Antibacterial and antibiofilm effects of green synthesized selenium nanoparticles on clinical Klebsiella pneumoniae isolates.

Nanotechnology covers many disciplines, including the biological sciences. In this study, selenium nanoparticles (Se-NPs) were synthesized using Artemisia annua extract and investigated against clinical strains of klebsiella pneumoniae (K. pneumoniae) for their anti-biofilm effects. In this experimental study, from May 1998 to September 1998, 50 clinical samples of blood, urine, and sputum were collected, and K. pneumoniae strains were isolated using microbiological methods. Subsequently, the antibacterial effects of Se-NPs at concentrations of 12-25-50-100/5-6/3-25/125 µg/mL were studied. Finally, biofilm-producing strains were isolated, and the expression of mrkA biofilm gene was studied in real-time strains treated with Se-NPs using real-time polymerase chain reaction (PCR). Out of 50 clinical samples, 20 strains of K. pneumoniae were isolated. Minimum inhibitory concentration (MIC) results of Se-NPs showed that Se-NPs were capable of significant cell killing. Real-time PCR results also showed that mrkA gene expression was significantly reduced in strains treated with Se-NPs. According to this study, Se-NPs could reduce bacterial growth and biofilm formation, therefore, could be considered a candidate drug in the medical application for infections caused by K. pneumoniae.

Preparation and modification of forcespun polypropylene nanofibers for adsorption of uranium (VI) from simulated seawater.

In this paper, polypropylene (PP) nanofibers were prepared using the melt forcespinning technology by a handmade device. Then, the surface of PP nanofibers was grafted through the high energy electron beams (EB) pre-irradiation method by acrylonitrile and methacrylic acid monomers with grafting percentage of 145.55%. The 92% of grafted cyano functional groups on nanofibers were converted to amidoxime groups, then modified by an alkaline solution. Characterization and surface morphology of nanofibers were investigated by Fourier Transform Infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The produced adsorbent was used to adsorb U(VI) ions from simulated seawater. The maximum adsorption was 83.24 mg/g in the optimal time of 60 min and optimal pH of 4. The optimum desorption efficiency was 80% in HCl 0.5 M. The kinetic data in optimum conditions showed that the adsorption followed an S-shaped kinetic model. The Adsorption equilibrium studies presented S-shape isotherm model that confirmed the adsorption occurs both on the adsorbent surface and in its pores The thermodynamic studies indicated spontaneous adsorption of uranyl ions and the higher efficiency adsorption at higher temperatures. The selectivity of adsorbent for metal ions followed the order V(V)>U(VI)>CO(II)>Ni(II)>Fe(II). These results shows that the prepared and modified nanofibers in this work can be considered as an effective and promising adsorbents for removal of uranium ions from seawater with high efficiency.

Antibiofilm effect of green engineered silver nanoparticles fabricated from Artemisia scoporia extract on the expression of icaA and icaR genes against multidrug-resistant Staphylococcus aureus.

Silver nanoparticles (AgNPs) are at the forefront of the swiftly developing scope of nanotechnology. In the current study, we investigated the green synthesis of AgNPs using Artemisia scoporia as a reducing and capping agent. The biosynthesized AgNPs were characterized using ultraviolet-visible spectroscopy, X-ray diffraction, Fourier-Transform infrared spectroscopy, dispersive absorption spectroscopy, scanning electron microscopy, and transmission electron microscopy. The efficacy of the nanoparticle synthesis was assessed by comparing the antibiofilm activity with commercial AgNPs. The effect of sub-minimum inhibitory concentrations (MICs) of AgNPs on biofilm formation was determined by microtiter plate assay. The expression level of the icaA and icaR genes was assessed by real-time polymerase chain reaction assay. The structural and functional aspects of AgNPs were confirmed. The expression levels of icaA and icaR in the isolates exposed to sub-MIC of both commercial and biosynthetic AgNPs were lower and higher than in the control group, respectively. Our results also indicated that greater reduction and induction in icaA and icaR gene expression were noticed with the sub-MIC doses of biosynthetic AgNP versus commercial AgNP, respectively. This study suggested the application of AgNPs as a significant therapeutic and clinical option in the future and usage for fabricating medical implants. Nevertheless, further investigation is required for examining the pharmaceutical and medicinal properties of AgNPs.

Antioxidant, antibacterial and anticancer properties of phyto-synthesised Artemisia quttensis Podlech extract mediated AgNPs.

The focus of this study is on a rapid and cost-effective approach for the synthesis of silver nanoparticles (AgNPs) using Artemisia quttensis Podlech aerial parts extract and assessment of their antioxidant, antibacterial and anticancer activities. The prepared AgNPs were determined by ultraviolet-visible spectroscopy, X-ray diffraction, Fourier transform infra-red spectroscopy, transmission electron microscopy, scanning electron microscopy, energy-dispersive spectroscopy, and dynamic light scattering and zeta-potential analysis. The AgNPs and A. quttensis extract were evaluated for their antiradical scavenging activity by 2, 2-diphenyl, 1-picryl hydrazyl assay and anticancer activity against colon cancer (human colorectal adenocarcinoma cell line 29) compared with normal human embryonic kidney (HEK293) cells. Also, the prepared AgNPs were studied for its antibacterial activity. The AgNPs revealed a higher antioxidant activity compared with A. quttensis extract alone. The phyto-synthesised AgNPs and A. quttensis extract showed a dose-response cytotoxicity effect against HT29 and HEK293 cells. As evidenced by Annexin V/propidium iodide staining, the number of apoptotic HT29 cells was significantly enhanced, following treatment with AgNPs as compared with untreated cells. Besides, the antibacterial property of the AgNPs indicated a significant effect against the selected pathogenic bacteria. These present obtained results show the potential applications of phyto-synthesised AgNPs using A. quttensis aerial parts extract.

Phytochemical composition and biological activities of Artemisia quettensis Podlech ethanolic extract.

The present study aim to investigate the phytochemical composition, antibacterial, antioxidant and anticancer activities of the ethanolic extract from aerial parts of Artemisia quettensis Podlech. The aerial part of A. quettensis Podlech extract was used for Gas chromatography-mass spectrometry (GC-MS) analysis, antioxidant, antibacterial and anticancer activities. GC/MS analysis of extract from this plant showed 23 major components and the most dominant components were acetic acid, [4-(1-hydroxy-1-methylethyl) cyclohex-1-enyl] methyl ester (13.88%), trans-Phytol (10.06%) and 2,6-Dimethyl-2,6-octadiene-1,8-diol diacetate (6.8%). The extract had significant antibacterial and anticancer effects. The highest percentage of antioxidant activity was 78.46% at 2 mg/mL concentration of extract. Moreover, the highest antibacterial effects of extract were against to gram-positive bacteria and the IC50 cell cytotoxicity value on HT29 cell line in 24 h, 48 h and 72 h were 31.54, 6.08 and 2.96 mg/mL, respectively. From this study, A. quettensis Podlech could be considered as a promising source for novel drug compounds.

Chemical composition, antioxidant, antibacterial and cytotoxic effects of Artemisia marschalliana Sprengel extract.

The present study was to investigate the gas chromatography/mass spectrometry (GC/MS), in vitro antioxidant, antibacterial and anticancer activity of the ethanolic extract from aerial parts of Artemisia marschalliana Sprengel against human gastric carcinoma (AGS) and L929 cell lines. Phytochemical analysis of A. marschalliana Sprengel extract showed 22 major components and the most dominant compounds were trans-phytol (29.22%), α-Linolenic acid (13.47%) and n-Hexadecanoic acid (9.28%). In addition, the antioxidant and anticancer activity of A. marschalliana Sprengel extract were evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) methods, respectively. Antibacterial activity against selected pathogenic bacteria was also determined. According to the present obtained results, it seems that this plant has potential uses for pharmaceutical industries and further studies of pharmaceutical importance were suggested to be performed on A. marschalliana Sprengel.