for the commercial control (polyethylene terephtalate clamshell), on day 9 for the PLA/G-AgNPs films, and on day 10 for the PLA/G-EOs films and PLA/G-EOs + AgNPs films. The combined application of the active films with L-E X-ray irradiation (PLA/G/EOs + AgNPs + I) extended the time to reach 20% decay to day 13 compared to day 9 for irradiated commercial control. An EMAP was achieved after 6–9 days of storage, with a gas composition around 13–14% O₂ and 8–9% CO₂. The combined treatment of EOs, AgNPs containing films, and L-E X-ray irradiation prevented firmness and total soluble solid loss of strawberries. The redness of strawberries and their total phenolic/anthocyanin content increased after irradiation treatment and maintained significantly higher levels (p ≤ 0.05) than those of non-irradiated samples during storage. This study demonstrates the effectiveness of combining active PLA/G films and L-E X-ray irradiation in extending the shelf life and preserving the quality of fresh strawberries. Full article

Background/objectives: Delayed wound healing, along with excessive scar formation, is the major clinical drawback due to the presence of stubborn bacteria, oxidative stress, prolonged inflammation, and irregular tissue regeneration. Utilizing nanomaterial-based wound dressings offers significant advancements and minimal cytotoxicity, but also presents issues such as poor biocompatibility, low solubility, and reduced permeability. These factors limit the effectiveness of nanomaterial-based wound dressings in promoting complete tissue regeneration. To overcome these limitations, plant-derived bioactives are integrated with nanomaterials within a hydrogel cage to enhance antibacterial activity, mitigate oxidative stress and inflammation, and promote tissue regeneration. Methods: A multifunctional alginate–gelatin hydrogel incorporating silver nanoparticles and plant extracts (AG-AgNP-PE) was developed to promote scar-free wound healing, alongside a plant extract-free silver nanoparticles-loaded hydrogel for comparative evaluation of the functional contribution of plant bioactives. The biological performance of the formulated hydrogels was systematically evaluated through antioxidant, antimicrobial, and antibiofilm assays, while in vitro cytocompatibility and proregenerative activity were assessed using MTT and Alamar Blue assays, live/dead cell imaging, and a scratch-wound assay, complemented by in vivo evaluation in zebrafish embryos. Results: Pro-angiogenic activity was further investigated using the CAM model, and therapeutic efficacy was validated in an in vivo rat burn wound model through microscopic wound assessment, histopathological examination, and biochemical assays. Conclusions: Among the hydrogels, AG-AgNP-PE exhibited superior performance across all key properties, highlighting the synergistic effect of the nanomaterial combined with plant extracts within hydrogel cages and positioning it as a promising multifunctional wound dressing for rapid tissue regeneration and scar-free wound healing, suitable for advanced wound management. Full article

This study analyzed the dynamic variation in leaf ecological stoichiometry of lettuce during the whole growth period under the two different fertility levels, and explored the potential application of ecological stoichiometry theory for precise fertilization management of lettuce under the evaluated experimental condition. Taking the two critical leaf ages of 10.39 and 24.25 as dividing points, the growth process of lettuce can be divided into three stages: the initial slow growth stage—S1, mid-rapid growth stage—S2, and subsequent slow growth stage—S3. With plant growth, the contents of carbon (C) and nitrogen (N) in leaves kept increasing, while phosphorus (P) content showed a trend of rising first and then decreasing. The leaf C:N ratio declined steadily, and the C:P and N:P ratios decreased first and then increased. Most stoichiometric indicators exhibited significant differences among different growth stages (p < 0.05). Compared with the medium fertility level treatment, the aboveground biomass of lettuce under the higher fertility level treatment slightly increased, but the contents of C, N, and P in leaves all decreased, and no significant differences in various ecological stoichiometric indicators were observed between the two fertility level treatments (p > 0.05). The dynamic variation patterns of leaf C, N, and P contents and their stoichiometric ratios of the tested lettuce under the designed experimental conditions were consistent with the Homeostasis Theory and Allometric Growth Theory of ecological stoichiometry. Based on the above results, this study established ecological stoichiometric reference criteria suitable for dynamic nutrient regulation of lettuce. Collectively, the present findings not only established targeted ecological stoichiometric reference criteria for dynamic nutrient regulation of the lettuce cultivar used in the study under the tested fertility conditions, but also this research idea may be extended to nutrient regulation of other lettuce cultivars or other crop species. Full article

This study reports a comparative evaluation of natural polymeric biomaterial films impregnated with silver nanoparticles (AgNPs) synthesized using the ethyl acetate (EA) extract of Centratherum anthelminticum (CA), yielding CA-EA extract-mediated AgNPs (CA-EA-AgNPs). The biopolymeric films were solution cast and confirmed for nanoparticle impregnation using techniques such as FTIR, XRD, and FESEM-EDAX. In addition to possessing antimicrobial activity, AgNPs also act as structural modifiers. AgNPs significantly enhanced tensile strength from 19.00 ± 0.62 MPa to 24.52 ± 0.97 MPa and Young’s modulus from 106.2 ± 18.2 MPa to 143.8 ± 7.15 MPa for chitosan (CH)-based films. For agar (AA)-based films, tensile strength increased modestly from 105.31 ± 1.18 MPa to 111.81 ± 1.78 MPa, maintaining a high Young’s modulus (1411.8 MPa). The water contact angle changed from 31.5° to 49.9° and from 56.9° to 86.7° for CH and AA films, respectively. The nanocomposite films demonstrated controlled equilibrium swelling kinetics without structural disintegration. The films exhibited moderately improved antibacterial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Proteus mirabilis, yielding zones of inhibition (diameter) from 7.67 ± 0.47 mm to 10.33 ± 0.47 mm, 7.33 ± 0.47 mm to 9.67 ± 0.47 mm, and 7.67 ± 0.47 mm to 8.67 ± 0.47 mm for chitosan-based films and from 7.67 ± 0.47 mm to 11.67 ± 0.47 mm, 7.67 ± 0.47 mm to 10.67 ± 0.47 mm, and 7.33 ± 0.47 mm to 8.67 ± 0.47 mm for agar-based films, respectively, against their respective controls. The above findings demonstrate the potential of these nanoparticle-loaded biopolymer films as potent antimicrobial biomaterials for prospective wound management applications. Full article

The formation and stabilization of silver nanoparticles (AgNPs) in thin films of ionic liquids (ILs) based on long-chain alkylimidazolium cations are demonstrated in this work. IL films were prepared by vacuum thermal evaporation using the Knudsen effusion method onto ITO/glass substrates, leading to the formation of micro- and nanosized structures distributed across the surface. The investigated ILs were symmetrical dialkylimidazolium-based systems: [C₇C₇im][NTf₂], [C₈C₈im][NTf₂], and [C₁₀C₁₀im][NTf₂]. Increasing the alkyl side-chain length of the imidazolium cation resulted in larger droplet domains. AgNPs were subsequently deposited onto the IL films by sputtering. The formation of AgNPs was confirmed by scanning electron microscopy (SEM), ultraviolet (UV)–visible spectroscopy, and X-ray photoelectron spectroscopy (XPS). The results show that increasing the alkyl side-chain length promotes more effective confinement and stabilization of AgNPs, leading to improved nanoparticle formation and a narrower size distribution. The temporal stability of the Ag-containing IL films was evaluated under both air exposure and inert argon storage, revealing a strong influence of the surrounding atmosphere on nanoparticle evolution. Among the ILs studied, [C₁₀C₁₀im][NTf₂] exhibited the most favorable behavior for AgNP formation and stabilization, providing a more stable and homogeneous nanoparticle distribution over time. Full article

The emergence of antibiotic-resistant Vibrio parahaemolyticus poses a challenge to sustainable shrimp aquaculture and highlights the need for effective antibacterial alternatives. In this study, silver nanoparticles were biosynthesized using Eri silk fibroin (ESF) as both a reducing and stabilizing biopolymer. Eri silkworms can be reared on cassava leaves, an abundant agricultural by-product in Thailand, thereby supporting waste valorization and the circular bioeconomy. Optimal synthesis was achieved at an AgNO₃-to-ESF weight ratio of 1:4, 60 °C, and 4 h, yielding 82.8% ESF-AgNPs with a particle size of 10.8 ± 2.3 nm and a polydispersity index of 0.19 ± 0.01. TEM, XRD, and XPS confirmed the formation of well-dispersed metallic Ag⁰. The particles remained colloidally stable for at least four weeks. ESF-AgNPs exhibited minimum inhibitory and bactericidal concentrations of 12.5 and 25 µg/mL, respectively; inhibited biofilm formation by 52.45–99.98%; and increased intracellular reactive oxygen species generation. After 72 h, silver release reached 5.70% in deionized water and 9.30% in TSB containing 3% NaCl. Artemia franciscana survival remained 96.2% after 24 h at the MBC. These findings support ESF as a sustainable platform for producing antibacterial and antibiofilm AgNPs with a preliminary safety margin, although further in vivo efficacy and chronic-toxicity studies are required before practical application. Full article

Synthetic azo dyes are the largest class of industrial colorants having widespread application in textile, food, cosmetic, and pharmaceutical industries. Moreover, they are persistent and toxic, threatening aquatic environments as well as human health. Disperse red 1 (DR1), a mono-azo dye belonging to the disperse dye group and widely used in polyester dyeing, cosmetics, and other applications, is of particular concern due to its mutagenic potential and resistance to conventional treatment processes. The present study investigated an integrated DR1 removal strategy using thermotolerant Bacillus licheniformis Tol1 as well as its EPS-stabilized biogenic silver nanoparticles (AgNPs). With a maximum tolerable concentration of 0.5 g L⁻¹, B. licheniformis Tol1 showed a maximum decolorization of 70.86% (0.2 g L⁻¹, 55 °C). However, response surface methodology (RSM) based on the Box–Behnken design showed an actual decolorization efficiency of 73.13%. The artificial neural network (ANN) model predicted an accuracy of R² = 0.9933, confirming the robustness and reliability of the experimental findings. To enhance dye removal efficiency, Tol1 EPS-stabilized AgNPs were synthesized via a green method and characterized using UV-Vis, SEM-EDAX, TEM, AFM, FTIR, DLS and zeta potential. Characterization of AgNP confirmed the formation of spherical stable AgNPs with an average size of 19.99 ± 0.38 nm, indicating polydisperse colloids nature with moderate electrostatic stability. A sunlight/H₂O₂-assisted process (photocatalytic experiments) demonstrated DR1 decolorization (80.72 ± 1.72% within 5 h under sunlight) following pseudo-first-order kinetics (k = 0.271 h⁻¹). Furthermore, FTIR analysis confirmed the degradation of the chemical structure of DR1 through the disappearance of the characteristic azo (–N=N–) bond, indicating cleavage of the dye molecule. Overall, the present study provides a dual biological–nanotechnological approach for DR1 decolorization using single bacteria as well as its polysaccharide-stabilized AgNP, a sustainable eco-friendly future approach. However, further studies on complete mineralization, transformation products, toxicity evaluation, detailed catalyst reusability, and silver (Ag) leaching are needed to facilitate the practical implementation for wastewater treatment. Full article

Central nervous system (CNS) disorders represent a significant healthcare challenge, with aging as the primary risk factor. Current clinical management remains predominantly symptomatic, as late-stage diagnosis and the blood–brain barrier (BBB) limit therapeutic efficacy. This review synthesizes emerging innovations in neurotheranostics—integrated diagnostic and therapeutic platforms—focusing on the neurovascular unit (NVU) as a central pathogenic driver and target. Evidence indicates that NVU and BBB dysfunction are early events in Alzheimer’s, Parkinson’s, amyotrophic lateral sclerosis, and Huntington’s diseases, often preceding classic neuropathological hallmarks. The review highlights the potential of nanotechnology, engineered nanoparticles (NPs) and microRNAs (miRNAs) as precision tools for early detection and targeted CNS delivery. Additionally, it discusses the transformative impact of artificial intelligence (AI) in facilitating personalized, predictive care. Transitioning from a generic “one-pill-for-one-disease” model to a patient-centered strategy targeting early NVU alterations is essential. Integrating AI, nanotechnology and NVU-focused strategies offers a promising path toward effective, personalized disease-modifying therapies. Full article

In this work, a simple chemical- and thermal-free procedure was developed for the green synthesis of AgNPs using pomegranate (Punica granatum) peel extract as both reducing and stabilizing agents under ambient conditions. The pomegranate extract exhibited a high total phenolic content of 126.37 ± 5.29 mg GAE/g DW, indicating the abundance of bioactive phytochemicals capable of promoting nanoparticle formation. The synthesis parameters were optimized by varying reaction time and extract concentration, with the optimum conditions identified as 18 mg/mL extract concentration and 48 h reaction time based on UV–Vis analyses. The synthesized AgNPs at the optimized condition exhibited a characteristic surface plasmon resonance band at 430–440 nm and were predominantly quasi-spherical with an average particle size of 36.9 ± 14.2 nm determined by TEM. Dynamic light scattering (DLS) analysis yielded an intensity-weighted average hydrodynamic diameter of 72.5 ± 2.4 nm, while the number-weighted distribution confirmed that the suspension was predominantly composed of smaller nanoparticles that were consistent with the TEM observations. The synthesized AgNPs also exhibited a zeta potential of −33.5 ± 0.6 mV, indicating good colloidal stability. XRD and EDX analyses confirmed the formation of crystalline metallic AgNPs, while FTIR results suggested the involvement of phytochemicals in nanoparticle stabilization. The AgNPs also showed concentration-dependent antibacterial activity against E. coli and S. aureus, with MIC (MBC) values of 18.75 (37.5) and 9.375 (150) µg/mL, respectively. In addition, the cytotoxicity assessment using L929 fibroblasts yielded an IC₅₀ value of 86 µg/mL, with a selectivity index of 4.59 and 9.17 against E. coli and S. aureus, respectively, indicating an excellent degree of preferential toxicity toward bacterial cells. Full article

Porous ceramic pellets (PCPs) coated with silver nanoparticles (Ag NPs) have attracted considerable attention as surface-modified ceramic materials because they combine the structural stability of porous ceramics with the unique physicochemical properties of Ag NPs. In this work, the PCPs were prepared from local Thai clay, and Ag NPs were immobilized onto the PCP surface using cetyltrimethylammonium bromide (CTAB) as the surface immobilization. The effects of ceramic composition, reducing agents, and soaking time on the surface immobilization of Ag NPs were systematically investigated. The optimal ceramic composition consisting of 65 wt% red clay, 25 wt% ceramic powder, and 10 wt% rice husk exhibited good structural stability after soaking and a porosity of approximately 35%. Ag NPs were synthesized in situ using ascorbic acid (AA) and sodium borohydride (NaBH₄) as reducing agents, and coating performance was examined at soaking times of 6, 12, 24, and 48 h. FE-SEM observations revealed that Ag NPs synthesized using AA tended to form relatively large agglomerates, whereas NaBH₄ produced a more homogeneous nanoparticle distribution on the PCP surface. Among the investigated conditions, NaBH₄ with a soaking time of 12 h exhibited the most homogeneous nanoparticle distribution. These results suggest that CTAB-assisted surface immobilization is an effective strategy for immobilizing Ag NPs on porous ceramic substrates. The present study primarily focuses on surface immobilization behavior rather than biological performance. Full article

In this study, a simple, cost-effective, and eco-friendly approach was developed for the synthesis of AgNPs using white (Muscat Ottonel, WGPE) and red (Cabernet Sauvignon, RGPE) grape pomace extracts. The AgNPs were characterized by SEM, AFM, DLS, UV–Vis, FTIR, and XPS techniques. Their formation was initially indicated by a color change from colorless to dark brown and confirmed by the appearance of an SPR peak at 445 nm. The AgNPs are predominantly spherical with varied sizes. FTIR and XPS analyses indicated the presence of oxygen- and nitrogen-containing functional groups on the nanoparticle surface, suggesting their involvement in the reduction of Ag⁺ ions and the stabilization of the synthesized AgNPs. The biological activity of AgNPs was assessed through wheat (Triticum aestivum L.) seed priming experiments. Treatment with 25 mg/L AgNPs (WGPE) significantly enhanced seedling growth and chlorophyll content, whereas exposure to 100 mg/L AgNPs (RGPE) induced oxidative stress and negatively affected growth parameters. Furthermore, the photocatalytic activity of both AgNPs was evaluated against MB degradation under visible light irradiation. AgNPs (WGPE) showed superior photocatalytic efficiency, achieving up to 77% dye removal within 240 min and a constant rate nearly three times higher than that of AgNPs (RGPE). The photodegradation process was mainly driven by ^•OH radicals. Our results highlight the potential of biosynthesized AgNPs for agricultural applications and wastewater remediation. Full article

Nonlinear absorption (NLA) in silver nanoparticles (Ag NPs) is strongly affected by plasmonic field enhancement. However, its wavelength- and energy-dependent evolution on the red side of the surface plasmon resonance (SPR) band remains insufficiently understood. Here, we systematically investigate the NLA properties of Ag NPs using open-aperture (OA) Z-scan measurements combined with femtosecond transient absorption (TA) spectroscopy. The results show that Ag NPs exhibit saturable absorption (SA) under low excitation energies, whereas higher excitation energies induce a mixed SA/reverse saturable absorption (RSA) response. A pronounced wavelength dependence is also observed as the excitation approaches the SPR band, where nonlinear absorption gradually evolves with spectral detuning. TA measurements revealed ultrafast carrier dynamics characterized by a fast electron–phonon relaxation process (~3.3 ps) followed by a slower lattice cooling process (~46 ps). These results demonstrate that the nonlinear response is governed by the interplay between plasmonic resonance and ultrafast carrier relaxation, providing insights for the design of plasmonic nanomaterials for ultrafast nonlinear photonic applications. Full article

Hospital wastewater has begun to act as an important source of emerging contaminants, including rare earth elements (REEs), mostly lanthanides, and radiopharmaceutical residues originating from diagnostic and therapeutic nuclear medicine procedures. The increasing use of gadolinium-based contrast agents, lutetium-containing therapeutics, technetium-99m tracers, iodine-131, yttrium-90, and gallium-68 radiopharmaceuticals has raised growing concerns regarding the release of radioactive and metal-containing compounds into aquatic environments. Conventional wastewater treatment plants are often inefficient in removing these contaminants because of their high chemical stability, low environmental concentrations, and complex aqueous speciation. In this context, hybrid nanomaterials containing silver nanoparticles (AgNPs) have attracted increasing interest for both monitoring and remediation applications. AgNP-based systems exhibit unique plasmonic, catalytic, antimicrobial, and sensing properties that can be exploited in adsorption, photocatalysis, membrane filtration, electrochemical detection, and surface-enhanced Raman spectroscopy (SERS). This review critically analyzes recent advances in hospital wastewater treatment and how hybrid nanomaterials containing silver nanoparticles (AgNPs) are emerging. The review places a particular focus on contamination by REEs and radiopharmaceuticals residues, which to date, as far as we know, remains a challenging and understudied aspect, as reflected by limited publications. Full article

Although the modification of resin composites with antimicrobial agents represents a viable alternative for biofilm inhibition, these changes may compromise the optical and mechanical properties of dental restorations. This in vitro pilot study evaluated the effect of incorporating Nano-Silver Fluoride (NSF) containing 2000 ppm silver nanoparticles (AgNPs) on the microhardness and color of flowable resin composites: Vittra APS Unique Flowable (VA), Filtek Bulk Fill Flowable (FB), and Filtek Supreme Flowable (FS). The resin composites were modified by adding 1 wt%, 2 wt%, and 4 wt% NSF and compared with an unmodified group (control). NSF was characterized by UV–visible spectroscopy and transmission electron microscopy. The specimens were subjected to Vickers microhardness testing and color analysis using the CIEDE2000 (ΔE₀₀) and CIELAB (ΔE) systems. NSF incorporation had a material-dependent effect on microhardness. The VA group showed a progressive reduction in microhardness with increasing NSF additions, whereas the FS group remained unchanged up to the concentration of 2 wt%, and the FB group showed no significant reduction in microhardness at any of the tested concentrations compared with the control (p = 0.549). All resin composites exhibited clinically relevant color changes that increased with the NSF concentration, with more pronounced color changes in the VA group, whereas FB and FS did not vary significantly with the addition of different NSF concentrations. Overall, NSF mainly affected the optical properties, with esthetic limitations being the main challenge to be overcome in further studies. The FB and FS groups at 1 wt% and 2 wt% showed smaller chromatic changes than VA, without compromising microhardness, and appear promising for future investigations, including antimicrobial and cytotoxicity analyses. Full article