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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 the present study, green synthesis of silver nanoparticles (VNE-AgNPs) via Verbascum nudatum extract was carried out for the first time. The synthesized AgNPs were characterized by different spectral methods such as UV–vis, FTIR, XRD, TEM, and EDAX. According to TEM analyses, the average size range of AgNPs was 17–21 nm, and the dominant peaks in the 111°, 200°, 221°, and 311° planes in the XRD pattern indicated the Ag-NPs FCC crystal structure. FTIR data showed that VNE-AgNPs interacted with many reducing, capping, and stabilizing phytochemicals during green synthesis. VNE-AgNPs had higher antibacterial activity against S. aureus and E. coli bacterial strains with a maximum inhibition zone of 21 and 18 mm, respectively, than penicillin 5 IU, used as a positive control in the study. The cytotoxic effect of VNE-AgNPs appeared at a concentration of 50 µg/mL in L929 cells and 5 µg/mL in cancer (A549) cells. When the impact of VNE-AgNPs and C-AgNPs on inflammation was compared, it was found that VNE-AgNPs increased TNF-α levels (333.45 ± 67.20 ng/mg-protein) statistically (p < 0.05) more than TNF-α levels (256.92 ± 27.88 ng/mg-protein) in cells treated with C-AgNPs. VNE-Ag-NPs were found to have a degradation efficiency of 65% against methylene blue (MB) dye within 3 h. [ABSTRACT FROM AUTHOR]

This study investigates Guiera senegalensis J.F. Gmel (Combretaceae), a widely acknowledged herb in Africa for its medicinal properties against various ailments, including fever, diarrhea, diabetes, dysentery, eczema, malaria, cough, tuberculosis, and its potential to enhance milk production in lactating women. The research focuses on utilizing Guiera senegalensis for synthesizing silver nano-particles (GS-AgNPs), due to its abundance in primary and secondary metabolites. The primary aim is to produce GS-AgNPs and assess their antibacterial efficacy. The synthesis of GS-AgNPs involved mixing a silver salt solution with the water leaf-extract. Characterization of the nanoparticles was conducted using Ultraviolet-visible spectroscopy with surface-plasmon-resonance (S-P-R) analysis at 390 nanometers (nm). Fourier transform infrared spectroscopy (F-T-IR) investigated the identity of the phytochemicals responsible for the green reduction of silver ions. X-ray diffraction (X-RD) confirmed the face-centered-cubic crystallinity of the GS-AgNPs with a mean size (33 nm). The antibacterial potential of GS-AgNPs was evaluated against both gram-negative (Escherichia coli and Salmonella typhi) and gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) using the Agar-well method. Results demonstrated the inhibitory effect of GS-AgNPs on microbial growth, with zone-of-inhibition (ZOI) ranging from 4-7 millimeters (mm) to 16-19 mm at concentrations of 10 mg/cm³ and 20 mg/cm³, respectively. In comparison, the aqueous leaf extract exhibited Z-OI between 1.3-6 mm. GS-AgNPs displayed superior antibacterial activity against both Gram-positive and Gramnegative bacteria when compared to the aqueous leaf extract. [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]

A rapid, eco-friendly, and simple method for the synthesis of long-lasting (2 years) silver nanoparticles (AgNPs) is reported using aqueous leaf and petal extracts of Tagetes erecta L. The particles were characterized using UV-Visible spectrophotometry and the analytical and crystallographic techniques of transmission electron microscopy (TEM). The longevity of the AgNPs was studied using UV-Vis and high-resolution TEM. The antibacterial activity of the particles against Erwinia amylovora was evaluated using the Kirby–Bauer disk diffusion method. The results were analyzed using ANOVA and Tukey's test (p ≤ 0.05). Both the leaf and petal extracts produced AgNPs, but the leaf extract (1 mL) was long-lasting and quasi-spherical (17.64 ± 8.87 nm), with an absorbance of UV-Vis λmax 433 and a crystalline structure (fcc, 111). Phenols, flavonoids, tannins, and terpenoids which are associated with -OH, C=O, and C=C were identified in the extracts and could act as reducing and stabilizing agents. The best antibacterial activity was obtained with a nanoparticle concentration of 50 mg AgNPs L−1. The main contribution of the present research is to present a sustainable method for producing nanoparticles which are stable for 2 years and with antibacterial activity against E. amylovora, one of most threatening pathogens to pear and apple productions. [ABSTRACT FROM AUTHOR]

Silver nanoparticles have shown inhibitory capabilities and its use in battling viral infections are strengthened by its potent antibacterial activity. Notably, since it directly affects antiviral efficacy, the proper choice of synthesis process for making silver nanoparticles is a vital element to be taken into consideration. The synthesis of silver nanoparticles for the treatment of viral and bacterial infections involves creating silver particles at the nanoscale with unique antimicrobial properties. Various methods exist for synthesizing silver nanoparticles, including chemical reduction, green synthesis, and physical methods. Chemical reduction involves using reducing agents to convert silver ions into silver nanoparticles. Green synthesis employs reducing agents in an environmentally friendly manner. Physical methods rely on techniques such as laser ablation or thermal evaporation to produce silver nanoparticles. In order to provide technological guidance for choosing antiviral silver nanoparticle manufacturing methods, this paper introduces and explores alternative synthesis methods for creating silver nanoparticles. [ABSTRACT FROM AUTHOR]

The synthesis of Cyanobacteria‐mediated nanoparticles has attracted great attention due to its ecofriendly, cost‐effective and biocompatible properties. Silver nanoparticles (AgNPs) are used in different areas such as medicine, household products, disinfectants or food storage. The present study aimed the biosynthesis of AgNPs from Cyanobacterial Chroococcus sp. and their antimicrobial activities on some important pathogen bacterial species. According to the obtained data, optimal conditions for synthesis of AgNPs were extract rate 3 : 1 v/v (cell extract/AgNO3), silver salt concentration 10 mM, pH 7, temperature 60 °C and time 30 minutes. The surface plasmon resonance peak of AgNPs was observed at 420–430 nm, and AgNPs were well‐dispersed spherical with an average size of 11–13 nm in diameter by TEM. SEM‐EDX analysis revealed a strong signal of silver. With FTIR analyzes, shift in the absorption bands after the AgNPs formation was confirmed. X‐ray diffraction analysis exhibited that the AgNPs were cubic crystalline shape. Zeta potential of AgNPs showed ‐ 20 mV. The AgNPs strong showed antibacterial activity on an opportunistic bacterial pathogens of Micococcus luteus, Bacillus subtilis and Pseudomonas aeroginosa. The effective and rapid synthesis of Chroococcus‐mediated AgNPs and their strong antimicrobial effects can create an important potential for their use in biomedical and environmental applications. [ABSTRACT FROM AUTHOR]

Green silver nanoparticles (AgNPs) possess tremendous promise for diverse applications due to their versatile characteristics. Coriander and other plant extracts have become popular for greenly synthesizing AgNPs as an economical, biocompatible, cost-effective, and environmentally beneficial alternative to chemical processes. In this study, we synthesized AgNPs from coriander leaves and evaluated their antibacterial, anti-inflammatory, antioxidant, and wound-healing acceleration properties in comparison to chemically synthesized AgNPs. The zeta potentials of AgNPs extracted from green and chemical processes were −32.4 mV and −23.4 mV, respectively. TEM images showed a cuboidal shape of green and chemical AgNPs with a diameter of approximately 100 nm. The FTIR spectra of green AgNPs showed an extreme absorption peak at 3401 cm−1, which signifies O-H stretching vibrations, typically linked to hydroxyl groups. In vitro results elaborated that AgNPs from coriander exerted a stronger effect on anti-Klebsiella pneumoniae (KP) through interrupting cell integrity, generating ROS, depleting ATP, and exhibiting significant antioxidant activity, compared with AgNPs synthesized chemically. In vivo experiments showed that AgNPs from coriander, as opposed to chemically manufactured AgNPs, greatly accelerated the healing of wounds contaminated with Klebsiella pneumoniae bacteria by effectively eliminating the bacteria on the wounds and stimulating skin regeneration and the deposition of dense collagen. In vivo assays further demonstrated that green AgNPs effectively enhanced Klebsiella pneumoniae-infected wound healing by extenuating local inflammatory responses and up-regulating VEGF and CD31 expression. In conclusion, green AgNPs significantly alleviated the inflammation without significantly harming the organism. [ABSTRACT FROM AUTHOR]

Natural products derived from medicinal plants offer convenience and therapeutic potential and have inspired the development of antimicrobial agents. Thus, it is worth exploring the combination of nanotechnology and natural products. In this study, silver nanoparticles (AgNPs) were synthesized from the leaf extract of Ginkgo biloba (Gb), having abundant flavonoid compounds. The reaction conditions and the colloidal stability were assessed using ultraviolet–visible spectroscopy. X-ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy (FTIR) were used to characterize the AgNPs. AgNPs exhibited a spherical morphology, uniform dispersion, and diameter ranging from ~8 to 9 nm. The FTIR data indicated that phytoconstituents, such as polyphenols, flavonoids, and terpenoids, could potentially serve as reducing and capping agents. The antibacterial activity of the synthesized AgNPs was assessed using broth dilution and agar well diffusion assays. The results demonstrate antibacterial effects against both Gram-positive and Gram-negative strains at low AgNP concentrations. The cytotoxicity of AgNPs was examined in vitro using the CCK-8 method, which showed that low concentrations of AgNPs are noncytotoxic to normal cells and promote cell growth. In conclusion, an environmentally friendly approach for synthesizing AgNPs from Gb leaves yielded antibacterial AgNPs with minimal toxicity, holding promise for future applications in the field of biomedicine. [ABSTRACT FROM AUTHOR]

Solanum elaeagnifolium is a medicinal plant in the Solanaceae family and the leaves extract have traditionally been used to treat several diseases, including skin infections, respiratory problems, and digestive disorders. The purpose of the study was to formulate silver nanoparticles (AgNPs) from the leaves extract of Solanum elaeagnifolium using the green synthesis method and to evaluate the formulated nanoparticles using scanning electron microscope (SEM) and X-ray diffraction (XRD). The powdered leaves were analyzed for macroscopic, microscopic, and physicochemical characteristics before being extracted using a Soxhlet apparatus. The antioxidant effect was analyzed using 2,2-diphenyl-1-picryl hydrazyl (DPPH). The disk diffusion method was used for assessing the antibacterial activity. Microscopic examinations confirmed the existence of stellate trichomes. Phytochemical screening, confirmed the presence of flavonoids, alkaloids, tannins, saponins, triterpenoids, steroids, and cardiac glycosides. SEM revealed a porous, spherical and crystalline structure with particle sizes of 70-95 nm. The DPPH assay revealed IC50 values of 3.40, 2.30 and 1.40 mg/mL for the methanolic extract, silver nanoparticles and ascorbic acid respectively. The results of the antioxidant studies revealed that the formulated silver nanoparticles had higher antioxidant activity than the leaves extract at all concentrations. The leaves extract and silver nanoparticles demonstrated significant antibacterial activity against all the bacteria used in the study with zones of inhibition ranging from 2.9-4.8 mm and 5.7-9.2 mm respectively. The formulated silver nanoparticles demonstrated significant antibacterial and antioxidant effects as a result of the presence of some secondary metabolites such as phenols, saponins, flavonoids and tannins in the leaves extract. [ABSTRACT FROM AUTHOR]

Background and Aim: The use of bioengineered nanocomposites as antimicrobials has increased in recent years, but very few investigations have been conducted to test their effectiveness against Pseudomonas aeruginosa, a pathogen presenting public health risks that can impact both humans and animals. The aim of this study was to assess the antimicrobial potential of phytofabricated silver nanoparticles synthesized using lemongrass extract against clinical isolates of P. aeruginosa. Materials and Methods: The extraction of active compounds from the leaves of Cymbopogon citratus was performed using ethanol (80%) as a solvent, high-performance liquid chromatography-mass spectrometry was used to analyze the chemical composition of the extract, the synthesis of silver nanoparticles (AgNPs) was done using silver nitrate (AgNO3) as a precursor, and the antimicrobial and antibiofilm activity of the extract and the AgNPs phytofabricated was assessed against 10 clinical strains of P. aeruginosa. Results: Lemongrass extract was found to consist of the following main compounds: Caffeic acid (445.21 ± 32.77 µg/g), p-coumaric acid (393.32 ± 39.56 µg/g), chlorogenic acid (377.65 ± 4.26 µg/g), quinic acid (161.52 ± 17.62 µg/g), and quercetin-3-glucoside (151.35 ± 11.34 µg/g). AgNPs were successfully phytofabricated using 2.5 mM AgNO3. The ultraviolet (UV)-visible absorption spectra of the AgNPs showed a localized surface plasmon resonance at 464 nm with an absorbance of 0.32 A. The 50× hydrodynamic diameter was 50.29 nm with a surface area value of 120.10 m2/cm3, and the volume mean diameter and Sauter mean diameter were 50.63 nm and 49.96 nm, respectively. Despite the compound found in lemongrass extract, no antimicrobial activity was observed with the extract, while AgNPs exhibited noteworthy dose-dependent antimicrobial activity with inhibition diameters up to 24 mm and minimum inhibitory concentration (MIC) and minimum bactericidal concentration ranging from 2 to 16 and 4-64 µg/mL, respectively. AgNPs also demonstrated significant antibiofilm activity by inhibiting biofilms up to 99% between MIC/2 and 2MIC. Conclusion: The present study suggests that lemongrass is a good candidate for the synthesis of AgNPs with good physicochemical characteristics and having a strong anti-pseudomonas activity. Further research is needed to assess the stability and safety of these AgNPs. [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]

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]

Much attention has been gained on green silver nanoparticles (green-AgNPs) in the medical field due to their remarkable effects against multi-drug resistant (MDR) microorganisms and targeted cancer treatment. In the current study, we demonstrated a simple and environment-friendly (i.e., green) AgNP synthesis utilizing Jacobaea maritima aqueous leaf extract. This leaf is well-known for its medicinal properties and acts as a reducing and stabilizing agent. Nanoparticle preparation with the desired size and shape was controlled by distinct parameters; for instance, temperature, extract concentration of salt, and pH. The characterization of biosynthesized AgNPs was performed by the UV-spectroscopy technique, dynamic light scattering, scanning electron microscopy, X-ray diffraction, and Fourier-transform infrared. The successful formation of AgNPs was confirmed by a surface plasmon resonance at 422 nm using UV-visible spectroscopy and color change observation with a particle size of 37± 10 nm and a zeta potential of −10.9 ± 2.3 mV. SEM further confirmed the spherical size and shape of AgNPs with a size varying from 28 to 52 nm. Antibacterial activity of the AgNPs was confirmed against all Gram-negative and Gram-positive bacterial reference and MDR strains that were used in different inhibitory rates, and the highest effect was on the E-coli reference strain (MIC = 25 μg/mL). The anticancer study of AgNPs exhibited an IC50 of 1.37 μg/mL and 1.98 μg/mL against MCF-7 (breast cancer cells) and A549 (lung cancer cells), respectively. Therefore, this green synthesis of AgNPs could have a potential clinical application, and further in vivo study is required to assess their safety and efficacy. [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]

A green, economical, highly efficient and easy method for the synthesis of AgNPs using dried black mulberry (Morus nigra L.) fruit extract was reported. Their formations were confirmed by both its brown color and the plasmon resonance band. The TEM analysis showed that they were in spherical shape with an average size of 6 ± 1 nm. In addition, they have exhibited excellent antibacterial activities against eleven different pathogenic bacteria. Finally, they have showed advanced catalytic activity against to methyl orange (MO), cresol red (CR) and methylene blue (MB) dyes both in unary and ternary mixture of dyes. In addition, the degradation of ternary dye mixture using the synthesized AgNPs was also tested using wastewater as the real sample. [ABSTRACT FROM AUTHOR]

Nanotechnology has emerged as a promising field for the development of novel antibacterial agents with reduced environmental impact. In this study, we present a novel green synthesis approach for the production of silver nanoparticles (AgNPs) using a plant-based extract. These AgNPs were subsequently characterized using various analytical techniques, including UV-Vis spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy (FTIR). UV-Vis spectroscopy confirmed the formation of AgNPs by exhibiting a characteristic surface plasmon resonance peak at around 401 and 420 nm. XRD analysis revealed the crystalline nature of the AgNPs, with distinct diffraction peaks corresponding to the face-centered cubic structure of silver. TEM analysis demonstrated that the synthesized AgNPs were predominantly spherical in shape and exhibited an average size within the nanoscale range. FTIR analysis was employed to elucidate the potential bioactive compounds present in the plant extract responsible for the reduction and stabilization of AgNPs. Furthermore, we evaluated the antibacterial activity of these synthesized AgNPs against a panel of bacterial isolates. All the bacterial isolates were sensitive to the silver nanoparticles. Staphylococcus aureus as found to be most resistant, while E. coli as found to be the most sensitive. [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]

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 green production of silver nanoparticles (AgNPs) produces AgNPs with minimum influence on the environment by using plant components such as alkaloids, carbohydrates, lipids, enzymes, flavonoids, terpenoids, and polyphenols as reducing agents. In the present investigation, Azadirachta indica leaf extract was used to form AgNPs from a 1 mM silver nitrate solution. The plan proved to be incredibly straightforward, cost‐effective, and effective. The production of the nanoparticles was observed visually, where the colorless fluid turns into a brown‐colored solution. Further research was carried out using x‐ray diffraction, Fourier‐transform infrared analysis, scanning electron microscopy, and transmission electron microscopy (TEM) in addition to UV–visible spectroscopy. The size range of AgNPs determined by TEM was 10–30 nm. When the diffusion technique was employed to demonstrate the antibacterial effect of AgNPs on various pathogens, the zones of inhibition for Staphylococcus aureus, Bacillus cereus, and Escherichia coli, when 50 g of AgNPs were used were 16, 12, and 17 mm, respectively. By examining the leakage of reducing sugars and proteins, the mechanism by which nanoparticle antibacterial properties were explored, showed that AgNPs were capable of lowering membrane permeability. [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]

There are several uses for silver nanoparticles in the field of biomedicine because of their exceptional features. The crucial use of silver nanoparticles is the development of antibiotics that are clinically effective against resistant bacteria. Due to their non-toxicity, environmental friendliness, and faster action, green syntheses of silver nanoparticles have gained some attraction. Plant extracts could be used as efficient sources of reductants and stabilizers in this process and also investigated for antibacterial action. This study mainly aimed to synthesize silver nanoparticles using Lablab purpureus flowers extracts and evaluate the antibacterial properties of the green synthesized sliver nanoparticles. The silver nanoparticles were synthesized and characterized by uv-vis, FT-IR spectroscopy and SEM analysis. Additionally, the disk diffusion method was used to evaluate the antibacterial activity of the silver nanoparticles against one gram positive and five gram negative bacteria. The particle size of synthesized Silver nanoparticles (AgNPs) was less than 1 µm. In bacterial susceptibility study, flower extract of L. purpureus showed moderate antibacterial activity but nanoparticles showed promising antibacterial potential against gram positive S. aureus and gram negative E. coli, moderate antibacterial activity against S. typhi bacteria, and mild activity against P. vulgaris, K. pneumonia and P. aeruginosa. This study indicates that AgNPs made from L. purpureus flower extract exhibit potent antibacterial activity, suggesting these nanoparticles may be used to develop effective anti-bacterial drugs for the treatment of bacterial infections. [ABSTRACT FROM AUTHOR]

In the present work, we report a simple, cost-efficient, and eco-friendly green method to synthesize silver nanoparticles with antimicrobial activity. An ethanolic extract from Moringa oleifera seed residue was used as a reducing and stabilizing agent in an aqueous solution of silver nitrate. The synthesized silver nanoparticles' hydrodynamic radius, polydispersity index, and zeta-potential were evaluated by Dynamic Light Scattering. Scanning Electron Microscopy was employed to confirm the size and morphology of the nanoparticles. Synthesis of spherical particles with 127 ± 24 nm was confirmed. After sintering, the product of the synthesis was analyzed by X-ray diffraction. The X-ray diffraction pattern attributed to reflections of the (111), (200), (220), and (311) planes, which are characteristic of silver nanoparticles, confirms the successful synthesis of crystalline face-centered cubic nanoparticles. The antimicrobial activity of the bionanoparticles was tested against Escherichia coli BL21(DE3) cells and compared with the effect of a Moringa oleifera seed cake extract. Herein, we show that the growth of Escherichia coli is significantly affected by the addition of the synthesized bionanoparticles. Addition of the bionanoparticles inhibited the growth and lengthened the lag phase of the bacterial culture. [ABSTRACT FROM AUTHOR]

Zinc nanoparticles (ZnNPs) are showing promising medical applications. However, their cytotoxicity is relatively high. This study aims to use a green synthesis technique based on the natural propolis (honeybees glue) and produce three counterparts of Zinc nanoparticles (ZnO-NPs, AuNPs@ZnO and AgNPs@ZnO). Then, the three would be analyzed for their potential antibacterial activity and cytotoxicity. The study compares the antibacterial activity and cytotoxicity of ZnO-NPs alone to its combination with gold and silver (AuNPs@ZnO and AgNPs@ZnO). The results showed that AgNPs@ZnO had contributed significantly to antibacterial activity against Gram-positive and Gram-negative bacteria. Moreover, AuNPs@ZnO and AgNPs@ZnO showed similar cytotoxicity to ZnO-NPs with higher safety. Furthermore, the Scanning and Transmission Electron Microscopes' micrographs (SEM and TEM) displayed the biosynthesized ZnNPs that have a spherical shape with sizes ranging from 17 to 70 nm, from 45 to 75 nm, and from 22 to 73 nm for ZnONPs, ZnO-AgNPs, free AgNPs, and ZnO-AuNPs, respectively. In addition, zeta potential values for ZnONPs were 11.4 mV, while ZnO-AgNPs and ZnO-AuNPs have a higher overall charge of 13.6 mV and 23.9 mV, respectively. Furthermore, ZnNPs exhibited antibacterial activity, yet AgNPs@ZnO demonstrated the highest antibacterial action against Gram-negative and Gram-positive bacteria. In addition, cytotoxicity analyses of biosynthesized ZnNPs on three cell lines; breast cancer cell (MCF-7), liver cancer cell (HepG-2) and Human skin fibroblast (HSF) revealed that Zn-NPs in a combination could function as an anticancer agent. Therefore, there are promising medical applications for the biosynthesized ZnNPs in combinations with other metals, such as ZnO-AgNPs, as safe antibacterial and anticancer medicines. [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 UV-visible, 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]

The biogenic synthesis of silver nanoparticles (AgNPs) has attracted many researchers due to their physical, chemical, optical, and biological properties, embracing a range of activities such as antibacterial, antifungal, anti-inflammatory, and anticancer activities. The purpose of this work is to synthesize and characterize AgNPs using Argyreia nervosa (AN) plant leaf extract, as well as to test their antimicrobial applications. In this work, silver nitrate (AgNO3) at 0.1 mM concentration and stable AgNPs were synthesized and observed by monitoring the color change of the solution from light yellow to brown. The UV–Vis spectrum shows a peak at 445 nm, confirming the formation of AN-AgNPs and Fourier transform infrared (FTIR) results confirm the presence of chemical groups which act as reducing agents stabilizing the AN-AgNPs and antimicrobial capping agents enhancing antimicrobial properties of AN-AgNPs. The crystalline behavior of these AN-AgNPs is confirmed through X-ray powder diffraction (PXRD) peaks. The morphology of AN-AgNPs and their sizes were studied (sizes range from 10 to 40 nm) using scanning electron microscopy (SEM). The disk diffusion assay shows the antimicrobial activity over Escherichia coli pathogenic microorganisms of clinical interest. The obtained results confirm a more significant antimicrobial effect of the biogenic AN-AgNPs maintaining low cytotoxicity. This work presents a potential way to produce non-toxic biogenic AgNPs with enhanced antibacterial activity, which can meet the increasing global demand for biogenic AgNPs as an alternative to antibiotics. [ABSTRACT FROM AUTHOR]

In this study, Ordered Mesoporous Carbon (OMC) was prepared using resol as a carbon precursor and F127 as a soft template. Small-angle X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) images, and nitrogen adsorption and desorption isotherms revealed that OMC possessed ordered hexagonal mesostructures (p6m) with an ordered pore size of 3.2nm, a high specific surface area (SBET) of 539m²/g, and a large total pore volume (Vtotal) of 0.44cm³/g. Subsequently, silver nanoparticles synthesized from an aqueous AgNO3 solution using glucose as a reducing agent and starch as a stabilizing agent were decorated on OMC, producing Ag/OMC. XRD analysis revealed that the composite contained silver crystals. In addition, the content and size of silver nanoparticles in Ag/OMC were 0.71wt% (AAS) and around 25-50nm (TEM), respectively. Due to the surface cover of silver nanoparticles, SBET and Vtotal of Ag/OMC slightly decreased to 417m²/g and 0.38cm³/g, respectively. Both agar and broth dilution techniques were used to evaluate the antibacterial activity of the material against Staphylococcus aureus. Ag/OMC with a Minimum Inhibitory Concentration (MIC) of 25.0µg/mL is a potential candidate for use against Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) were synthesized using the whole plant of Duchesnea indica (DI) which was extracted in different solvents; the antimicrobial effects of the extract were investigated in this study. The extraction of DI was performed using three different solvents: water, pure ethanol (EtOH), and pure dimethyl sulfoxide (DMSO). AgNP formation was monitored by measuring the UV–Vis spectrum of each reaction solution. After synthesis for 48 h, the AgNPs were collected and the negative surface charge and size distribution of the synthesized AgNPs were measured using dynamic light scattering (DLS). The AgNP structure was determined by high-resolution powder X-ray diffraction (XRD) and the AgNP morphology was investigated using transmission electron microscopy (TEM). AgNP antibacterial activities were evaluated against Bacillus cereus, Staphylococcus aureus, Escherichia coli, Salmonella enteritidis, and Pseudomonas aeruginosa using the disc diffusion method. Additionally, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were also determined. Biosynthesized AgNPs showed enhanced antibacterial activity against B. cereus, S. aureus, E. coli, S. enteritidis, and P. aeruginosa compared with that of pristine solvent extract. These results suggest that AgNPs synthesized from extracts of DI are promising antibacterial agents against pathogenic bacteria and can be further applied in the food industry. [ABSTRACT FROM AUTHOR]

Aqueous extract of Neolamarchia cadamba leaves were used in the synthesis of silver/silver chloride nanoparticles (Ag/AgCl NPs). Further they were separated based on their using step-wise centrifugation approach at 09,000, 12,000, and 15,000 rpm. Thus obtained NPs were characterized for their physicochemical features. NPs showed maximum absorbance at 455 nm, 415 nm, and 402 nm. All the NPs were found to be crystalline in nature with average crystallite size (nm) of 58.31, 23.43, and 09.56. Particle size distribution (nm) of NPs was observed to 435.43, 276.75, and 105.49, Surface charge (-mV) of NPs was observed to be 14.59, 23.90, and 32.17. Ag/AgCl NPs-rpm@15,000 showed antibacterial activity against Escherichia coli, coagulase-negative Staphylococci, and Staphylococcus aureus with zone of inhibition (mm) of 16.65, 13.69, and 14.02 at 50 µg per well, respectively. Ag/AgCl NPs-rpm@15,000 showed excellent catalytic activity in degradation of methyl red, methylene blue, rhodamine-B, and methyl orange dyes in the presence of sodium borohydride under 4, 6, 5, and 4 min with pseudo-first order rate constant (min−1) of 0.981 (96.4%), 0.666 (97.1%), 0.905 (98.1%), and 1.032 (96.6%), respectively. Furthermore, Ag/AgCl NPs-rpm@15,000 showed good catalytic efficiency even under different dye combinations. Total combination was degraded under 18 min. [ABSTRACT FROM AUTHOR]

The current work aimed to find substitutes for antibiotics because of the side effects of antibacterial agents and the expansion of bacterial resistance to these agents. The scope of this study was to evaluate the antibacterial activity of gold and silver nanoparticles (AuNPs and AgNPs) against selected animal pathogens (Staphylococcus aureus, Klebsiella pneumonia, Streptococcus pneumoniae, Escherichia coli, Bacillus abortus and Mycobacterium bovis). The synthesized nanoparticles were distinguished by scanning electron microscopy (SEM) analysis and tested for antibacterial activity with the broth microdilution method, well diffusion assay, and minimum bactericidal concentration procedure. Results showed that both AuNPs and AgNPs displayed good antibacterial activity against all tested bacteria. The strongest antibacterial action of AgNPS (18 mm) was against E. coli. AuNPs displayed good antibacterial activity against S. aureus and B. bovis with a suppression area of 14 mm. Therefore, it is suggested that AgNPs and AuNPs could be effectively used against animal pathogens and may contribute to reducing antibiotic resistance. However, there is a need for further research on the in vivo toxicity and mechanisms of action of AuNPs and AgNPs. [ABSTRACT FROM AUTHOR]

Green synthesis of nanoparticles is a latest and foremost technique to replace antibiotics against resistant strains of bacteria in forthcoming era. Nano particlesbased nanomedicine is the future of pharmaceutical industries. This study was designed to evaluate the antibacterial activity of green synthesis-based silver nanoparticles against an infection in rats. Salvia hispanica (S. hispanica) plant was used to reduce the silver nitrate (AgNO3) into silver nanoparticles (AgNPs). Reduction of silver nitrate into silver nanoparticles confirmed through the change of color from light yellow to deep brown of silver nitrate solution with S. hispanica seed extract. Characterization of silver nanoparticles was done through UV-Vis spectrophotometer, Atomic force Microscopy (AFM), Zeta size number, Zeta potential, Transmission Electron Microscopy and Scanning Electron Microscopy. S. hispanica based AgNPs were evaluated through agar well diffusion method, MIC (minimum inhibitory concentration) as well as against experimental infection in rats. UV-Vis spectrophotometer depicted wavelength at 420nm confirmed that particles were synthesized in Nano range. AFM showed spherical and square shapes nanoparticles with 80-120nm average size and 45mV charge. TEM were used to study spherical shape particle size 50-120nm at different resolution (100, 300, 500 nm). Similarly, SEM also depicted average particle size 80-130nm with spherical shape. Silver nanoparticles against enterotoxigenic Escherichia coli (ETEC) and Vibrio cholerae (V. cholerae) through a gar well diffusion method exhibited the greatest antibacterial activity against ETEC as compared to V. cholerae. The MIC against ETEC was 100µg/ml while MIC against V. cholerae was 25µg/ml. Finally, a single dose of AgNPs was administered orally to adult rats colonized with ETEC and V. cholerae, which significantly reduced the rate of colonization by the pathogens 75 or 100 folds, respectively. It was concluded that a S. hispanica based AgNPs have significant antibacterial effect, which may be considered as an effective alternate of antibiotics in future. [ABSTRACT FROM AUTHOR]

Wounds serve as an appropriate medium for the growth of pathogenic bacteria, and bacterial resistance to already available antibiotics demands new and safe approaches in the field of medicine. Silver nanoparticles (AgNPs) exhibited a wide range of applications in biomedicine and emerged as promising nano-antibiotics. The biological preparation of AgNPs by utilizing aqueous plant extract has become an encouraging alternative to traditional chemical methodologies, owing to a viable eco-friendly approach. In the present study, Lepidium didymum leaves extract was used for the biosynthesis of AgNPs-LD. The nanoparticles were characterized through UV-Vis spectroscopy, Fourier transforms infrared spectrometry (FTIR), Scanning electron microscopy (SEM), and X-ray diffraction (XRD). The antibacterial activity of AgNPs-LD was evaluated against Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia, and Pseudomonas aeruginosa. Further, AgNPs-LD nanoparticles were incorporated into topical gels to evaluate their effectiveness for wound healing in the rat model. UV-visible spectra showed a surface resonance peak around 400 nm correlated with the synthesis of AgNPs; FTIR spectra verified the participation of phytochemicals present in L. didymum leaves extract in AgNPs-LD synthesis; and SEM revealed dispersed spherical nanoparticles as well as aggregated clusters. XRD analysis confirmed the crystalline nature, face-centered cubic lattice, and average crystallite size of 21.42 nm. The AgNPs-LD showed promising antibacterial activity against tested strains with a maximum zone of inhibition against P. aeruginosa and showed accelerated wound healing capacity comparable to control and standard treatments over the time course of wound healing. The current study concluded that biosynthesized AgNPs-LD nanoparticles are effective as antibacterial agents and are promising novel wound healing products for clinical applications. [ABSTRACT FROM AUTHOR]

Nosocomial bacterial and fungal infections are one of the main causes of high morbidity and mortality worldwide, owing to the high prevalence of multidrug-resistant microbial strains. Hence, the study aims to synthesize, characterize, and investigate the antifungal and antibacterial activity of silver nanoparticles (AgNPs) fabricated using Camellia sinensis leaves against nosocomial pathogens. The biogenic AgNPs revealed a small particle diameter of 35.761 ± 3.18 nm based on transmission electron microscope (TEM) graphs and a negative surface charge of −14.1 mV, revealing the repulsive forces between nanoparticles, which in turn indicated their colloidal stability. The disk diffusion assay confirmed that Escherichia coli was the most susceptible bacterial strain to the biogenic AgNPs (200 g/disk), while the lowest sensitive strain was found to be the Acinetobacter baumannii strain with relative inhibition zones of 36.14 ± 0.67 and 21.04 ± 0.19 mm, respectively. On the other hand, the biogenic AgNPs (200 µg/disk) exposed antifungal efficacy against Candida albicans strain with a relative inhibition zone of 18.16 ± 0.14 mm in diameter. The biogenic AgNPs exposed synergistic activity with both tigecycline and clotrimazole against A. baumannii and C. albicans, respectively. In conclusion, the biogenic AgNPs demonstrated distinct physicochemical properties and potential synergistic bioactivity with tigecycline, linezolid, and clotrimazole against gram-negative, gram-positive, and fungal strains, respectively. This is paving the way for the development of effective antimicrobial combinations for the effective management of nosocomial pathogens in intensive care units (ICUs) and health care settings. [ABSTRACT FROM AUTHOR]

The growing multi-drug resistance in human disease causing pathogens is an issue of great concern, and there is a need for broad-spectrum antibiotic to fight severe diseases. As silver is toxic to microbes like fungi, bacteria and yeast, the use of silver nanoparticles as antimicrobial agent may help control the resistant pathogenic microbes. During this study, the bio-fabrication of silver nanoparticles was done from Artocarpus lakoocha fruit extract and characterized using various morphological and structural analysis. The agar well diffusion technique was performed to determine the bactericidal potential of nanoparticles against human disease causing pathogenic bacteria; finally, the anticancer activity was assessed by employing 96-well plate MTT assay and flow cytometry-assisted apoptosis on human prostate adenocarcinoma (PC-3) cells. The primary indication on nanoparticles synthesis was given by colour change from slight yellow to brown; further, reaffirmed by the peak obtained at 415 nm for absorption maximum in UV–vis. analysis. Meanwhile, the smooth surface and spherical shapes were determined by AFM and SEM analyses. Similarly, poly-dispersed distribution, size range of 6.59–25 nm and FCC crystalline nature were confirmed by TEM and XRD analyses. The silver nanoparticles displayed higher antibacterial activity by forming clear zones of inhibition and exhibited increased anticancer activity on PC-3 cells. The IC50 value obtained was 30.62 µg/ml and 48.11 ± 0.7%, 24.92 ± 0.5%, and 1.19 ± 0.4% of early, late apoptosis and necrosis was observed in flow cytometry-assisted Annexin V/PI study. The results obtained encourage the idea of using green AgNPs to cure microbial and cancer-related diseases in near future. [ABSTRACT FROM AUTHOR]

In recent years, research on silver nanoparticles (AgNPs) has attracted considerable interest among scientists because of, among other things, their alternative application to well-known medical agents with antibacterial properties. The size of the silver nanoparticles ranges from 1 to 100 nm. In this paper, we review the progress of research on AgNPs with respect to the synthesis, applications, and toxicological safety of AgNPs, and the issue of in vivo and in vitro research on silver nanoparticles. AgNPs' synthesis methods include physical, chemical, and biological routes, as well as "green synthesis". The content of this article covers issues related to the disadvantages of physical and chemical methods, which are expensive and can also have toxicity. This review pays special attention to AgNP biosafety concerns, such as potential toxicity to cells, tissues, and organs. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) have been widely studied due to their interesting physicochemical properties and remarkable antibacterial properties. Chemical synthesis methods, including green chemistry, have achieved 0D nanostructures. However, ecological methods have little studied self-assembling Ag nanostructures, such as flowers or dendrites. In this work, Ag dendrites and Ag flower-like morphologies have been successfully synthesized using a one-step green method employing Arctostaphylos pungens Kunth fruit extract at room temperature. The antibacterial properties of both nanostructures were evaluated against Gram-positive Escherichia coli and Gram-negative Staphylococcus aureus bacteria. Scanning electron microscopy (SEM), X-ray diffraction (XRD), ultraviolet–visible spectroscopy (UV–Vis), and infrared spectroscopy (IR) characterized the synthesized products. The morphological changes of the nanostructures come from the variation in the concentration of the precursor salt, silver nitrate (AgNO3). A growth mechanism is proposed that includes the formation of nanospheres and their subsequent transformation into Ag dendrites. Both nanostructures show good antibacterial activity against the tested microorganisms. The Ag dendritic nanostructures presented inhibition zones of 11 mm and 10.7 mm against Escherichia coli and Staphylococcus aureus bacteria. However, the flower-like structure was slightly less effective, presenting 11 and 9.5 mm inhibition zones against the same microorganisms, respectively. [ABSTRACT FROM AUTHOR]

The present study centers on the synthesis of ultra-small silver nanoparticles (AgNPs) with antibacterial properties using citrus peel residues (orange, lemon, and grapefruit) as reducing and stabilizing agents, and on assessing their antibacterial activity against multidrug-resistant clinical Staphylococcus aureus. The synthesized AgNPs were analyzed by various techniques, including UV-Vis spectroscopy, SAED, TEM, XRD, FTIR, and Raman. The results demonstrate the formation of ultra-small, monodisperse, quasi-spherical AgNPs with an average particle size of 2.42 nm for AgNPs produced with mixed extracts. XRD analysis indicated that the AgNPs have a crystal size of 9.71 to 16.23 nm. The AgNPs exhibited potent inhibitory activity against resistant S. aureus, with a minimum inhibitory concentration (MIC) of 15.625 to 62.50 ppm. The findings suggest that the ultra-small nanometer size of the AgNPs could be attributed to the synthesis method that employs ambient conditions and the presence of polyphenolic compounds from citrus peel. Consequently, AgNPs obtained through sustainable green synthesis hold significant potential in combating clinical multi-resistant bacterial strains that are challenging to treat and eradicate. This approach also contributes to the revaluation of citrus residues in the region, which is an ongoing environmental issue today. [ABSTRACT FROM AUTHOR]

The plant mediated biogenic synthesis of nanoparticles is of magnificent concern due to its eco-benign and single pot nature. Here, Cinnamomum tamala (C. tamala) aqueous leaf extract was utilised for the silver nanoparticles' (Ag NPs) synthesis. The phytoconstituents in the leaf extract were analysed by standard methods. These metabolites, especially carbohydrate polymers reduce Ag ions to Ag NPs accompanied by a reddish-brown coloration of the reaction mixture. The visual observation of intense brown colour is the first indication of the formation of Ag NPs. Various spectro-analytical techniques further characterise the Ag NPs. The green synthesised spherical Ag NPs were crystalline with an average size of 38 nm. The Ag NPs were scrutinised for antioxidant, antimicrobial and cytotoxic activity and obtained good results. The free radical scavenging was studied by 2, 2-Diphenyl-l-picrylhydrazyl (DPPH) assay. The antibacterial activity of Ag NPs was assessed against human pathogens, and it shown to have good antibacterial potency against a wide spectrum of bacteria. The cytotoxic activity against HEK-293T (human embryonic kidney) cell line was evaluated by 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay. These potent biological activities enable C. tamala capped Ag NPs to be suitable candidates for the future applications in various fields, predominantly clinical and biomedical. [ABSTRACT FROM AUTHOR]

Infections caused by Staphylococcus aureus and Klebsiella pneumoniae are becoming a common health issue throughout the world. Medicines that have been used to treat infections caused by these organisms are becoming obsolete due to the emergence of drug resistance at an alarming rate. Recently, the use of green synthesized nanoparticles has been gaining momentum as an alternative approach to combating microbial infections, since traditional methods for the synthesis of metal nanoparticles involve the use of toxic chemicals and the formation of harmful by‐products. In this study, an aqueous extract of the medicinal plant Prunella vulgaris is used for the synthesis of silver oxide nanoparticles (AgONPs). The formation of AgONPs is confirmed by UV‐visible spectroscopy in the wavelength range of 200–400 nm. X‐ray analysis of AgONPs shows crystallite size of the particles to be 36.9 nm. Scanning electron microscopic image shows the synthesized AgONPs are seemed to be spherical and oval in morphology with an average size of 55–182 nm, whereas FTIR spectroscopy of AgONPs reveal the presence of functional group. Finally, AgONPs are tested to be effective against S. aureus and k. Pneumoniae. [ABSTRACT FROM AUTHOR]

The silver nanoparticle is a good antibacterial material being used as a broad-spectrum fungicide, including against some multidrug-resistant strains. Compared with the normal chemical and physical preparation methods, green synthesis has attracted wide attention, because of the pharmaceutical activities of the natural product, mild reaction conditions, and environmentally friendly, etc. In this study, the synthesis of silver nanoparticles (Ag NPs) was prepared from Bletilla striata polysaccharide (BSP) and characterized by UV-vis spectroscopy and Dynamic Light Scattering (DLS). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicated the morphology of Ag NPs was subspherical with an average size of 20–35 nm. Bletilla striata polysaccharide not only can be used as a natural reducing agent, but also has good repairing ability. Moreover, the antibacterial experimental results showed its great antimicrobial activity against Gram-positive bacteria (Staphylococcus aureus), Gram-negative bacteria (Escherichia coli) and Candida albicans. [ABSTRACT FROM AUTHOR]

The synthesis of nanoparticles using medicinal plants is a potential pathway for developing environmentally friendly drugs with minimal side effects. The aim of this study was to isolate heptadecyl-trans-p-coumarate from the medicinal plant, Artemisia afra, utilise it and its extract to synthesise silver nanoparticles (AgNPs), zinc oxide nanoparticles (ZnONPs) and iron oxide nanoparticles (Fe2O3NPs) that were evaluated for antibacterial and cytotoxic activity. AgNPs synthesised from the coumarate and extract were mostly spherical with an average size of 12 nm and 29 nm, respectively. ZnONPs were mostly rods, plates and spheres with average sizes of 31 nm (extract) and 22 nm (coumarate). Fe2O3NPs were hexagons and spheres with average sizes of 31 nm (extract) and 24 nm (coumarate). Nanoparticles improved the antibacterial activity of the extract and coumarate against Escherichia coli, Pseudomonas aeruginosa, Chromobacterium violaceum and Staphylococcus aureus. Shape of nanoparticles influenced activity; rod-shaped ZnONPs and platelet-like Fe2O3NPs synthesised using the extract exhibited better antibacterial activity. Spherical ZnONPs synthesised using the coumarate and spherical AgNPs showed greater cytotoxicity. The results suggest a synergistic effect between the metal nanoparticles and capping agents. Overall, this study confirms the use of Artemisia afra for the biosynthesis of silver, zinc oxide and iron oxide nanoparticles. [ABSTRACT FROM AUTHOR]

This work focuses on the preparation of silver nanoparticles (AgNPs) by a green synthesis using the seed extract of Derris trifoliata. The optimum time and temperature for the extraction of seeds were determined using FTIR analysis. The seed extract acted as a reducing agent and silver nitrate was used as the metal precursor for the preparation of AgNPs. Optimization of reaction conditions for the preparation of AgNPs and its characterization was done by UV-Vis spectroscopy, FTIR, HRTEM and SAED images. The UV-Visible spectrum of AgNPs revealed a characteristic SPR peak at 433nm. HRTEM and SAED images confirmed nearly spherical nature of the AgNPs with a diameter of 2-20nm. H2O2 sensing capacity and the photocatalytic dye degradation of the AgNPs was investigated using UV-Vis spectroscopy. Antibacterial activity of silver nanoparticles on E-coli bacteria was also studied using microtitre plate method. [ABSTRACT FROM AUTHOR]

Aloe vera, Mentha arvensis (mint), Coriandrum sativum (coriander), and Cymbopogon citratus (lemongrass) leaf extracts were used to synthesize stable silver nanoparticles (Ag-NPs) by green chemistry. UV–vis spectrophotometry, X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) spectroscopy techniques were used to characterize these biosynthesized nanoparticles. The data indicated that the silver nanoparticles were successfully synthesized, and the narrower particle size distribution was at 10–22 nm by maintaining a specific pH. As a short-term post-sowing treatment, Ag-NP solutions of different sizes (10 and 50 ppm) were introduced to mung bean seedlings, and the overall increase in plant growth was found to be more pronounced at 50 ppm concentration. The antibacterial activity of Ag-NPs was also investigated by disc diffusion test, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) test. The zones of inhibition (ZOI) were shown by Escherichia coli (E. coli) (1.9, 2.1, 1.7, and 2 mm), followed by Staphylococcus aureus (S. aureus) (1.8, 1.7, 1.6, and 1.9 mm), against coriander, mint, Aloe vera, and lemongrass, respectively. MIC and MBC values of E. coli, and S. aureus ranged from 7 to 8 µg/mL. Overall, this study demonstrates that Ag-NPs exhibit a strong antimicrobial activity and thus might be developed as a new type of antimicrobial agent for the treatment of bacterial infection. [ABSTRACT FROM AUTHOR]

This study aimed to explain the production and the characterization of gelatin/poly(2-hydroxyethylmethacrylate-co-2-Acrylamido-2-methyl-1-propanesulfonic acid), Gel/p(HEMA-co-AMPS), hydrogels including silver nanoparticles (AgNP) that were developed with a simple, cost-effective and environmentally-friendly process. Silver ions were added to the Gel/p(HEMA-co-AMPS) hydrogel matrix synthesized via free radical polymerization, and silver nanoparticles were developed by in-situ reduction of silver ions (Ag+) in the swollen hydrogel using Verbascum Longipedicellatum plant extract. The structure and morphology of the prepared nanocomposite hydrogel were confirmed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy-energy-dispersive X-ray spectroscopy (TEM-EDX), X-ray diffraction analysis (XRD) and thermogravimetric analysis (TGA). In addition, the swelling properties of hydrogels were investigated and AgNPs embedded in the hydrogel network were found to absorb more water, improving the swelling properties of hydrogels. Finally, the antibacterial activity of silver nanocomposites against S. aureus, E. faecalis, B. Subtilis, B. cereus, E. coli, P. aeruginosa as bacterial agents and C. albicans as fungal agent was examined. Therefore, the present study offers a multi-component hydrogel containing AgNPs with low-cost and environmentally-friendly fabrication process for application as bactericidal materials in biotechnology and biomedical fields. [ABSTRACT FROM AUTHOR]

Plant tissues are regarded as rich sources of phytochemicals that can be used in the fabrication of nanometals. In this work, silver nanoparticles (AgNPs) are fabricated using an aqueous Poa bulbosa extract as an efficient reducing agent. The plasmon resonance peaks of the AgNPs recorded by UV–visible spectra during 25 min of the extract exposure to silver ions indicate a blue shift with the chemical reduction process. The FT‐IR spectrum of the Poa bulbosa extract shows the presence of chemical bonds of biomolecules that are involved in the reduction of Ag+ ions to AgNPs. The crystallite and particle sizes of AgNPs are estimated as 45.04 ± 13.6, 56.98 ± 13.08 and 43.14 ± 16.06 nm by XRD, SEM and TEM, respectively. DLS measurements showed a mean particle size of 119.26 ± 26.2 nm and zeta potential of −69.53 mV for the AgNPs indicating a proper colloidal stability. The most pronounced inhibition zone of antibacterial activity is found to be against Salmonella typhimurium, which is mainly attributed to the cell wall structure of the Gram‐negative strains. This is also demonstrated in the minimum inhibitory concentration (MIC) of 1.6 μg/mL in case of S. typhimurium. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) biosynthesized using aqueous medical plant extracts as reducing and capping agents show multiple applicability for bacterial problems. The aim of this study was to expand the boundaries on AgNPs using a novel, low-toxicity, and cost-effective alternative and green approach to the biosynthesis of metallic NPs using Calendula officinalis (Calendula) and Hyssopus officinalis (Hyssopus) aqueous extracts. The formation of AgNPs was confirmed by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) techniques. The effectiveness of biosynthesized AgNPs in quenching free radicals and inhibiting the growth of Gram-positive and Gram-negative microorganisms was supported by in vitro antioxidant activity assay methods and using the Kirby–Bauer disk diffusion susceptibility test, respectively. The elucidated antimicrobial and antioxidative activities of medical plant extracts were compared with data from the engineered biosynthetic AgNPs. The antimicrobial effect of engineered AgNPs against selected test cultures was found to be substantially stronger than for plant extracts used for their synthesis. The analysis of AgNPs by TEM revealed the presence of spherical-shaped nano-objects. The size distribution of AgNPs was found to be plant-type-dependent. The smaller AgNPs were obtained with Hyssopus extract (with a size range of 16.8 ± 5.8 nm compared to 35.7 ± 4.8 nm from Calendula AgNPs). The AgNPs' presumably inherited biological functions of Hyssopus and Calendula medical plants can provide a platform to combat pathogenic bacteria in the era of multi-drug resistance. [ABSTRACT FROM AUTHOR]

In order to solve the problems of rubropunctatin insoluble in water and its low bioavailability, and explore the synthesis method of green silver nanoparticles, rubropunctatin was used as reducing agent and blocking agent, rubropunctatin-functionalized silver nanoparticles (R-AgNPs) were successfully synthesized. The distinctive absorption peak at 410 nm confirmed the formation of R-AgNPs. Zeta potential measurement showed excellent stability of R-AgNPs with negative values of −29.81 ± 0.37 mV. The results of TEM and XRD showed that the prepared R-AgNPs were round, well dispersed and crystallized with average particle size of 13.54 ± 0.42 nm. FT-IR and XPS studies show that functional groups are involved in R-AgNPs synthesis. The antibacterial activity of R-AgNPs was compared with commercial silver nanoparticles (AgNPs) by microdilution method. The results showed that R-AgNPs (MIC 7.81 μg/mL) has stronger antibacterial activity than commercial AgNPs. The bacteria morphology was observed by the live and dead (SYTO 9/PI) staining assay and SEM showed that the antibacterial effect of R-AgNPs was caused by the destruction of the bacterial cell membrane. Cytotoxicity of rubropunctatin-functionalized silver nanoparticles and commercial silver nanoparticles on mouse fibroblast 3T3 cells was assessed by CCK-8 assay. The results showed that the toxicity of rubropunctatin-functionalized silver nanoparticles to 3T3 cells was lower than that of commercial silver nanoparticles. In summary, synthesis of silver nanoparticles using rubropunctatin is a green synthesis method, and R-AgNPs is a potential antibacterial agent. [ABSTRACT FROM AUTHOR]

Nanotherapeutic agents play a crucial role in medicine and the bio-nanotechnology field. Because of its cost-effectiveness, plant-based nanoparticle production has sparked a lot of attention, sustainable way, eco-friendly nature, and a plethora of applications. In the present study, the antioxidant and antimicrobial potential of silver nanoparticles (AgNPs) of aqueous extract of Nigella Sativa seeds have been investigated. AgNPs synthesized using N. Sativa extract, characterized by UV-Vis spectroscopy, FTIR, X-ray diffraction (XRD), SEM, and energy dispersive spectroscopy (EDX) techniques showed a peak at 430 nm, with size ranging between 12.97 and 16.37 nm with a spherical shape. Three assays were used to test the antioxidant activity of biosynthesized silver nanoparticles: DPPH, FRAP, and TAC radical scavenging assays, all of which showed strong antioxidant capacity. The disk diffusion method was used for determining the antimicrobial activity of AgNPs. Evaluation of the antimicrobial potential of biosynthesized AgNPs registered the highest inhibitory activity against S. aureus (17.38 mm) followed by E. coli (16.45 mm), B. subtilis (15.5 mm), P. aeruginosa (14.6 mm), and S. Typhimurium (14.35 mm). It was noted that the increased extract concentration in biosynthesized AgNPs leads to a higher zone of inhibition. These results indicated that AgNPs have an effective and strong antimicrobial activity that provides a marvelous source for the development of a new antibacterial drug that can be used for solving the problem of microbial resistance. [ABSTRACT FROM AUTHOR]

Nanoparticles are molecules in the range of 1 nm to 100 nm and they can be synthesized by physical, chemical and biological methods. Green synthesis involves the production of nanoparticles from bacteria, fungi, algae, plants and plant extracts. Plant extracts with their chemical constituents can capture the target metals from their salt solution and transform the metal particles into nanoparticles with the cellular catalysts. The present study focuses on the green synthesis of silver nanoparticles using the liquid endosperm of coconut, the coconut water (Cocos nucifera), Liquid endosperm of palm fruit (Borassus flabellifer) and coconut Toddy as the reducing agent. The bio-reduction of aqueous silver ions by coconut water is identified by its colour change. During the synthesis of silver nanoparticles, the colour of the solution changed from milky white to brown. The characterization of synthesized AgNPs (Silver Nanoparticles) was done by Fourier Transform Infrared Spectroscopy and UV-Vis Spectroscopy. The peaks obtained at 250 and 350 nm confirmed the presence of synthesized Silver Nanoparticles. The antibacterial activity of the synthesized nanoparticles was studied on Escherichia coli, Staphylococcus aureus and Streptococcus pyogenes using disc diffusion method. The recent approach of green synthesis is quite impressive due to its eco- friendly, economical, feasible and non- toxic nature. [ABSTRACT FROM AUTHOR]

[Display omitted] • First time report on green-synthesis of AgNPs using aqueous extract of S. sisymbriifolium fruits. • The characterization studies were employed to elucidate the physical properties of AgNPs. • The synthesized AgNPs possessed profuse antioxidant and antibacterial activity in comparison to crude extract. • The green-synthesized AgNPs exhibited strong degradation of methylene blue under solar and UV-irradiations. The present research work focused on biological synthesis of silver nanoparticles using Solanum sisymbriifolium aqueous fruit extract (AgNPs@SsFE) and determining their pharmaceutical and environmental aspects for the first time. The phytochemicals extracted from S. sisymbriifolium fruit extract (SsFE) contributed in reducing the average particle size of green synthesized AgNPs@SsFE to 23.17 nm and served as capping agents. Further, when AgNPs@SsFE were characterized using PSA, ZP, FE–SEM, Elemental mapping, EDX, HR–TEM, SAED, FTIR and XRD, exhibited the high colloidal stability, spherical shape and crystalline nature of the nanoparticles. Moreover, the synthesized AgNPs@SsFE exhibited enhanced antioxidant activity in comparison to SsFE when assayed via DPPH, FRAP, •NO and H 2 O 2 scavenging methods. The Agar well–diffusion analysis unveiled AgNPs@SsFE to possess greater antibacterial activity against highly pathogenic gram–negative strains than gram–positive strains. Besides, the synthesized AgNPs@SsFE established itself to be a strong photocatalyst by degrading the methylene blue cationic dye under Solar and UV irradiations. These features of synthesized AgNPs@SsFE are found promising to convince the efficacy of SsFE in synthesizing the nanoparticles which can be useful in modern medicine and clinical applications. [ABSTRACT FROM AUTHOR]