Search Results (1,200)

The hybrid inorganic–organic material concept plays a bold role in multifunctional materials, combining different features on one platform. Once varying properties coexist without cancelling each other on one matrix, a new type of supermaterial can be formed. This concept showed that silver nanoparticles can be embedded together with inorganic and organic surface coatings and silicon quantum dots for symbiotic antibacterial character and UV-excited visible light fluorescent features. Additionally, fluorosilane material can be coupled with this prepolymeric structure to add the hydrophobic feature, showing water contact angles around 120°, providing self-cleaning features. Optical properties of the components and the final material were investigated by UV-Vis spectroscopy and PL analysis. Atomic investigations and structural variations were detected by XPS, SEM, and EDX atomic mapping methods, correcting the atomic entities inside the coating. FT-IR tracked surface features, and statistical analysis of the quantum dots and nanoparticles was conducted. Multifunctional final materials showed antibacterial properties against E. coli and S. aureus, exhibiting self-cleaning features with high surface contact angles and visible light fluorescence due to the silicon quantum dot incorporation into the sol-gel-produced nanocomposite hybrid structure. Full article

We utilized silver nanoparticles synthesized from bitter melon (Momordica charantia) extracts for testing against the common agricultural pathogen Escherichia coli. The synthesized nanoparticles were characterized and confirmed as silver nanoparticles by using ultraviolet spectroscopy, Fourier transform infrared spectroscopy, and scanning electron microscopy analysis. The results show that AgNPs were effective against E. coli ATCC25922 strain. The AgNPs had an increased potency against the E. coli strain in optimum culture media compared to silver ions alone. AgNP-treated cultures achieved a kill percentage of 100% in less incubation time and at a lower dosage than those treated with silver ions alone. The powder form of the AgNPs also showed remarkable potency against E. coli in solution. Based on these findings, the current method is suitable for the industrial-scale production of AgNPs from a commonly available edible plant with known medicinal benefits in the fight against foodborne pathogens, including antibiotic-resistant strains. Full article

Developing multifunctional wound dressings with excellent mechanical properties, strong tissue adhesion, and efficient antibacterial activity is crucial for promoting wound healing. This study prepared a novel nanocomposite hydrogel dressing based on sodium alginate-polyacrylic acid dual crosslinking networks, incorporating tannic acid-coated cellulose nanocrystals (TA@CNC) and in-situ reduced silver nanoparticles for multifunctional enhancement. The rigid CNC framework significantly improved mechanical properties (elastic modulus of 146 kPa at 1 wt%), while TA catechol groups provided excellent adhesion (36.4 kPa to pigskin, 122% improvement over pure system) through dynamic hydrogen bonding and coordination interactions. TA served as a green reducing agent for uniform AgNPs loading, with CNC negative charges preventing particle aggregation. Antibacterial studies revealed synergistic effects between TA-induced membrane disruption and Ag⁺-triggered reactive oxygen species generation, achieving >99.5% inhibition against Staphylococcus aureus and Escherichia coli. The TA@CNC-regulated porous structure balanced swelling performance and water vapor transmission, facilitating wound exudate management and moist healing. This composite hydrogel successfully integrates mechanical toughness, tissue adhesion, antibacterial activity, and biocompatibility, providing a novel strategy for advanced wound dressing development. Full article

Rosemary (Salvia rosmarinus) is renowned for its antioxidant, anti-inflammatory, and antihyperglycemic properties, largely attributed to its rich phytochemical profile. This study evaluates the potential of metabolites from Pseudomonas shirazensis NFV3, formulated in silver nanoparticles (AgNPs), to enhance the bioactivity of rosemary extracts in postharvest applications. Rosemary stems were treated with AgNPs coated with bacterial metabolites (NP), bacterial cells, or metabolites (LM), and the extracts’ phytochemical composition and bioactivities were assessed. HPLC and HPLC–MS analyses revealed that the NP treatment induced significant metabolic remodeling, particularly upregulating rosmarinic acid and selected triterpenes (ursolic and betulinic acids), while reducing carnosic acid levels. NP-treated extracts exhibited significantly enhanced inhibition of cyclooxygenase (COX-1 and COX-2), indicating improved anti-inflammatory potential. The α-glucosidase inhibition and antioxidant activity (DPPH assay) of the extracts were not substantially altered, suggesting the selective enhancement of pharmacological functions. These findings demonstrate that nanoparticle-based elicitation selectively remodels secondary metabolism in rosemary, improving extract quality and bioactivity. This strategy offers a novel, sustainable tool for optimizing plant-based therapeutics in the phytopharmaceutical industry. Full article

In this study, we report the development of a novel magnetized coal fly ash-supported nano-silver composite (AgNPs/MCFA) for dual-functional applications in wastewater treatment: the efficient degradation of methyl orange (MO) dye and broad-spectrum antibacterial activity. The composite was synthesized via a facile impregnation–reduction–sintering route, utilizing sodium citrate as both a reducing and stabilizing agent. The AgNPs/MCFA composite was systematically characterized through multiple analytical techniques, including Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and vibrating sample magnetometry (VSM). The results confirmed the uniform dispersion of AgNPs (average size: 13.97 nm) on the MCFA matrix, where the formation of chemical bonds (Ag-O-Si) contributed to the enhanced stability of the material. Under optimized conditions (0.5 g·L⁻¹ AgNO₃, 250 °C sintering temperature, and 2 h sintering time), AgNPs/MCFA exhibited an exceptional catalytic performance, achieving 99.89% MO degradation within 15 min (pseudo-first-order rate constant k_a = 0.3133 min⁻¹) in the presence of NaBH₄. The composite also demonstrated potent antibacterial efficacy against Escherichia coli (MIC = 0.5 mg·mL⁻¹) and Staphylococcus aureus (MIC = 2 mg·mL⁻¹), attributed to membrane disruption, intracellular content leakage, and reactive oxygen species generation. Remarkably, AgNPs/MCFA retained >90% catalytic and antibacterial efficiency after five reuse cycles, enabled by its magnetic recoverability. By repurposing industrial waste (coal fly ash) as a low-cost carrier, this work provides a sustainable strategy to mitigate nanoparticle aggregation and environmental risks while enhancing multifunctional performance in water remediation. Full article

The integration of nanotechnology and green synthesis strategies provides innovative solutions in biomedicine. This study focuses on the biofabrication of silver nanoparticles (AgNPs) using Corynespora smithii, an endophytic fungus isolated from Bergenia ciliata. The eco-friendly synthesis process employed fungal extracts as reducing and stabilizing agents thereby minimizing the need for hazardous chemicals. The AgNPs demonstrated strong potent biological activities, showcasing significant antioxidant, antibacterial, and anticancer properties. The antibacterial efficacy was demonstrated against various Gram-positive and Gram-negative bacteria, while cytotoxicity on the A549 lung cancer cell line revealed an IC₅₀ value of 10.46 µg/mL. A molecular docking analysis revealed interactions between the major bioactive compound, dimethylsulfoxonium formylmethylide, and the pathogenic proteins, Staphylococcus aureus and Salmonella typhi, displaying moderate binding affinities. Furthermore, the ADME analysis of dimethylsulfoxonium formylmethylide indicated favourable pharmacokinetic properties, including high gastrointestinal absorption, minimal lipophilicity, and low potential for drug–drug interactions, making it a promising candidate for oral drug formulations. These findings further support the compound’s suitability for biomedical applications. This research emphasizes the potential of C. smithii as a sustainable source for synthesizing bioactive nanoparticles, paving the way for their application in developing novel therapeutic agents. This study highlights the significance of harnessing endophytic fungi from medicinal plants for sustainable nanotechnology advancements. Full article

In the present study, for the first time, a biodegradable and non-toxic polyphosphoramidate glycohydrogel (PPAGHGel) was prepared by crosslinking a polyphosphoramidate glycoconjugate (PPAG) with hexamethylene diisocyanate (HMDI) under mild conditions. Poly(oxyethylene H-phosphonate) (POEHP) was used as a precursor and was converted into PPAG via the Staudinger reaction with glucose-containing azide (2-p-azidobenzamide-2-deoxy-1,3,4,6-tetra-O-trimethylsilyl-α-D-glucopyranose). Then, crosslinking of PPAG was performed to yield PPAGHGel, which was thoroughly characterized. The gel showed a gel fraction of 83%, a swelling degree of 1426 ± 98%, and G″ = 1560 ± 65 Pa. The gel was fully degraded by alkaline phosphatase (400 U/L, pH 9) in 19 days, while hydrolytically, up to 52% degradation was observed under similar conditions. Multivalent studies of the obtained hydrogel with lectin–Concanavalin A were performed. PPAGHGel binds 92% of Concanavalin A within 24 h and the complex remains stable until the amount of glucose reaches 0.3 mM. PPAGHGel acts as a stabilizer for silver nanoparticles (12 nm). SEM shows pores measuring 10 µm (surface) and 0.1 mm (interior) with capillary channels, confirming the gel’s suitability for biosensors, drug delivery, or wound dressings. The cytotoxic (IC50) and cell-adhesive properties of the obtained hydrogel were investigated on human cell lines (HeLa). Antibacterial activity tests were also performed with gel containing silver nanoparticles against skin-associated pathogenic bacteria. The results show that PPAGHGel possesses excellent biocompatibility, non-adhesive properties and antibacterial activity. Full article

Nanoparticles (NPs) synthesised through biogenic routes have emerged as a sustainable and innovative platform for biomedical applications such as antibacterial, anticancer, antiviral, anti-inflammatory, drug delivery, wound healing, and imaging diagnostics. Among these, silver nanoparticles (AgNPs) have attracted significant attention due to their unique physicochemical properties and therapeutic potential. This review examines the biogenic synthesis of AgNPs, focusing on microbial, plant-based, and biomolecule-assisted approaches. It highlights how reaction conditions, such as pH, temperature, and media composition, influence nanoparticle size, shape, and functionality. Particular emphasis is placed on microbial synthesis for its eco-friendly and scalable nature. The mechanisms of AgNP formation and their structural impact on biomedical performance are discussed. Key applications are examined including antimicrobial therapies, cancer treatment, drug delivery, and theranostics. Finally, the review addresses current challenges, such as reproducibility, scalability, morphological control, and biosafety, and outlines future directions for engineering AgNPs with tailored properties, paving the way for sustainable and effective next-generation biomedical solutions. Full article

Salmonella enterica serovar Typhimurium (S. Typhimurium) is an intracellular pathogen capable of surviving and replicating within macrophages, which causes foodborne diseases such as gastroenteritis. To develop a strategy against intracellular bacteria in macrophages, we designed silver-loaded biodegradable polymer nanoparticles functionalized with S. Typhimurium membrane vesicles (MVs). Silver nanoparticles (Ag NPs) were initially encapsulated within biodegradable poly(lactic-co-glycolic) nanoparticles (Ag-P NPs), which were then surface-modified with polyethyleneimine to form Ag-PP NPs. These were subsequently fused with S. Typhimurium MVs via a sonication method to generate Ag-PP@MV NPs. The resulting MV-coated nanoparticles displayed a similar protein profile to that of native MVs and exhibited antibacterial activity against intracellular S. Typhimurium. Notably, the enhanced cellular uptake of the MV-modified NPs contributed to their intracellular bactericidal efficacy. This study highlights MV modification as a promising strategy to improve NP delivery to macrophages for treating persistent intracellular infections. Full article

This study investigates the antioxidant, antimicrobial, and antitumor activities of Taraxacum officinale (Dandelion) and Artemisia annua (Sweet Wormwood) extracts, along with their role in the green synthesis of gold (AuNPs) and silver nanoparticles (AgNPs). Bioreduction was achieved using aqueous and ethanolic extracts (100 mg/mL), enabling solvent-dependent comparisons. Nanoparticles were characterized using ultraviolet–visible spectroscopy (UV–Vis), fluorescence spectroscopy, scanning electron microscopy (SEM), dynamic light scattering (DLS), high-resolution transmission electron microscopy (HRTEM), and zeta potential analysis. Each technique revealed complementary aspects of nanoparticle morphology, size, and stability, with UV–Vis indicating aggregation states and DLS confirming solvent-related size variation even at 3–5% ethanol. Gold nanoparticles synthesized from Dandelion showed strong antibacterial activity against Staphylococcus aureus, while silver nanoparticles from both plants were effective against Escherichia coli. Cytotoxicity assays indicated that silver nanoparticles obtained from ethanolic Dandelion extract containing 3% ethanol in aqueous solution (AgNPsE_ETOH3%-D) significantly reduced LoVo (p = 4.58 × 10⁻³) and MDA-MB-231 (p = 7.20 × 10⁻⁵) cell viability, with high selectivity indices (SI), suggesting low toxicity toward normal cells. Gold nanoparticles synthesized from aqueous Dandelion extract (AuNPsEaq-D) also showed favorable SI values (2.16 for LoVo and 8.41 for MDA-MB-231). Although some formulations demonstrated lower selectivity (SI < 1.5), the findings support the therapeutic potential of these biogenic nanoparticles. Further in vivo studies and pharmacokinetic evaluations are required to validate their clinical applicability. Full article

At emergency sites, bacteria in the environment can cause secondary wound infections. Timely treatment of infected wounds can improve the prognosis. In this study, we designed a closed-loop system for real-time wound infection monitoring and electronically controlled drug release, enabling rapid and stable deployment at disaster sites. Multilayer screen-printed electrodes were developed to detect uric acid (UA), pH, and temperature biomarkers. The electrode’s outermost layer was shielded by a zwitterionic conductive hydrogel (Gel) to prevent environmental interference and achieve systematic antibacterial protection through in situ reduction of silver nanoparticles (AgNPs) on its surface. For rapid and efficient drug delivery, amikacin (Ami) loaded cationic liposomes (Lipo) embedded in the zwitterionic conductive hydrogel (Gel-Lipo@Ami) were integrated as the core therapeutic carrier. This closed-loop system provides timely infection detection and enables in situ treatment during emergency rescues. Full article

Continued efforts have been made to enhance the antibacterial properties of root canal sealers by adding antimicrobial agents to them. This study aims to investigate the antibacterial effect of 0.15% silver nanoparticles (NAg) and 5% dimethylaminohexadecyl methacrylate (DMAHDM) when added to EndoSequence Bioceramic (BC) sealer against Enterococcus faecalis (E. faecalis) biofilm and their impact on its physical properties (flowability and film thickness). Four root canal sealers were tested for flow and film thickness properties, as well as against antibiofilm of E. faecalis-impregnated dentin discs, as follows: group 1: EndoSequence BC sealer only; group 2: EndoSequence BC sealer + 0.15% NAg; group 3: EndoSequence BC sealer + 5% DMAHDM; and group 4: EndoSequence BC sealer + 0.15% NAg + 5% DMAHDM. The findings show that all groups had flow and film thickness values that were in accordance with the ISO requirements. Combining 0.15% NAg and 5% DMAHDM in EndoSequence significantly reduced colony-forming unit (CFU) counts by approximately 5 logs. The combination of NAg and DMAHDM offers a promising strategy for developing endodontic sealers with improved antimicrobial properties and acceptable physical performance. Full article

Honey, propolis or royal jelly are considered natural remedies with therapeutic properties since antiquity. Many papers explore the development of antimicrobial biomaterials based on individual bee products, but there is a lack of studies on their synergistic effects. Combining honey, propolis and royal jelly with silver nanoparticles in a biopolymer matrix offers a synergistic strategy to combat antibiotic-resistant bacterial infections. This approach supports progress in wound healing, soft tissue engineering and other domains where elimination of the microorganisms is needed like food packaging. In this study we have obtained antimicrobial films based on bee products and silver nanoparticles (AgNPs) incorporated in an alginate–chitosan blend. The novel biomaterials were analyzed by UV-Vis, fluorescence and FTIR spectroscopy or microscopy, SEM and thermal analysis. Antibacterial tests were conducted against both Gram-positive and Gram-negative bacteria, while the antifungal properties were tested against Candida albicans. The diameters for growth inhibition zones were up to 10 mm for bacterial strains and 8 mm for the fungal strain. Additionally, cytotoxicity assays were performed to evaluate the biocompatibility of the materials, the results indicating that the combination of honey, propolis, royal jelly and AgNPs does not produce synergistic toxicity. Full article

Silver nanoparticles (AgNPs), lauded for their unique antibacterial and physicochemical attributes, are proliferating across industrial sectors, raising concerns about their environmental fate, in aquatic systems. While “green” synthesis offers a sustainable production route with reduced chemical byproducts, the safety of these AgNPs for aquatic fauna remains uncertain due to nanoparticle-specific effects. Conversely, mast cells play crucial roles in fish immunity, orchestrating innate and adaptive immune responses by releasing diverse mediators and recognizing danger signals. Goblet cells are vital for mucosal immunity and engaging in immune surveillance, regulation, and microbiota interactions. The interplay between these two cell types is critical for maintaining mucosal homeostasis, is central to defending against fish diseases and is highly responsive to environmental cues. This study investigates the acute dermatotoxicity of environmentally relevant AgNP concentrations (0, 0.031, 0.250, and 5.000 μg/L) on zebrafish epidermis. A 96 h assay revealed a biphasic response: initial mucin hypersecretion at lower AgNP levels, suggesting an early stress response, followed by a concentration-dependent collapse of mucosal integrity at higher exposures, with mucus degradation and alarm cell depletion. A rapid and generalized increase in epidermal mucus production was observed across all AgNP exposure groups within two hours of exposure. Further mechanistic insights into AgNP-induced toxicity were revealed by concentration-dependent alterations in goblet cell dynamics. Lower AgNP concentrations initially led to an increase in both goblet cell number and size. However, at the highest concentration, this trend reversed, with a significant decrease in goblet cell numbers and size evident between 48 and 96 h post-exposure. The simultaneous presence of neutral and acidic mucins indicates a dynamic epidermal response suggesting a primary physical barrier function, with acidic mucins specifically upregulated early on to enhance mucus viscosity, trap AgNPs, and inhibit pathogen invasion, a clear defense mechanism. The subsequent reduction in mucin-producing cells at higher concentrations signifies a critical breakdown of this protective strategy, leaving the epidermis highly vulnerable to damage and secondary infections. These findings highlight the vulnerability of fish epidermal defenses to AgNP contamination, which can potentially compromise osmoregulation and increase susceptibility to threats. Further mechanistic research is crucial to understand AgNP-induced epithelial damage to guide sustainable nanotechnology. Full article

The antimicrobial activity of silver nanoparticles (AgNPs) makes them a valuable tool in various industries. Recently, biosynthesis has become the preferred method for nanoparticle synthesis, and among organisms that can be used as AgNP producers, filamentous fungi have attracted the greatest interest. In particular, wood decay fungi are considered promising candidates for AgNP biosynthesis. Biogenic AgNPs have been proven to have strong antibacterial potential and antifungal activity. The aim of this study was to evaluate the antifungal potential of AgNPs synthesized using the brown-rot decay fungus Gloeophyllum striatum DSM 9592 against four pathogenic fungal strains: Candida albicans, Malassezia furfur, Aspergillus flavus and Aspergillus fumigatus. Moreover, changes in the tested strains’ lipidome and cell membrane properties induced by the presence of AgNPs were investigated. The results revealed that the obtained AgNPs exerted fungistatic activity against all the strains tested. M. furfur, with a MIC value of 0.39 μg/mL obtained for all AgNP types, was found to be the most susceptible to the action of AgNPs. The lipidomic analysis revealed that the presence of AgNPs caused an increase in cell membrane fluidity in both A. flavus and C. albicans, and the mechanisms of response to AgNPs differed between the tested strains. Full article