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The impressive role of silver nanoparticles (AgNPs) is well identified for cancer therapy. However, safety concerns have been raised about the adverse effects of high-doses of chemically-synthesized-AgNPs that release many hazardous residues and in turn diminish the anticancer property of AgNPs. Hence, to overcome these side effects and to maintain the anticancer effectiveness of AgNPs at relatively low-doses, the present study utilizes a natural antitumor product Ferula asafoetida (FA) in the preparation of green synthesis of AgNPs and further focuses on its cytotoxic effects, against Lung and Cervical cancer cells. The successful green-synthesis of FA-AgNPs was confirmed via UV–Vis-spectroscopy, TEM, DLS, FTIR and IR. Based on cytotoxicity assay, the average low (6.25 µl) and high (25 µl) doses of FA-AgNPs were observed to cause severe cytotoxic effects on studied cancer cells. Furthermore, our study was also directed to check any possible antitumorigenic-modulatory-effects of low and high doses of FA-AgNPs on the expression of four oncogenes (PIK3CA, KRAS, EGFR and ERBB3). In RT-qPCR analysis, the low and high doses of FA-AgNPs caused significant(p < 0.01) downregulation effects on the expression of PIK3CA and KRAS oncogenes, in treated-cancer cells. This is the first-report on the role of FA-AgNPs that induce strong cytotoxicity with its low-doses. [ABSTRACT FROM AUTHOR]

In this study, silver nanoparticles were synthesized by a novel, environmentally friendly method using low-pressure cold plasma in different ways: for chemical and green synthesis. The "traditional" Ag NP capping agents (sodium citrate, sodium alginate, poly(vinyl alcohol), polyvinylpyrrolidone, Tween-80, sodium carboxymethyl cellulose, and "green" stabilizers (grape and orange pomace) were used in the researched synthesis methods. The synthesized Ag NPs were characterized through different techniques such as UV–Vis, DLS-method, SEM HR-TEM for morphology parameter investigation. It was established that the manifestation of antiradical activity (DPPH method) (30–80% in concentrations of 0.1–1.5 mg/mL) is ensured only when using "green" types of stabilizers, and in this case, the method of synthesis and characteristics of NPs are not of decisive importance. Experimental data and theoretical quantum-chemical calculations have shown that the intensity of the antiradical effect of "green" stabilizers (grape and orange pomace) is largely determined by the content of phenolic and polyphenolic compounds (LC–MS method). The type of stabilizer, which determines the size of the NPs and the zeta potential, has a decisive influence on the intensity of the manifestation of antimicrobial properties. The latter determines the rate of release of silver ions and the intensity of antimicrobial action. [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]

Pollution of water by leaking industrial dyes has become a major problem for aquatic organisms and human-being. Polluted water treatment methods need efficient alternatives to conventional dye removing techniques. In this study, the catalytic activity of cellulose based silver nanocomposite against the pollutant methylene blue dye was searched. Cellulose based silver nanocomposite was synthesized by using in situ green synthesis method with Laurus nobilis extract. UV–VIS, FTIR, SEM, TEM, EDS, XRD, BET analyses were used to characterization of synthesized nanocomposite. Electron microscopy results confirmed that 25 nm diameter silver nanoparticles were supporting the 25 nm width cellulose nanofibers. Elemental composition of confirmed by UV–VIS, FTIR, XRD and EDS results which including silver and cellulose specific peaks. BET results showed that nanocomposite have 11.1 nm pore size with 199,8508 m2/g specific surface area. Catalytic activity of nanocomposite was performed against methylene blue in the presence of NaBH4. Catalytic activity was traced for up to 120 min and complete removal of methylene blue dye was estimated as 1 h. Moreover, the recycled nanocomposite was found reusable without activity loss for three times. These results offer an easy, eco-friendly and reusable dye removing material for wastewaters which were polluted by industrial dyes. [ABSTRACT FROM AUTHOR]

Gastric cancer is a major human health threat and finding novel and effective anticancer compounds against it is crucially important. Silver nanoparticles (NPs) have promising anticancer potential with minimal side effects. Functionalization of Ag NPs with magnetic compounds could provide novel features, including targeted drug delivery and photothermal therapy. In this work, green synthesis and characterization of MgFe2O4@Ag nanocomposite were performed. The anticancer potential of the nanocomposite against adenocarcinoma gastric (AGS) cells was investigated using MTT, flow cytometry, Hoechst staining, and caspase-3 activation assays. Also, the relative expression of the Bax and Bcl-2 genes in nanocomposite treated cells was investigated. Proper synthesis and crystallinity of the MgFe2O4@Ag NPs were confirmed by the Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses. Scanning and transmission electron microscopy indicated the spherical shape of the NPs with the size range of 23–53 nm. Lack of elemental impurities and good stability of the NPs was confirmed by energy dispersive X-ray (EDX) mapping and measuring zeta potential (− 35.5 mv), respectively. The MgFe2O4@Ag NPs showed a significantly higher antiproliferative potential against AGS cells (IC50 = 43 µg/mL), than human embryonic kidney cells (HEK293) cells (IC50 = 158 µg/mL). Moreover, flow cytometry and Hoechst staining confirmed apoptosis induction in treated AGS cells. Also, the activity of the caspase-3 protein and expression of the Bax gene among MgFe2O4@Ag treated cells was significantly increased to 1.8 and 1.21 folds, respectively, while the Bcl-2 gene was down-regulated to 0.68 folds. This study revealed the promising anticancer potential of MgFe2O4@Ag NPs to be used for gastric cancer treatment after further characterization using in-vitro and in-vivo assays. [ABSTRACT FROM AUTHOR]

In order to investigate the physicochemical properties and bioactivities of AgNPs prepared using green and chemical approaches and further explore the related antibacterial mechanism, one kind of chemical AgNPs (C-AgNPs) and three kinds of green AgNPs (G-AgNPs) mediated with aqueous extracts of Morus alba L. were prepared and characterized. All G-AgNPs displayed higher antioxidant activities in DPPH radical scavenging, reducing power and total antioxidant assays than C-AgNPs and extracts. Meanwhile, all G-AgNPs exerted significantly (P < 0.05) enhanced antimicrobial activities against various pathogens compared with C-AgNPs and extracts. Among prepared AgNPs, ML-AgNPs mediated with aqueous extract of Morus alba L. leaves exhibited the most powerful antibacterial effect with the largest inhibition zones (13.11 ± 0.76 mm for S. aureus, 13.27 ± 0.22 mm for E. coli) and the lowest minimum inhibition concentrations against S. aureus (6.125 μg/ml) and E. coli (3.125 μg/ml). ML-AgNPs could inhibit the growths of S. aureus and E. coli in time- and dose-dependent modes, and even could disrupt the bacterial structure integrality resulting in the leakage of intracellular contents. G-AgNPs, especially ML-AgNPs, with remarkable bioactivities could replace C-AgNPs as related agents applied in agriculture and medicine. [ABSTRACT FROM AUTHOR]

Delonix regia has bioactive phytochemicals present in leaves, seeds, roots, and flowers. Considering that these compounds are common in extracts used for silver nanoparticles (AgNPs) biosynthesis, this study investigated the potential of D. regia seeds aqueous extract (DRE) in different concentrations to produce AgNPs (DRE-AgNPs). DRE composition was investigated by qualitative assays, and physico-chemical/structural characterization of AgNPs was performed by UV–Visible spectroscopy, dynamic light scattering (DLS), Zeta potential, and atomic force microscopy (AFM). Antibacterial effect of DRE-AgNPs was evaluated against Escherichia coli and Staphylococcus aureus. DRE presented mainly tannins and saponins. Additionally, the absorbance of each DRE-AgNPs was positively correlated to DRE concentration. At higher DRE concentrations, AgNPs were larger, regarding Z average; tended to monodispersity; and presented more negative Zeta potentials. Hydrodynamic diameters of DRE-AgNPs were measured by number distribution and only AgNPs synthesized with DRE 2 mg ml−1 (DRE-AgNPs 2) presented a single population of particles. Thus, DRE-AgNP 2 was analyzed by AFM and exhibited a spherical shape and an average height of 18.39 ± 1.59 nm. Most of DRE-AgNPs presented antibacterial effects against E. coli and S. aureus at 128 or 256 µmol l−1. In conclusion, different DRE concentrations modulated physico-chemical characteristics of AgNPs with antibacterial activity. [ABSTRACT FROM AUTHOR]