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Carica papaya seeds were used in this research for the synthesis of AgNPs. The production of silver nanoparticles was characterized using UV–Vis spectroscopy, FTIR, XRD and SEM-EDX analysis. The antibacterial activity of the prepared AgNPs was evaluated by the Kirby–Bauer disc diffusion method with the antibacterial activity of different compounds against Bacillus aerogenes. UV–Vis spectral peaks are found at 8–18 nm. SEM and TEM analysis revealed several spherical structures between 10 nm and 50 nm. XRD analysis also confirmed its 50 nm size. Experimental data revealed that AgNPs inhibited bacterial growth. This study shows that papaya seed extract contributes to the bioreduction and stabilization of the synthesized silver nanoparticles. [ABSTRACT FROM AUTHOR]

The present study focused on evaluating the antibacterial properties, radical scavenging, and photocatalytic activities of Centaurea behen-mediated silver nanoparticles (Cb-AgNPs). The formation of Cb-AgNPs was approved by UV–Vis spectrometry, Fourier-transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy (SEM), energy dispersive X-ray and X-ray diffraction. The results showed that the obtained AgNPs have a maximum absorbance peak at 450 nm with spherical morphology and an average size of 13.03 ± 5.8 nm. The catalytic activity of the Cb-AgNPs was investigated using Safranin O (SO) solution as a cationic dye model. The Cb-AgNPs performed well in the removal of SO. The coupled physical adsorption/photocatalysis reaction calculated about 68% and 98% degradation of SO dye under solar irradiation. The Cb-AgNPs inhibited the growth of gram-negative or positive bacteria strains and had excellent DPPH radicals scavenging ability (100% in a concentration of 200 µg/ml) as well as a good effect on reducing coagulation time (at concentrations of 200 and 500 µg/mL reduced clotting time up to 3 min). Considering the fact that green synthesized Cb-AgNPs have antioxidant and antibacterial properties and have a good ability to reduce coagulation time, they can be used in wound dressings. As well as these NPs with good photocatalytic activity can be a suitable option for degrading organic pollutants. [ABSTRACT FROM AUTHOR]

In this study, we present a one‐pot synthetic approach for the preparation of metal oxide nanocomposites. Our investigation combines various analytical techniques, including FTIR, XRD, UV‐vis DRS, PL, XPS, SEM, EDX, and XANES, to comprehensively identify heterogeneous structures: SnO2‐CuO, CuO‐SnO2, NiO‐TiO2, and TiO2‐NiO. These metal oxide‐linked semiconductor solids serve as catalysts for dye photodegradation and exhibit remarkable biological activity. Our research is centered on exploring the photocatalytic potential of SnO2‐CuO nanocomposites while emphasizing the optimization of their photocatalytic and biological activities. This optimization is achieved through the careful incorporation of an ideal quantity of SnO2, as confirmed by EDX data, which reveals the composition as follows: O: 78.58 weight percent (0.525 keV), Cu: 12.61 weight percent (0.954 keV), and Sn: 8.81 weight percent (0.400 keV). Notably, under direct sunlight irradiation, the degradation efficiency of Rhodamine B dye surpasses that of pristine CuO, SnO2, TiO2, and NiO nanoparticles. Additionally, we explore the antimicrobial properties of these prepared samples at varying concentrations (50, 100, and 150 μl) against the pathogenic bacterium Staphylococcus aureus. Our findings highlight their effectiveness as antimicrobial agents. This research offers a promising method for developing highly active metal‐oxide‐linked nanomaterials, suitable for efficiently removing organic dye contaminants from water systems and showing great potential in antimicrobial applications. [ABSTRACT FROM AUTHOR]

Pomegranate waste poses an environmental challenge in Arequipa. Simultaneously, interest in sustainable materials like natural rubber latex (NRL) is growing, with Peruvian communities offering a promising source. This study explores the green synthesis of silver nanoparticles (AgNPs) using pomegranate peel extract and their incorporation into NRL nanofibers for enhanced functionalities. An eco-friendly process utilized silver nitrate and pomegranate peel extract as a reducing and capping agent to synthesize AgNPs. The resulting AgNPs and NRL/AgNPs nanofibers were characterized using imaging and spectroscopic techniques such as UV-vis, TGA, FTIR, XRD, Raman, SEM, and DLS. Green-synthesized AgNPs were spherical and crystalline, with an average diameter of 59 nm. They showed activity against K. pneumoniae, E. coli, B. cereus, and S. aureus (IC50: 51.32, 4.87, 27.72, and 69.72 µg/mL, respectively). NRL and NRL/AgNPs nanofibers (300–373 nm diameter) were successfully fabricated. The composite nanofibers exhibited antibacterial activity against K. pneumoniae and B. cereus. This study presents a sustainable approach by utilizing pomegranate waste for AgNP synthesis and NRL sourced from Peruvian communities. Integrating AgNPs into NRL nanofibers produced composites with antimicrobial properties. This work has potential applications in smart textiles, biomedical textiles, and filtration materials where sustainability and antimicrobial functionality are crucial. [ABSTRACT FROM AUTHOR]

Metal and metal oxide nanostructured materials have been chemically and physically characterized and tested concerning methylene blue (MB) photoremoval and UV antibacterial activity against Escherichia coli and Staphylococcus aureus. In detail, silver nanoparticles and commercial BaTiO3 nanoparticles were modified to obtain nanocomposites through sonicated sol–gel TiO2 synthesis and the photodeposition of Ag nanoparticles, respectively. The characterization results of pristine nanomaterials and synthetized photocatalysts revealed significant differences in specific surface area (SSA), the presence of impurities in commercial Ag nanoparticles, an anatase phase with brookite traces for TiO2-based nanomaterials, and a mixed cubic–tetragonal phase for BaTiO3. Silver nanoparticles exhibited superior antibacterial activity at different dosages; however, they were inactive in the photoremoval of the dye. The silver–TiOx nanocomposite demonstrated an activity in the UV photodegradation of MB and UV inhibition of bacterial growth. Specifically, TiO2/AgNP (30–50 nm) reduced growth by 487.5 and 1.1 × 103 times for Escherichia coli and Staphylococcus aureus, respectively, at a dose of 500 μg/mL under UV irradiation. [ABSTRACT FROM AUTHOR]

AbstractThe green synthesis of metal nanoparticles with curcumin which is a compound with antibiotic effects, was considered for the synthesis of metal nanoparticles. Gold and silver nanoparticles were synthesized with an average diameter of 19.8 ± 6.2 nm and 29.8 ± 6.4 nm respectively. Both particles represent stability in the physiological environment and after a series of washing procedures to remove unreacted precursors. The antimicrobial efficacy of the synthesized nanoparticles was investigated in different techniques such as disk diffusion, agar well diffusion, minimum inhibitory concentration, and minimum bactericidal concentration tests. The results of both curcumin-coated metal nanoparticles in the disk diffusion test were negative. However, in the agar dilution and MIC tests of antibacterial effect of both nanoparticles on the tested bacteria was observed. The silver nanoparticles had an inhibitory effect on all selected bacteria in the agar dilution (8-256 µg/ml). However, gold nanoparticles had a lower inhibitory effect on the growth of some of the selected bacteria (64-512 µg/ml). In conclusion, silver nanoparticles were more effective than gold nanoparticles in most of the investigated methods. [ABSTRACT FROM AUTHOR]

In this study, we report the growth of surfactant‐free silver nanoparticles (NPs) on cotton through a facile chemical reduction method, iteratively applied to gradually increase and control the concentration of silver NPs. Our substrates showed enhanced performance in surface enhanced Raman spectroscopy (SERS), catalytic, and antibacterial properties, all attributable to the high concentration of NPs on the cotton and their surfactant‐free nature. While the antibacterial properties improve with increasing growth cycles, SERS and catalytic properties first increase from the first to fourth growth cycles and then decrease for the fifth growth cycle. For substrate with optimum deposition for SERS, rhodamine 6G (R6G) analyte down to nanomolar concentrations were detectable, with a linear correlation of intensity versus concentration and exhibit excellent uniformity in the SERS signal. Furthermore, the catalytic activity of our substrates against the degradation of methyl orange (MO) was impressive with a rate constant of 0.0866 min−1 for the first growth cycle, which increased by ~3.4‐fold to 0.2979 min−1 for the fourth growth cycle. Finally, the substrates showed excellent antibacterial activity towards both Gram‐negative (E. coli) and Gram‐positive (S. aureus) bacteria. For both bacteria, the zone of inhibition increased with increasing growth cycles. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) were synthesized using the leaf extract of Ocimum basilicum, a medicinal plant, as a reducing agent. Characterization of the particles was done by UV-visible extinction spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and powder X-ray diffraction (PXRD) studies. The shapes of particles are spherical to quasi-spherical. Diffraction patterns from characteristic crystallographic planes observed in PXRD and concentric rings with bright intermittent dots observed in selected area x-ray diffraction (SAED) confirm that the silver in their nanoparticles is being crystallized into a face-centered cubic (FCC) structure. The average particle size worked out using PXRD data and the maximum of particle size distribution with respect to TEM analysis are 16 and 20 nm, respectively. Antibacterial efficacy of the synthesized AgNPs against the spreading of gram-negative bacteria, Escherichia coli and gram-positive bacteria, Staphylococcuus aureus were determined in terms of their minimum inhibitory concentration (MIC) in nutrient agar media, and the results were compared with that shown by ciprofloxacin, a reference substance. The MICs of the AgNP solutions synthesized from O. basilicum were 9.00 x 10-5 g/ mL against the spread of E. coli and 1.125 x 10-4 g/mL against S. aureus. The antibacterial efficacy determined against E. coli, in the adopted procedure, of the AgNPs synthesized using the water extract of the leaf sample of O. basilicum is superior to that exhibited by ciprofloxacin. [ABSTRACT FROM AUTHOR]

Summary: The biological synthesis of functionalised nanoparticles using plant materials is considered more cost‐effective and eco‐friendly than chemical and physical methods. Hence, this study demonstrated the synthesis of silver nanoparticles (AgNPs) using Houttuynia cordata Thunb rhizome (HCR). The extract, prepared with distilled water, provided the required phytochemical components, such as flavonoids, terpenoids, phenols, proteins and other essential bio‐reducing agents. The AgNPs were exposed to reaction conditions, such as temperatures, pH values and AgNO3 concentrations, to identify the optimum synthesis condition and explore their impacts on particle size and antibacterial action against Gram‐positive (Staphylococcus aureus) and Gram‐negative (Salmonella enterica and Shigella dysenteriae) foodborne pathogens. The formation of AgNPs was indicated by specific surface plasmon resonance (SPR) intensity at 440–450 nm and colour changes under different reaction conditions. The structure and size distribution characterised by SEM and TEM revealed that the AgNPs exhibited a spherical‐shaped structure with irregular contours, regular distribution and aggregation. Although the average particle size ranged from 2 to 100 nm, relatively smaller sizes were detected at 10 mM (54.30), 80 °C (49.50 nm) and pH 6 (60.16 nm) conditions. The FTIR spectrum and EDX spectral signals affirmed the presence of reducing and stabilising agents in HCR extract, following the reduction of AgNPs from Ag+ to Ag0. AgNPs also exhibited excellent antibacterial activity against S. aureus, S. enterica and Sh. dysenteriae, indicating a broad spectrum for various applications in the food and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

The use of traditional plants has been tremendously increased due to their higher biological impact, minimal side effects, and comparatively low cost. Moreover, the emergence of antibacterial resistance is also shifting the scientific community to reconsider herbal remedies which provide relatively safer, cheap and biologically tolerable solutions. The present research was designed to fabricate the Mentha spicata conjugated silver nanoparticles (Me-AgNPs). Furthermore, the assessment of the bactericidal potential of Me-AgNPs against various bacterial strains was another motive behind this study. Fabricated NPs were characterized with the help of the UV-Visible spectrophotometric analysis, Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM). Me-AgNPs showed a significant zone of inhibition (23 ± 0.2 mm) at 8 mg/mL against Staphylococcus aureus and a 4.0 ± 0.2 mm zone of growth inhibition at 2 mg/mL against Aeromonas veronii. The stability of Me-AgNPs was assessed at various pH (4, 7 and 11) and temperatures (25 °C, 4 °C, 37 °C, 75 °C). The significant zones of inhibition (11.3 ± 0.3 mm, 8.3 ± 0.3mm, 14.3 ± 0.3 mm, and 7.6 ± 0.2 mm) were observed at pH 11 against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Klebsiella pneumoniae, respectively. Growth inhibition zones (14.0 ± 0.5 mm and 13.0 ± 0.5 mm) were also determined against B. subtilis and S. aureus at 25 °C. DPPH bioassay was conducted to find the antioxidant properties of Me-AgNPs. The highest (38.66 ± 0.2%) free radical scavenging activity was shown by Me-AgNPs at 4 mg/mL. Present study results concluded that biogenic Me-AgNPs have bactericidal as well as anti-oxidative potential. Moreover, these green synthesized Me-AgNPs could maintain their potency and stability at a wide range of pH and temperature. [ABSTRACT FROM AUTHOR]

In recent years, there has been an increasing interest in the green synthesis of metallic nanoparticles, mostly because of the evident limitations associated with chemical and physical methods. Green synthesis, commonly referred to as "biogenic synthesis," is seen as an alternative approach to produce AgNPs (silver nanoparticles). The current work focuses on the use of Asterarcys sp. (microalga) for biological reduction of AgNO3 to produce AgNPs. The optimal parameters for the reduction of AgNPs were determined as molarity of 3 mM for AgNO3 and an incubation duration of 24 h at pH 9, using a 20:80 ratio of algal extract to AgNO3. The biosynthesized Ast-AgNPs were characterised using ultraviolet–visible spectroscopy (UV–Vis), zeta potential, scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and high-resolution transmission electron microscopy (HR-TEM) with selected area electron diffraction (SAED) patterns. The nanoparticles exhibited their highest absorption in the UV–visible spectra at 425 nm. The X-ray diffraction (XRD) investigation indicated the presence of characteristic peaks at certain angles: 38.30° (1 1 1), 44.40° (2 0 0), 64.64° (2 2 0), and 77.59° (3 1 1) according to the JCPDS file No. 04-0783. Based on SEM and TEM, the Ast-AgNPs had an average size of 35 nm and 52 nm, respectively. The zeta potential was determined to be − 20.8 mV, indicating their stability. The highest antibacterial effectiveness is shown against Staphylococcus aureus, with a zone of inhibition of 25.66 ± 1.52 mm at 250 μL/mL conc. of Ast-AgNPs. Likewise, Ast-AgNPs significantly suppressed the growth of Fusarium sp. and Curvularia sp. by 78.22% and 85.05%, respectively, at 150 μL/mL conc. of Ast-AgNPs. In addition, the Ast-AgNPs exhibited significant photocatalytic activity in degrading methylene blue (MB), achieving an 88.59% degradation in 120 min, revealing multiple downstream applications of Ast-AgNPs. [ABSTRACT FROM AUTHOR]

Polymer-based sponges loaded with antibacterial agents are potential wound dressings ideal for treating bacteria-infected wounds. Gelatin/poly (ethylene glycol) (PEG) sponge-based wound dressings loaded with metronidazole and Ag nanoparticles with different degrees of cross-linking were prepared, and their capability to treat infected wounds in vitro was evaluated. The degree of cross-linking of the sponges varied, and the porosity of the sponges was in the range of 15.64–91.10%. The amount of gelatin used to prepare the sponges influenced the porosity of the sponges. The sponges displayed an initial burst drug release of metronidazole followed by a sustained release profile. The sponges exhibited considerable antibacterial activity against Gram-positive and Gram-negative bacteria. The % cell viability of the sponges was in the range of 71.17–86.10%, indicating distinguished biocompatibility. The in vitro experiment showed that the sponge loaded with metronidazole, SAM2%, displayed a significant reduction of 66.68% in the scratch area compared to the sponge loaded with a combination of silver nanoparticles and metronidazole with a closure rate of 46.61% at 96 h. The promising features of the sponges indicate that they are potential wound dressings for treating infected wounds. [ABSTRACT FROM AUTHOR]

This study defined a facile, inexpensive, and benign method to fabricate silver nanoparticles (AgNPs) using Tradescantia pallidum var. purpurea aqueous leaves extract for the first time. A UV–vis spectrum showed that the evaluated extract was promising for green synthesis of the SNP, with the highest peak of absorption between 450 and 550 nm. The phytochemicals present in the plant extract acts as capping and stabilization agent were confirmed by FTIR analysis. EDX proved the presence of Ag while SEM confirmed the AgNPs with the spherical shape. TEM revealed the average particle size was 23 nm. Additionally, AgNPs exhibited significant antibacterial activity and turbidimetry analysis showed MIC and MBC was in range of 25–100 µg/mL against both Gram positive and Gram-negative bacteria in Luria Bertani broth cultures. The AgNPs exhibited potent antibacterial activity against gram-positive bacteria, with a ZOI of 12 ± 0.25 mm produced against BacillusB subtilis showed the largest zones of inhibition, which were greater than the positive control (cefotaxime). The MIC values were 50 µg/mL for Pseudomonas aeruginosa, 25 µg/mL for Staphylococcus aureus and Escherichia coli, and 100 µg/mL for B. subtilis, confirming their significant antibacterial action. AgNPs inhibited the DDPH free radical scavenging activity with an IC50 = 91.87 µg/mL. It is believed that these AgNPs play a crucial role in determining the therapeutic potential of T. pallida due to their biological efficacy. [ABSTRACT FROM AUTHOR]

Yttrium oxide (Y2O3) is a promising rare-earth compound that is rarely studied. This study reports on the synthesis, structural, morphological, optical and antimicrobial properties of Y2O3 nanoparticles (NPs) synthesized using Agathosma betulina leaf extract. XRD pattern indicated that the crystalline phase was achieved for the sample calcined at 5 0 0 ∘ C with body-centered cubic symmetry. SEM and TEM images of Y2O3 nanopowder showed the nearly spherical morphology of agglomerated NPs with an average diameter of 13 nm. Optical properties revealed that the bandgap of Y2O3 NPs (∼ 5. 6 7 eV) has been increased compared with the bulk Y2O3 (∼ 5. 5 eV). Moreover, the antimicrobial activity was also evaluated against gram-positive and gram-negative bacteria of clinical interest. Results demonstrated that the synthesized Y2O3 NPs exhibited higher bacteriostatic effects against gram-negative bacterial strains due to their thin cell wall structure. These results show that the synthesized Y2O3 NPs are suitable for antibacterial control systems and medicines. [ABSTRACT FROM AUTHOR]

The present study conveyed an in-situ synthesis of silver nanoparticles (Ss-AgNPs) using Solanum sisymbriifolium aqueous leaf extract (SsLE) and their biological activities for the first time. The qualitative and quantitative analysis of SsLE imparted significant amounts of reducing entities/ secondary metabolites. A surface plasmon resonance peak at ∼430 nm of UV–visible spectrum evidenced the formation of Ss-AgNPs. The average particle size of the Ss-AgNPs was found to be 29.87 nm through particle size analyzer. Further, FE-SEM, HR-TEM and XRD analysis verified the spherical shape and high degree of crystallinity with face-centred cubic structure of Ss-AgNPs. The EDX, elemental mapping and FTIR spectral studies, confirmed that various phytochemicals/ metabolites of S. sisymbriifolium leaf extract participated in bio-reduction process and capping of Ss-AgNPs, which might be accountable for the antioxidant activities. Moreover, SsLE and Ss-AgNPs were found to be a rich source of antioxidants and exhibited effective DPPH, H 2 O 2 , ṄO scavenging activities along with Ferric ion reducing antioxidant power. The synthesized Ss-AgNPs showed significant antibacterial activity against gram-positive and gram-negative bacteria. In addition to this, Ss-AgNPs supported the degradation of methylene blue (a cationic dye), by performing as a strong photocatalyst under UV and solar irradiations. [Display omitted] • First time report on green-synthesis of AgNPs using S. sisymbriifolium leaf extract. • AgNPs possessed profuse antioxidant property as monitored by four antioxidant assays. • AgNPs showed enhanced antibacterial activity against Gram-negative bacteria. • AgNPs acted as a strong photocatalyst under UV and solar irradiation by degrading MB dye. [ABSTRACT FROM AUTHOR]

The effective control of pathogenic bacteria is crucial in the restoration of periodontal tissue affected by periodontitis. Guided tissue regeneration (GTR) membranes are commonly used to aid in the repair of periodontal defects. Therefore, there is a clear advantage in developing antibacterial periodontal membranes that can effectively eliminate infections and promote tissue regeneration. This study aimed to create a collagen membrane with optimal content of silver nanoparticles (AgNPs) for effective antibacterial properties and minimal toxicity to mammalian cells. Ascorbic acid-reduced AgNPs were incorporated into collagen at the ratio of 0.5%, 1%, 2%, and 3% (based on total dry weight). Collagen/AgNPs hydrogels were compressed and freeze-dried to form membranes and then were characterized. Antibacterial activity was tested against Fusobacterium nucleatum and Enterococcus faecalis, and membrane cytocompatibility was accomplished on human gingival fibroblasts. Membranes with 2% and 3% AgNPs exhibited significant antibacterial activity, while 1% showed minimal activity and 0.5% and 0% showed none. HGF cells on the 3% AgNPs membrane had poor viability, proliferation, and adhesion, but 0%, 0.5%, 1%, and 2% AgNPs membranes showed desirable cellular behavior. In conclusion, the collagen membrane with 2% AgNPs demonstrated both antibacterial capacity and excellent cytocompatibility, making it a promising choice for periodontal treatments, especially in GTR approaches. [ABSTRACT FROM AUTHOR]

Indeed, considerable efforts have been made in the domain of silver nanoparticles, including the construction and wide‐ranging applications. This work involves the synthesis and characterization of salophen anchored silver nanoparticles (AgNPs), and its utilization for selective detection of Fe2+ and Cu2+ ions in DMSO. These AgNPs were synthesized by the reduction of Ag+ ions with salophen ligand, and were characterized by different techniques which include UV‐visible, fluorescence, FTIR, SEM, EDX, TEM, PXRD, DLS, and zeta potential. The negative zeta potential value of −19.6 mV evidenced the stability of the AgNPs. These AgNPs were found to sense Fe2+ and Cu2+ ions selectively in DMSO solution at various concentrations. Instant color change from olive to brown as well as olive to light olive was observed while detecting Fe2+ and Cu2+ ions by the nanoprobe, respectively. UV‐visible and fluorescence spectroscopic investigations were carried out to establish the sensing ability of the nanoprobe. Additionally, AgNPs revealed promising antibacterial activity selectively against gram‐negative bacteria over gram‐positive bacteria. Thus, our approach opens up a new track to design novel and operative functionalized nanomaterials for real‐life sensing and biomedical applications. [ABSTRACT FROM AUTHOR]

Biosynthesized nanoparticles are gaining popularity due to their unique biological applications and biologically active secondary metabolites from plants that contribute to green synthesis. In this study, silver nanoparticles were prepared easily, consistently, affordably, and sustainably using Olea paniculata aqueous leaf extract, which has antibacterial and antioxidant effects. Several techniques were used to characterize the biosynthesized Olea paniculata silver nanoparticles, including UV–Vis spectrophotometer, Scanning electron microscopy (SEM), Fourier transform infrared (FTIR), X-ray diffraction (XRD), and energy-dispersive X-ray analysis (EDAX). FTIR assessed the functional groups that were capping and reducing the biosynthesized AgNPs. The antioxidant activity of the biosynthesized nanoparticles was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH). Both Gram-positive (B. subtilis) and Gram-negative (E. coli, K. pneumoniae) bacteria were used in the testing to determine their antibacterial activity. The biosynthesized nanoparticles demonstrated dose-dependent inhibitory effects with a significant zone of inhibition; a microbe is believed to be more susceptible to an antibiotic if its zone of inhibition is larger. The zone becomes more resistant to the microbes and less sensitive as it gets smaller, and as a result, the zone was more effective against E. coli and K. pneumonia than B. subtilis. E. coli and K. pneumonia were most susceptible and B. subtilis was least susceptible to the low concentration of silver nanoparticles (4 µL). The biosynthesized Olea paniculata AgNPs can be further exploited as a potential candidate for antifungal, antibacterial, and anticancer agents because this study showed that they were associated with good antibacterial activity against specific bacteria when prepared from Olea paniculata leaf extract. [Display omitted] • Fabrication of AgNPs by using leaves extract of Olea paniculata for the very 1st time. • Thorough characterization of AgNPs using particle size analyzer, UV–vis spectrophotometry, SEM, EDX, FTIR, and XRD. • Functional groups and chemical bond analysis to investigate the reduction site and role of Olea paniculata leaves extract. • Evaluation of biological role (antibacterial activity, antioxidant) for medicinal point of view. [ABSTRACT FROM AUTHOR]

Objectives: Silver nanoparticles (AgNPs) are gaining increasing attention in biomedical applications due to their unique properties. Green synthesis methods are environmentally friendly and have demonstrated potential for AgNP production. This study explores the green synthesis of AgNPs using the methanolic extract of Euphorbia milii, a plant known for its medicinal properties. The primary objectives of this research were to synthesize AgNPs using E. milii extract, characterize the nanoparticles (NPs) using various techniques, and evaluate their antibacterial and enzyme inhibitory activities. Methods: E. milii plant extract was utilized for the green synthesis of AgNPs. The characterization of the NPs was performed through ultraviolet-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy (EDX). Antibacterial activity was assessed against Staphylococcus aureus, while enzyme inhibitory assays were conducted against urease, α-glucosidase, carbonic anhydrase II, and xanthine oxidase. Results: The synthesized AgNPs exhibited significant antibacterial effects, with a remarkable 20-mm zone of inhibition against S. aureus, surpassing the efficacy of the plant extract alone. Furthermore, the AgNPs demonstrated remarkable enzyme inhibition, achieving impressive percentages of 77.98% against α-glucosidase and 88.54% against carbonic anhydrase II. Half-maximal inhibitory concentration values for enzyme inhibition were highly promising, including 78.09 ± 1.98 µM for α-glucosidase, 0.22 ± 0.10 µM for carbonic anhydrase II, and 7.11 ± 0.55 µM for xanthine oxidase. Conclusion: In this study, AgNPs were successfully synthesized using E. milii extract and characterized using various techniques. The AgNPs exhibited significant antibacterial and enzyme-inhibitory activities, showcasing their potential for biomedical applications. [ABSTRACT FROM AUTHOR]

Antibacterial resistance among uro-pathogens has become a global issue for bacterial infection treatment. The antibacterial activity of various plant extracts and silver nanoparticles (AgNPs) derived from medicinal plant extract was evaluated against different drug-resistant uro-pathogens isolated from clinical patients by Agar Well Diffusion and Minimum Inhibitory Concentration (MIC) assays. A total of 100 urine samples were collected from patients admitted to the hospital followed by the identification of Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Proteus mirabilis, Enterobacter aerogenes, and Klebsiella pneumonia through colony morphology, gram staining, and biochemical characterization. All isolates were highly resistant to all the tested drugs except Amikacin, Gentamicin, and Imipenem. Organic extracts of clove have potent antibacterial activity against all drug-resistant isolates. Interestingly P. aeruginosa was sensitive to all inorganic extracts. These results revealed that the organic extracts of medicinal plants showed more consistent antimicrobial activity compared to their aqueous fraction. Furthermore, the green synthesis of AgNPs derived from clove extract showed strong activity against all tested pathogens followed by green synthesis of AgNPs derived from garlic, ginger, kalwonji, turmeric, and thymus extract respectively compared to medicinal plant extract. Moreover, MIC results showed that AgNPs derived from medicinal plant extract indicate higher efficiency in inhibiting bacterial growth than the medicinal plant extract. The current finding shows that AgNPs derived from plant extract can be recommended as a good alternative for treating the resistant uro-pathogens strains as compared to synthetic drugs and will be considered an attractive candidate for future biological applications. [ABSTRACT FROM AUTHOR]

The current study explored the use of the ethanolic extract of Enteromorpha intestinalis to determine its capability to synthesize silver nanoparticles. The GC-mass technique was utilized to identify the active compounds in the algal ethanolic extract. The extract's potential in fabricating silver nanoparticles was tested, and their formation was inferred through the color change of the mixture from light green to dark brown. The synthesized nanoparticles were characterized using various techniques, (FTIR) spectroscopy, a scanning electron microscope (SEM), and an energy-dispersive X-ray spectroscopy (EDX). In addition, they were analyzed using X-ray diffraction (XRD). The antibacterial effectiveness was tested through the agar well diffusion method. The GC-mass results showed that the ethanolic extract contained several active compounds, including nhexadecanoic acid (37.40%), neophytadiene (11.08%), 9,12,15-octadecatrienoic acid, (Z, Z, Z)-(17.32%), and oleic acid (10.28%). A peak at 435nm in the UV-vis absorption spectrum confirmed the formation of silver nanoparticles. The XRD technique determined the crystalline nature of the silver nanoparticles, and SEM results showed that they had spherical shapes with sizes ranging between 47-78nm. EDX analysis revealed that the synthesized silver nanoparticles comprised silver, carbon, oxygen, and chlorine. The efficacy of the synthesized silver nanoparticles was tested against four types of pathogenic bacteria, namely E. coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus. The results demonstrated that the silver nanoparticles had a significant inhibitory capability against these pathogens. [ABSTRACT FROM AUTHOR]

This research work explores the green synthesis of silver nanoparticles using Quassia indica(QI-Ag NPs), a natural plant extract, as a stabilizing and reducing agent. The synthesized QI-Ag NPs were characterized using various analytical techniques, including UV-Visible spectroscopy, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), Transmission Electron Microscopy (HR-TEM) and Selected Area Electron Diffraction (SAED). The UV-Visible analysis revealed a characteristic peak at 430 nm, indicating the successful formation of AgNPs. XRD analysis unveiled the crystalline nature of the nanoparticles, with four distinctive peaks corresponding to the silver crystallographic planes. SEM and EDX provided insights into the morphology and chemical composition of the QI-AgNPs. Moreover, TEM and SAED elucidated the structural attributes and crystallinity of the nanoparticles. The Ag NPs exhibited a spherical structure and crystalline nature, as supported by both SAED and XRD findings. The zeta potential of QI-Ag NPs exhibited a value of −24.2 mV. The synthesized QI-Ag NPs were evaluated for their photocatalytic potential, demonstrating a remarkable 97% degradation of Crystal Violet dye. Furthermore, comprehensive studies encompassing antioxidant, antimicrobial and cytotoxicity assessments were conducted, showcasing the multifaceted applications of these nanoparticles. This research underscores the promising potential of Q. indica-mediated silver nanoparticles as environmentally benign and versatile nanomaterials. [ABSTRACT FROM AUTHOR]

Inspired by mussel chemistry, we presented a facile and eco‐friendly method to synthesize silver nanoparticles (AgNPs) using dopamine as a reductant and stabilizer. The synthesized AgNPs as an antibacterial agent and photothermal filler were further introduced to random copolymers of methyl methacrylate and butyl acrylate (MMA‐co‐BA) via latex mixing. The morphology and structure of the formed AgNPs were confirmed by transmission electron microscopy (TEM), UV–Vis spectrum, and x‐ray powder diffraction (XRD). The results showed that the synthesized AgNPs were spherical in the size of 5–30 nm with the characteristic crystalline structure of AgNPs. Mechanical properties of MMA‐co‐BA were significantly enhanced by the introduction of AgNPs. The MMA‐co‐BA/Ag nanocomposite films showed antibacterial activity against E. coli and S. aureus. Moreover, the scratches on the MMA‐co‐BA/Ag nanocomposite film can be healed under infrared light irradiation, which indicated that AgNPs enhanced the self‐healing ability of the MMA‐co‐BA. This work offers a viable avenue for developing antibacterial activity and self‐healing multifunctional coatings. Highlights: Silver nanoparticles modified by dopamine are introduced to acrylic copolymer.Acrylic copolymer/Ag nanocomposites exhibit antibacterial activity.Acrylic copolymer/Ag nanocomposites have photothermal performance.Acrylic copolymer/Ag nanocomposites have self‐healing ability. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (Ag-NPs) have a unique mode of action as antibacterial agents in addition to their anticancer and antioxidant properties. In this study, microbial nanotechnology is employed to synthesize Ag-NPs using the cell filtrate of Streptomyces enissocaesilis BS1. The synthesized Ag-NPs are confirmed by ultraviolet-visible (UV-Vis), Fourier transform infrared (FT-IR), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Also, the effects of different factors on Ag-NPs synthesis were evaluated to set the optimum synthesis conditions. Also, the antibacterial, antibiofilm, and anticancer activity of Ag-NPs was assessed. The X-ray diffraction (XRD) analysis confirmed the crystalline nature of the sample and validated that the crystal structure under consideration is a face-centered cubic (FCC) pattern. The TEM examination displayed the spherical particles of the Ag-NPs and their average size, which is 32.2 nm. Fourier transform infrared spectroscopy (FTIR) revealed significant changes in functionality after silver nanoparticle dispersion, which could be attributed to the potency of the cell filtrate of Streptomyces enissocaesilis BS1 to act as both a reducing agent and a capping agent. The bioactivity tests showed that our synthesized Ag-NPs exhibited remarkable antibacterial activity against different pathogenic strains. Also, when the preformed biofilms of Pseudomonas aeruginosa ATCC 9027, Salmonella typhi ATCC 12023, Escherichia coli ATCC 8739, and Staphylococcus aureus ATCC 6598 were exposed to Ag NPs 50 mg/ml for 24 hours, the biofilm biomass was reduced by 10.7, 34.6, 34.75, and 39.08%, respectively. Furthermore, the Ag-NPs showed in vitro cancer-specific sensitivity against human breast cancer MCF-7 cell lines and colon cancer cell line Caco-2, and the IC50 was 0.160 mg/mL and 0.156 mg/mL, respectively. The results of this study prove the ease and efficiency of the synthesis of Ag-NPs using actinomycetes and demonstrate the significant potential of these Ag-NPs as anticancer and antibacterial agents. [ABSTRACT FROM AUTHOR]

Antimicrobial natural polymer film with silver nanoparticles (AgNPs) biosynthesized using aqueous plant root extracts as reducing capping agents and for film formatting show extensive applicability for pathogenic microorganism problems. The formation of AgNPs was confirmed by transmission electron microscopy (TEM) and scanning electron microscopy–energy-dispersive spectroscopy (SEM–EDS) techniques. The antimicrobial activity of biofilm with green AgNPs was analysed by inhibiting the growth of Gram-negative and Gram-positive bacteria culture using the Kirby–Bauer disk diffusion susceptibility test. Total phenolic content and antioxidant activity were slightly higher in aqueous extracts of Sym. Radix than in Sym. Radix/AgNPs. The antimicrobial effect of polymer film/AgNPs against selected test bacteria cultures was substantially more robust than with pure film. Pictures of AgNPs obtained by TEM revealed the presence of spherical-shaped nano-objects with an average size 27.45 nm. SEM–EDS studies confirmed the uniform distribution of metal nanoparticles throughout the biopolymeric matrix. Morphological studies of the surface showed that the obtained surface of the films was even, without holes or other relief irregularities. These apparent Symphyti radix polymer film/AgNPs' biological functions could provide a platform for fighting pathogenic bacteria in the era of multi-drug resistance. [ABSTRACT FROM AUTHOR]

Modern technology's development is also towards using microorganisms as micro-factories of biomaterials with unique properties and combining the original properties of biosilica extracted from diatoms (microalgae) together with immobilised silver and cerium in nanoparticle forms allowed to obtain a modern composite material with antibacterial activity. The synthesised composites containing heteroepitaxially growing Ag/AgCl/CeO2 complex nanoparticles were studied using different types of instrumental analysis. SEM-EDX and XRD analysis allowed the qualitative and quantitative determination of the elements present and their forms in the composites. TEM permitted analysis of information about the created nanoparticles shape, size and structure specificity. The possible mechanism of nanoparticle formation was suggested. Antibacterial properties of synthesised composites were characterised using a minimum inhibitory concentration test on six selected bacterial strains. Diatomaceous biosilica containing heteroepitaxially growing silver chloride, metallic silver, and cerium (IV) oxide nanoparticles have been prepared for the first time. The proposed method for synthesising composites did not use toxic reagents, making it environmentally friendly. [ABSTRACT FROM AUTHOR]

The evolution and rapid spread of multidrug-resistant (MDR) bacterial pathogens have become a major concern for human health and demand the development of alternative antimicrobial agents to combat this emergent threat. Conventional intracellular methods for producing metal nanoparticles (NPs) using whole-cell microorganisms have limitations, including binding of NPs to cellular components, potential product loss, and environmental contamination. In contrast, this study introduces a green, extracellular, and sustainable methodology for the bio-materialization of silver NPs (AgNPs) using renewable resource cell-free yeast extract. These extracts serve as a sustainable, biogenic route for both reducing the metal precursor and stabilizing the surface of AgNPs. This method offers several advantages such as cost-effectiveness, environment-friendliness, ease of synthesis, and scalability. HR-TEM imaging of the biosynthesized AgNPs revealed an isotropic growth route, resulting in an average size of about ~ 18 nm and shapes ranging from spherical to oval. Further characterization by FTIR and XPS results revealed various functional groups, including carboxyl, hydroxyl, and amide contribute to enhanced colloidal stability. AgNPs exhibited potent antibacterial activity against tested MDR strains, showing particularly high efficacy against Gram-negative bacteria. These findings suggest their potential role in developing alternative treatments to address the growing threat of antimicrobial resistance. Additionally, seed priming experiments demonstrated that pre-sowing treatment with AgNPs improves both the germination rate and survival of Sorghum jowar and Zea mays seedlings. Key points: •Yeast extract enables efficient, cost-effective, and eco-friendly AgNP synthesis. •Biosynthesized AgNPs showed strong antibacterial activity against MDR bacteria. •AgNPs boost seed germination and protect against seed-borne diseases. [ABSTRACT FROM AUTHOR]

Bacterial infections pose a significant threat to human health and safety, necessitating the urgent resolution of the problem through the development and implementation of highly effective antibacterial agents. However, the emergence of multidrug-resistant bacteria has diminished the satisfactory effectiveness of antibacterial treatments. To overcome this obstacle, we developed effective antibacterial agents by chemical reduction for inhibiting bacterial proliferation and inducing membrane damage. Specifically, four different types of chitosan/Ag nanoparticle (CS-AgNPs-i) (i-1, 2, 3, 4) complexes were synthesized by varying the quantity of chitosan added during the synthesis process. We found that the amount of CS does not affect the morphology and size of CS-AgNPs-i, which remained at approximately 20 nm and all CS-AgNPs were mostly spherical. The zeta potential measurements indicated that the surface of CS-AgNPs carries a positive charge. Notably, elevating the chitosan concentration led to a more pronounced antibacterial impact, particularly evident in its interaction with the peptidoglycan layer on the bacterial surface. Our experimental results undeniably establish the potent antibacterial efficacy of CS-AgNPs against both Escherichia coli and Staphylococcus aureus. Employing live/dead bacterial staining, we reveal the marked capability of CS-AgNPs to effectively hinder bacterial proliferation. Furthermore, our experimental investigations revealed that CS-AgNPs possess broad-spectrum antimicrobial activity. The results of in vitro cytotoxicity experiments substantiated the high biocompatibility of CS-AgNPs with elevated chitosan loading. The study provides valuable insights into the development of nano-antibacterial agents that exhibit significant potential as a substitute to replace traditional antibiotics for medical applications. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to address a comprehensive and integrated investigations pertaining to the preparation of AgNPs with well-defined nano-sized scale using the aforementioned poly (meth acrylic acid [MAA])–chitosan graft copolymer, which is cheap, nontoxic, biodegradable and biocompatible agent as a substitute for the traditionally used toxic reducing agents. Design/methodology/approach: AgNPs are prepared under a range of conditions, containing silver nitrate and poly (MAA)–chitosan graft copolymer concentrations, time, temperature and pH of the preparation medium. To classify AgNPs obtained under the various conditions, ultraviolet–visible spectroscopy spectra and transmission electron microscopy images are used for characterization of AgNPs instrumentally in addition to the visual color change throughout the work. The work was further extended to study the application of the so prepared AgNPs on cotton fabric to see their suitability as antibacterial agent as well as their durability after certain washing cycles. Findings: According to the current investigation, the optimal conditions for AgNPs formation of nearly 3–15 nm in size are 5 g/l, poly (MAA)–chitosan graft copolymer and 300 ppm AgNO3 in addition to carrying out the reaction at 60°C for 30 min at pH 12. Besides, the application of the so prepared AgNPs on cotton fabric displayed a substantial reduction in antibacterial efficiency against gram-positive and gram-negative bacteria estimated even after 10 washing cycles in comparison with untreated one. Originality/value: To the best of the authors' information, no comprehensive study of the synthesis of AgNPs using poly (MAA)–chitosan graft copolymer with a graft yield of 48% has been identified in the literature. [ABSTRACT FROM AUTHOR]

The green synthesis of silver nanoparticles (AgNPs) using the cell-free supernatant of a Haematococcus pluvialis culture (CFS) was implemented in the current study, under illumination conditions. The reduction of Ag+ to AgNPs by the CFS could be described by a pseudo-first-order kinetic equation at the temperature range tested. A high reaction rate during synthesis and stable AgNPs were obtained at 45 °C, while an alkaline pH (pH = 11.0) and a AgNO3 aqueous solution to CFS ratio of 90:10 (v/v) proved to be the most effective conditions in AgNPs synthesis. A metal precursor (AgNO3) at the concentration range tested (1–5 mM) was the limited reactant in the synthesis process. The synthesis of AgNPs was accomplished under static and agitated conditions. Continuous stirring enhanced the rate of reaction but induced aggregation at prolonged incubation times. Zeta potential and polydispersity index measurements indicated stable AgNPs and the majority of AgNPs formation occurred in the monodisperse phase. The X-ray diffraction (XRD) pattern revealed the face-centered cubic structure of the formed AgNPs, while TEM analysis revealed that the AgNPs were of a quasi-spherical shape with a size from 30 to 50 nm. The long-term stability of the AgNPs could be achieved in darkness and at 4 °C. In addition, the synthesized nanoparticles showed antibacterial activity against Escherichia coli. [ABSTRACT FROM AUTHOR]

The evolution and rapid spread of multidrug-resistant (MDR) bacterial pathogens have become a major concern for human health and demand the development of alternative antimicrobial agents to combat this emergent threat. Conventional intracellular methods for producing metal nanoparticles (NPs) using whole-cell microorganisms have limitations, including binding of NPs to cellular components, potential product loss, and environmental contamination. In contrast, this study introduces a green, extracellular, and sustainable methodology for the bio-materialization of silver NPs (AgNPs) using renewable resource cell-free yeast extract. These extracts serve as a sustainable, biogenic route for both reducing the metal precursor and stabilizing the surface of AgNPs. This method offers several advantages such as cost-effectiveness, environment-friendliness, ease of synthesis, and scalability. HR-TEM imaging of the biosynthesized AgNPs revealed an isotropic growth route, resulting in an average size of about ~ 18 nm and shapes ranging from spherical to oval. Further characterization by FTIR and XPS results revealed various functional groups, including carboxyl, hydroxyl, and amide contribute to enhanced colloidal stability. AgNPs exhibited potent antibacterial activity against tested MDR strains, showing particularly high efficacy against Gram-negative bacteria. These findings suggest their potential role in developing alternative treatments to address the growing threat of antimicrobial resistance. Additionally, seed priming experiments demonstrated that pre-sowing treatment with AgNPs improves both the germination rate and survival of Sorghum jowar and Zea mays seedlings. Key points: •Yeast extract enables efficient, cost-effective, and eco-friendly AgNP synthesis. •Biosynthesized AgNPs showed strong antibacterial activity against MDR bacteria. •AgNPs boost seed germination and protect against seed-borne diseases. [ABSTRACT FROM AUTHOR]

Ag NPs were generated by reducing silver ions with sodium borohydride and then loaded into a zirconium-based MOF, PCN-222, resulting in a deep purple powder, PCN-222@AgNPs, which exhibited photocatalytic activity. The material was characterized and found to have Ag NPs uniformly dispersed in the pores of PCN-222, with a content of 6.0306%. PCN-222@AgNPs had rod-shaped structures of micrometer sizes with irregular spherical Ag NPs on their surfaces, as revealed by scanning electron microscopy and transmission electron microscopy. In experiments on Ag NPs release and reactive oxygen species (ROS) detection, PCN-222@AgNPs effectively released Ag NPs into an aqueous solution and promote ROS generation. Finally, the antibacterial activities of PCN-222@AgNPs against Escherichia coli and Staphylococcus aureus were assessed by in vitro experiments. Results indicated that PCN-222@AgNPs had lower minimum bactericidal concentration (MBC) compared to PCN-222 in both light and dark environments. The MBC further decreased under light conditions due to the enhanced photocatalytic performance of the composite material and the promotion of Ag NPs release by ROS. These findings demonstrate that PCN-222@AgNPs have synergistic antibacterial effects under visible light irradiation. [ABSTRACT FROM AUTHOR]

Green synthesis of silver nanoparticles (AgNPs) has attracted substantial interest and achievement due to their environmental friendliness, ease of manipulation, and potential for large-scale production. By using aqueous Camellia sinensis leaf extract, suspensions of AgNPs, which possess photocatalytic and biological activity, were successfully synthesized in this study. The reduction of silver ions to AgNPs was visually inspected via the colour of the reaction mixture, which was altered from pale yellow to reddish brown. The methods of characterization of the as-synthesized AgNPs were performed using Ultraviolet-Visible spectroscopy (UV-Vis), dynamic light scattering technique (DLS), and X-ray diffraction analysis (XRD). The surface plasmon resonance bands of AgNPs at 420-430 nm in UV-Vis spectra indicated the presence of silver particles at the nanoscale. The size of AgNPs was determined by DLS, ranging from 25 nm to 40 nm. XRD analysis showed that AgNPs were highly pure and crystalline. The antibacterial activity of AgNPs against Gram-positive and Gram-negative bacterial strains, including Staphylococcus aureus and Escherichia coli, respectively, was demonstrated by the disc diffusion method. The examination of the photocatalytic activity of AgNPs was conducted through methylene blue (MB) degrading experiments, and the MB degrading performance was approximately 95% within 72 h under sunlight. [ABSTRACT FROM AUTHOR]

Uropathogenic Escherichia coli (UPEC) is prevalent in urinary tract infections (UTIs). UPEC's biofilm production enables it to invade and persist in the uroepithelium, leading to recurrent UTIs. The biofilm formation is associated with antibiotic resistance. To overcome this resistance, non-conventional compounds must be developed as an alternative to conventional antibiotics. Silver nanoparticles (AgNPs) are significant due to their antibacterial activity against diverse organisms. This study was done to investigate the antibacterial and anti-biofilm effects of AgNPs on UPEC. AgNPs were biosynthesized using Pseudomonas aeruginosa ATCC 27853. AgNPs were characterized using visual inspection and scanning electron microscopy. The Agar well diffusion method was employed to assess the antibacterial activity of AgNPs against UPEC isolates. The study utilized the tissue culture plate method to investigate both the biofilm and anti-biofilm properties of AgNPs. Following incubation, Ps.aeruginosa and silver nitrate (AgNO3) mixture exhibited a colour change from pale yellow to dark brown. The mean size of spherical AgNPs observed under a scanning electron microscope was 24.187 ± 8.019 nm. 130 UPECs were obtained. AgNPs exhibited antibacterial activity at a concentration of 20 µg/ml against all tested UPEC strains. Among UPEC strains that produced biofilms, a significant inhibition of 99.89 ± 0.45% was observed at a higher concentration of 512 µg/ml of AgNPs. Ps.aeruginosa produces nitrate reductase enzyme that can potentially convert AgNO3 to AgNPs. The biosynthesized AgNPs exhibit antibacterial and anti-biofilm activity against all tested UPEC strains. [ABSTRACT FROM AUTHOR]

The investigation of using medicinal plants for the production and application of silver nanoparticles (AgNPs) has attracted growing research interest. In this study, AgNPs are synthesized from the stem barks of the Pyrus pashia medicinal plant using a biosynthetic strategy. The reaction conditions were optimized under ambient conditions, including concentration, temperature, time, and pH, and various techniques were employed, such as UVvisible, FTIR, XRD, FESEM, and TEM, to characterize the synthesized AgNPs. The AgNPs produced through this biosynthesis method were found to be spherical and polydispersed, with an average size of 23.92 ± 7.04 nm. The synthesized AgNPs demonstrated an enhanced DPPH free radical scavenging capacity compared to the aqueous extract, with IC50 values of 10.67 ± 0.05 µg/mL and 13.66 ± 0.35 µg/mL, respectively. In the agar well diffusion method, the synthesized AgNPs showed higher antibacterial activity than that of the extract against Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 25923), Enterococcus faecalis (ATCC 29212), Salmonella typhi (ATCC 14028), and Shigella sonnei (ATCC 25931). Based on these findings, the study suggests that green synthesized AgNPs from P. pashia could be used for biomedical applications. [ABSTRACT FROM AUTHOR]

Uncontrollable bleeding continues to stand as the primary cause of fatalities globally following surgical procedures, traumatic incidents, disasters, and combat scenarios. The swift and efficient management of bleeding through the application of hemostatic agents has the potential to significantly reduce associated mortality rates. One significant drawback of currently available hemostatic products is their susceptibility to bacterial infections at the bleeding site. As this is a prevalent issue that can potentially delay or compromise the healing process, there is an urgent demand for hemostatic agents with antibacterial properties to enhance survival rates. To mitigate the risk of infection at the site of a lesion, we propose an alternative solution in the form of a chitosan-based sponge and antimicrobial agents such as silver nanoparticles (AgNPs) and lavender essential oil (LEO). The aim of this work is to provide a new type of hemostatic sponge with an antibacterial barrier against a wide range of Gram-positive and Gram-negative microorganisms: Staphylococcus epidermidis 2018 and Enterococcus faecalis VRE 2566 (Gram-positive strains) and Klebsiella pneumoniae ATCC 10031 and Escherichia coli ATCC 35218 (Gram-negative strains). [ABSTRACT FROM AUTHOR]

The era of increasing bacterial antibiotic resistance requires new approaches to fight infections. With this purpose, silver-based nanomaterials are a reality in some fields and promise new developments. We report the green synthesis of silver nanoparticles (AgNPs) using culture broths from a microalga. Broths from two media, with different compositions and pHs and sampled at two growth phases, produced eight AgNP types. Nanoparticles harvested after several synthesis periods showed differences in antibacterial activity and stability. Moreover, an evaluation of the broths for several consecutive syntheses did not find relevant kinetics or activity differences until the third round. Physicochemical characteristics of the AgNPs (core and hydrodynamic sizes, Z-potential, crystallinity, and corona composition) were determined, observing differences depending on the broths used. AgNPs showed good antibacterial activity at concentrations producing no or low cytotoxicity on cultured eukaryotic cells. All the AgNPs had high levels of synergy against Escherichia coli and Staphylococcus aureus with the classic antibiotics streptomycin and kanamycin, but with ampicillin only against S. aureus and tetracycline against E. coli. Differences in the synergy levels were also dependent on the types of AgNPs. We also found that, for some AgNPs, the killing of bacteria started before the massive accumulation of ROS. [ABSTRACT FROM AUTHOR]

The prevalence of numerous infectious diseases has emerged as a grave concern within the realm of healthcare. Currently, the issue of antibiotic resistance is compelling scientists to explore novel treatment approaches. To combat these infectious diseases, various treatment methods have been developed, harnessing cutting-edge disinfecting nanomaterials. Among the range of metallic nanoparticles employed in medicine, silver nanoparticles (AgNPs) stand out as both highly popular and well-suited for the task. They find extensive utility in cancer diagnosis and therapies and as effective antibacterial agents. The interaction between silver and bacterial cells induces significant structural and morphological alterations, ultimately leading to cell demise. In this study, nanoparticles based on silver and bambusuril[6] (BU[6]) were developed for the first time. These NPs can be used for different biomedical purposes. A simple, single-step, and effective synthesis method was employed to produce bambusuril[6]-protected silver chloride nanoparticles (BU[6]-Ag/AgCl NPs) through the complexation of BU[6] with silver nitrate. The NPs were characterized using X-ray phase analysis (XPS), infrared spectroscopy (IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). When the SEM images were examined, it was seen that the synthesized BU[6]-Ag/AgCl NPs were distributed with homogeneous sizes, and the synthesized NPs were mostly spherical and cubic. The EDS spectra of BU[6]-Ag/AgCl NPs demonstrated the presence of Ag, Cl, and all expected elements. BU[6]-Ag/AgCl NPs showed high antibacterial activity against both E. coli and S. aureus bacteria. [ABSTRACT FROM AUTHOR]

One of the most recent areas of interest in current nanotechnologies and nanosciences is the use of biomaterials in the manufacturing of nanoparticles. More and more research is being carried out on environmentally friendly methods to create metal oxide nanoparticles (NP), with the intention of preventing any potential risks associated with harmful substances for a safe and healthy environment. In this study, Copper Oxide (CuO) is synthesized utilizing Opuntia ficus‐indica as the plant extract using a Microwave Combustion Technique (MCM) and its comparison against the Conventional Combustion Method (CCM) are investigated. The synthesized CuO nanoparticles were characterized using X‐ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT‐IR), Scanning Electron Microscopy (SEM), and Energy Dispersive X‐ray Analysis (EDX) analysis. Photoluminescence spectroscopy was undertaken to acquire emission and absorption spectra and determine defects in the structures of all synthesized nanopowder samples. The antibacterial activity of the CuO nanoparticles was evaluated in‐vitro using gram‐negative and gram‐positive bacteria (Bacillus subtilis, Staphylococcus aureus). Enhanced anti‐bactericidal activity was shown against Gram‐negative bacteria compared to Gram‐positive bacteria. Through these findings, the use of CuO using Opuntia ficus indica extracts is hereby shown to be a cost‐effective and environmentally friendly alternative and that can be used in a variety of applications. [ABSTRACT FROM AUTHOR]

Objective: The purpose in the study was to evaluate the effect of biogenic silver nanoparticles (Ag NPs) synthesized by the green synthesis method on dentin bond strength in three different universal adhesives and investigate their antibiofilm activity against Streptococcus mutans (S. mutans). Materials and methods: Three different universal adhesives (single bond universal, all-bond universal, and clearfil universal) were used in this study. Ag NPs were synthesized using rose hip (Rosa canina) extract as a reducing and stabilizing agent and they were characterized with STEM, UV–vis spectrophotometer, DLS, and zeta potential. Ag NPs were added to the adhesive resins at a rate of 0.05% (w/w), and their homogeneous distribution in the adhesive was determined using EDX spectrometry. Samples in all groups were tested at baseline-after 5000 and 10,000 thermal cycles. Adhesive composite discs were used for the live/dead analysis of S. mutans, MTT metabolic activity test, lactic acid production, and determination of colony-forming unit (CFU) values (n = 3). Ninety extracted caries-free human third molars were used to determine microtensile bond strength (μTBS) (n = 10). After the universal adhesive was applied to the dentin surface, composite resin (Z550 XT, 3 M ESPE, USA) was placed and sections were taken to form a composite-dentin stick of 1 mm × 1 mm wideness and 8-mm length. The sticks were broken at a rate of 1 mm/min under uniaxial tension in a universal testing machine, and the failure modes were determined by SEM. One-way analysis of variance (ANOVA) for antibacterial tests and two-way analysis of variance for μTBS tests were performed (p < 0.05). Results: All universal adhesive groups containing Ag NPs showed higher antibacterial activity than control groups without Ag NPs (p < 0.05). There was a statistically significant difference in the live/dead assay analysis, MTT metabolic activity test, lactic acid production, and CFU values in the thermal cycled Ag NPs groups (p < 0.05). Antibacterial activity decreased in groups containing Ag NPs subjected to 10,000 thermal cycles. The highest lactic acid production 11.06 (± 0.629) and CFUs 7.61 (± 0.304), live bacteria 31.13 (± 0.466), and S. mutans MTT metabolic activity 0.29 (± 0.376) at AU (All-Bond Universal—Ag NPs) 10,000 thermal cycles group. There was no difference in μTBS values between the initial and 5000 thermal cycle groups, there was a difference between the 10,000 thermal cycle groups. The CU (Clearfil Universal—Ag NPs) group subjected to 10,000 thermal cycles showed lower μTBS 11.1 (± 3.2). Conclusion: In conclusion, universal adhesives containing biogenic Ag NPs showed higher antibacterial activity than the control groups and did not reduce the μTBS. Clinical relevance: Antibacterial universal adhesives can contribute to restoration success in clinical applications by reducing residual bacteria and preventing secondary caries formation. [ABSTRACT FROM AUTHOR]

This study aims to develop and characterize rice starch nanocomposites containing silver nanoparticles (AgNPs) derived from onion peel extract (OPE) as a reducing agent. The scanning electron microscopy (SEM) images reveal the formation of semi‐spherical shaped nanoparticles. Also, the peaks obtain at 3 keV using energy dispersive spectroscopy (EDS) indicates the presence of elemental silver. Active films loaded with AgNPs are subjected to SEM and show that incorporation of AgNPs lead to the development of embedded starch matrix as compared to control sample. The decrease in moisture content and water vapor permeability is quite noticeable by increasing the AgNPs concentration and ranges between (8.58–11.32)% and (6.74–10.90) × 10−9 g−1 s−1 Pa−1, respectively. The results of tensile test suggest that tensile strength is significantly increased after incorporation of nanoparticles in films. The active films possess improved antibacterial activity against food pathogens. Hence, the present investigation suggests economical and advantageous way to formulate nanocomposite films from rice starch that are loaded with AgNPs derived from an agro waste material, i.e., onion peels that are rich in phenolic compounds but are usually discarded by food processors. [ABSTRACT FROM AUTHOR]

Application of nanotechnology for the synthesis of silver nanoparticles using plant extract can be a promising alternative to traditional chemical methods. Products of biological origin have less side effects, thus are safe for human health besides being cost-effective and pollution-free. Keeping in view this, the current work was designed for the environment-friendly production of silver nanoparticles (AgNPs) utilising Isodon coetsa acetone leaf extract. The effect of some important variables including incubation time, pH, AgNO3 concentration, temperature and volume of plant extract were examined for the optimum production of AgNPs. Synthesized nanoparticles were further characterized using atomic force microscopy (AFM), X-ray diffraction spectroscopy (XRD), and UV-visible absorption spectroscopy. In addition, the antibacterial potential of nanoparticles was also determined by agar-well diffusion method. The optimal conditions for synthesis of AgNPs achieved after 24 h of incubation at pH 9.0, 2mM AgNO3, 60°C temperature, and using 10% I. coetsa leaf extract. X-ray diffraction spectroscopy revealed that the size of the strongest peak for AgNPs was 9.5 nm, while atomic force microscopy confirmed their spherical shape with smooth surface without any pinholes or cracks. AgNPs showed excellent antibacterial action against Gram-positive and Gram-negative bacteria. The current study has contributed to the development of a simple and fast bioprocess for the synthesis of AgNPs of the appropriate size and form which also have increased antibacterial activity in comparison to crude extract. Therefore, the process of biogenically synthesised AgNPs from plants is a straightforward, commercially feasible, and environmentally benign approach that can be used in disease control while utilizing their important role as therapeutic agent for treating various ailments caused by pathogenic bacteria. [ABSTRACT FROM AUTHOR]

Objective: The current study's objective is to highlight the value of using plant resources to identify key bioactive molecules and implement green chemistry in research and development to meet market demand. Materials and Methods: The black cumin seeds (Saudi and Syria originated) were utilized to make silver nanoparticles (Ag-NPs), which were subsequently confirmed using a UV spectrophotometer and color analysis of reaction mixtures. The antibacterial activity of Ag-NPs was tested against E. coli, K. pneumoniae, and S. aureus, and antioxidant activity was measured using the DPPH assay. Swiss-ADME, pkCSM, and ProTox-II were also used to assess the pharmacokinetics, oral bioavailability, toxicity, and safety endpoints of molecules. Result: The antibacterial effect of Ag-NPs from Saudi-origin black cumin seeds was observed higher. In comparison to the standard, the Saudi and Syrian Ag-NPs combined displayed synergistic antibacterial effects and were found to be more susceptible to S. aureus. In comparison to the reference, the antioxidant activity of Ag-NPs indicated 60–85% radical scavenging. All molecules passed the Lipinski rule, the filter (Veber, Egan, and Muegge), PAINS, and the Brenk structural alert (zero violations), and the synthetic score was also found to be in the easy limit (1 to 2). The compounds were found to be non-substrate for p-glycoprotein, high GIA% (>90%), non-inhibitor for CYP3A4, CYP2C19, CYP2C9, CYP2D6 (except 5 and 10), Log Po/w (1.71 to 3.26), TPSA 150 2 and MR 155. The compounds likewise had high Caco2 values (log Papp >0.9) with the exception of 4 and 9 (log Papp 0.9), were non-inhibitors of P-gp-I and II and hERG I and II, and showed no AMES toxicity. Except for molecule 11, no organ damage (hepatotoxicity) or endpoint toxicity (mutagenicity, immunotoxicity, carcinogenicity, and cytotoxicity) was identified in ProTox-II. Conclusion: The current study sheds new light on the significance of bioactive molecules found in black cumin seeds, with molecules 3 and 6 identified as potential leads (highest GIA%, no AMES toxicity, oral rat acute and chronic toxicity, lack of renal OCT2 substrate, high total clearance, and lack of organ toxicity) for further research for a variety of medical applications. [ABSTRACT FROM AUTHOR]

The scientific society is exploiting the use of nanoparticles in nano-medicine and biomedical applications. In the field of biomaterial and bio-nanotechnology, silver nanoparticles (AgNPs) are playing an important role due to their potential physical, chemical, and biological properties ranging in activities from antibacterial, antiviral, antifungal, and anticancer treatment. Green synthesis technology is one of the most cost-effective, eco-friendly, and biologically safe methods. Green tea leaf extract can reduce silver to AgNPs and enhance antibacterial activity. In this work, we demonstrate the antibacterial activity effect employing green synthesis of AgNPs with green tea leaf extract. The UV–Vis and FTIR results showed, confirming the formation of AgNPs and the presence of chemical groups enhancing the antibacterial activity of AgNPs. The synthesized AgNPs with green tea leaf extract were crystalline with a quasi-spherical shape with a diameter from 30 to 150 nm. The antibacterial activity of the AgNPs in three different concentrations showed that the 120 mg/ml sample possesses higher antibacterial activity (significantly high killing ability) against E. coli than chemically produced AgNPs. These results confirm a more significant antibacterial effect of the biogenic AgNPs with low cytotoxicity than the AgNPs produced chemically. These findings can be used to treat chronic infections, diseases, and other biomedical applications. [ABSTRACT FROM AUTHOR]

The nanoparticles biosynthesis is disclosing a new route of exploration concerned with nanotechnology. Silver nanoparticles (AgNPs) are integrated in familiar techniques via chemical routs, for having utterly toxic natures. Syzygium aromaticum is an aromatic plant which belongs to the genus Eugenia. Three species of the genus Streptococcus were tested using LB for their ability to produce AgNPs and all of them had a brown appearance that confirmed their involvement in AgNPs production. AgNPs were estimated by utilizing a spectrophotometer. The antimicrobial enterprise (AgNPs) of the three species was tested against several types of dangerous bacteria. To determine the MIC, three separate concentrations (v/v) of 0.5%, 5% and 10% of clove oil with dimethyl sulfoxide (DMSO) were prepared (well diffusion technique). Clove oil extract together with AgNPs biosynthesized from three kinds of Streptococcus, were shown to have antimicrobial effects on unusual clinical microorganisms. [ABSTRACT FROM AUTHOR]

The use of plant extracts to produce metal particles at the nanoscale has attracted intensive research interest due to their cost-effectiveness and eco-friendliness. This study aimed to investigate the synthesis of silver nanoparticles (AgNPs(using aqueous extracts of Silybum marianum L. and Portulaca oleracea L. and to assess their effectiveness as antibacterial and antifungal agents using the agar-well diffusion method. The production of AgNPs was confirmed through spectrophotometry, and their size and shape were measured using Transmission Electron Microscopy (TEM). The role of organic compounds in nanoparticle synthesis was also explored through Fourier Transform Infrared Spectroscopy (FTIR). The FTIR analysis identified the functional groups of organic compounds in S. marianum and P. oleracea extracts that were responsible for reducing Ag ions and capping the resulting AgNPs. The nanoparticles demonstrated potent antimicrobial properties against Escherichia coli, Staphylococcus aureus, Fusarium graminearum, and Alternaria alternata. It was concluded that, in addition to their unique medicinal properties, S. marianum and P. oleracea can be utilized in the production of AgNP for medical and pharmaceutical purposes against Gram-positive and Gram-negative bacteria, as well as fungal infections. In summary, the seed extracts of S. marianum and P. oleracea, which are among the available plant sources, can be used for the highly stable production of AgNPs as a reducing and capping agent. [ABSTRACT FROM AUTHOR]

Silver nanoparticles have special plasmonic and antibacterial characteristics that make them efficient in a variety of commercial medical applications. According to recent research, chemically synthesized silver nanoparticles are harmful even in low concentrations. It was crucial to identify appropriate synthesis methods that may have low costs and be nontoxic to the environment. Zingiber officinale (ginger) extracts used to prepare silver nanoparticles were inexpensive and environmentally friendly, and the best physicochemical characteristics were analyzed. Silver nanoparticles were characterized by using UV-visible spectroscopy, Scanning electron microscopy (SEM), and X-ray diffraction (XRD). The surface Plasmon resonance peak at 425 nm was observed using UV-Visible spectroscopy. Scanning electron microscopy observed that the nanoparticles were spherical and ranged in size from 5 to 35 nm. The XRD pattern values of 2θ: 38.2o, 46.3o, and 64.58o are used to determine the planes (111), (200), and (220). The silver nanoparticle's existence was verified by the face-centered cubic (FCC). Silver nanoparticles were found to have antibacterial efficacy against gram-positive Staphylococcus and gram-negative bacteria such as Pseudomonas aeruginosa, Klebsiella Aerogenes, Salmonella, Staphylococcus and Escherichia coli. The antibacterial activity of silver nanoparticles was observed using the agar well diffusion (AWD) method at three different concentrations (100 μg/ml, 75 μg/ml, and 50 μg/ml). The zone of inhibition measured against the bacterial strains pseudomonas Aeruginosa, Klebsiella aerogenes, Escherichia coli, Salmonella and Staphylococcus which were (18.4±1.25 mm, 16.9±0.74 mm, 14.8±1.25 mm), (16.8±0.96 mm, 14.6±0.76 mm, 14.0±1.15 mm), (19.7±0.76 mm, 18.2±0.66 mm, 15.4±1.15 mm), (16.6±0.67 mm, 14.2±0.23 mm, 12.8±0.78 mm) and (12±0.68 mm, 10±0.20 mm, 08±0.15 mm). These nanoparticles' potent antibacterial properties may enable them to be employed as nanomedicines for a variety of gram-negative bacterial illness treatments. [ABSTRACT FROM AUTHOR]

Bacterial infection caused by medical material is a common problem in the field of medicine. In this work, we aim to develop a novel antimicrobial bioplastic with potential medical value. A novel composite material composed of polyamino acid (PAA) and titanium dioxide/silver nanoparticles (TiO2/Ag NPs) was synthesized by in situ melting polycondensation with different TiO2/Ag loadings. The morphological, antibacterial, mechanical, thermal, and cytotoxicity properties of the PAA/TiO2/Ag composites were investigated. The results showed that uniform nanocomposites with amide bonds were synthesized, and the nanocomposites with 10% TiO2/Ag incorporation exhibited the best thermal and mechanical properties. Cytotoxicity assay showed that the composites significantly promoted the proliferation of MG‐63 cells. The composites showed obvious inhibitory effect on both Escherichia coli and Staphylococcus aureus, and this effect was increased as the TiO2/Ag NPs doping was increased. These PAA/TiO2/Ag composites are suitable for antibacterial and high‐performance biomaterials in the medical field. [ABSTRACT FROM AUTHOR]

Alternative antibacterial options and nanotechnology have gained attention as a solution to the current antibiotic resistance crisis. The use of microorganisms to synthesize nanoparticles is applauded as a sustainable alternative for the production of metal-based nanoparticles. This research screened Bacillus thuringiensis (Bt) isolated from soils collected from different sites (farmland, cattle rangeland and metal recycling dumpsite) for their silver nanoparticles (AgNPs) synthesis potential, characterised the AgNPs and assessed their antibacterial activity against selected drug-resistant bacteria. The Bt index of the sampled sites ranged from 0.1 (farmland) to 0.5 (cattle rangeland). Out of six confirmed Bt isolates; MRS21 and CR23 were selected for their AgNP synthesis potential based on their absorbance of AgNPs at 420 nm. Both isolates produced AgNPs which were anistropic and irregular in shape. The surface plasmon resonance of silver occurred at 434.5 and 440 nm with distinct FT-IR peaks at 3379 and 1643 cm− 1. Apart from the multidrug-resistant E. coli (strain 1), the AgNPs from the two selected isolates exhibited antibacterial activity against E. coli (strain 2), S. aureus and K. pneumoniae. Antibacterial activity of the AgNPs was achieved at 25 µg/mL with MIC of 25–50 µg/mL and MBC of 75–100 µg/mL. Further studies are required to assess the effect of environmental factors on the properties of AgNPs synthesized, their mechanism of antibacterial activity and, synergistic effect of AgNP and antibiotics. [ABSTRACT FROM AUTHOR]

This study investigated the photocatalytic and antibacterial activities of plant-mediated silver nanoparticles (AgNPs) from a medicinal plant extract of Khaya senegalensis (K. senegalensis) and oxygen functionalized carbon nanotubes (oCNTs), respectively. The CNTs were functionalized using acid treatment. The green synthesized AgNPs from K. senegalensis (KS-AgNPs) and oCNTs were characterized by UV--Visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), transmission emission microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The formation of KS-AgNPs was confirmed by the UV--Vis absorption spectra, which showed an absorption band at 427 nm with a color change from yellow to brown. The morphology of KS-AgNPs was spherical in shape, with an average particle size of 9.30 nm. The FTIR analyses revealed distinctive functional groups, such as, hydroxyl (O-H), amines (N-H), and carbonyl (C-O), which were directly involved in the synthesis and stability of AgNPs. The XRD spectra was distinctive with five intense peaks at 2θ angles of 38.12°, 44.28°, 64.43°, 77.48°, and 81.54° while oCNTs gave intense peaks at 2θ angles of 26.43°, 42.36°, 44.46°, 54.51°, 59.98°, and 77.40°. The photocatalytic property of green synthesized KS-AgNPs was determined to be 40.7 % higher than that of oCNTs when applied for treatment of industrial waste water. The ability of green-mediated KS-AgNPs to inhibit against gram-positive and gram-negative bacteria was observed to be that gram (-) bacteria (E. coli) was more susceptible to KS-AgNPs than the gram (+) bacteria (S. aureus), in which case their susceptibility was least in oCNTs for both bacteria, respectively. [ABSTRACT FROM AUTHOR]