scholarly journals Evaluation of Samarium Doped Hydroxyapatite, Ceramics for Medical Application: Antimicrobial Activity

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
C. S. Ciobanu ◽  
S. L. Iconaru ◽  
C. L. Popa ◽  
M. Motelica-Heino ◽  
D. Predoi
Keyword(s):  
Electron Microscopy ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Enterococcus Faecalis ◽  
Medical Application ◽  
Inhibitory Effect ◽  
Linear Increase ◽  
High Antibacterial Activity ◽  
Hydroxyapatite Ceramics ◽  
Transmission Electron

Samarium doped hydroxyapatite (Sm:HAp),Ca10-xSmx(PO4)6(OH)2(HAp), bionanoparticles with differentxSmhave been successfully synthesized by coprecipitation method. Detailed characterization of samarium doped hydroxyapatite nanoparticles (Sm:HAp-NPs) was carried out using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR). The biocompatibility of samarium doped hydroxyapatite was assessed by cell viability. The antibacterial activity of the Sm:HAp-NPs was tested against Gram-negative bacteria (Pseudomonas aeruginosaandEscherichia coli) and Gram-positive bacteria (Enterococcus faecalisandStaphylococcus aureus). A linear increase of antimicrobial activity ofP. aeruginosahas been observed when concentrations of Sm:HAp-NPs in the samples withxSm=0.02were higher than 0.125 mg/mL. For Sm:HAp-NPs withxSm=0.05a significant increase of antibacterial activity onE. coliwas observed in the range 0.5–1 mg/mL. For low concentrations of Sm:HAp-NPs (xSm=0.05) from 0.031 to 0.125 mg/mL a high antibacterial activity onEnterococcus faecalishas been noticed. A growth of the inhibitory effect onS. aureuswas observed for all concentrations of Sm:HAp-NPs withxSm=0.02.

scholarly journals Fortunella japonica extract as a reducing agent for green synthesis of silver nanoparticles

2018 ◽  
Vol 7 (3) ◽  
pp. 1570
Author(s):  
Nguyen Phung Anh ◽  
Truong Thi Ai Mi ◽  
Duong Huynh Thanh Linh ◽  
Nguyen Thi Thuy Van ◽  
Hoang Tien Cuong ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Volume Ratio ◽  
Diffusion Method ◽  
High Antibacterial Activity ◽  
Agno3 Solution ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Average Size

A rapid way of synthesizing silver nanoparticles (AgNPs) by treating Ag+ ions with a green Fortunella Japonica (F.J.) extract as a combined reducing and stabilizing agent was investigated. The reaction solutions were monitored using UV-Vis spectroscopy, the size and shape of crystals were determined by scanning electron microscopy and transmission electron microscopy, the crystalline phases of AgNPs were presented by X–ray diffraction, and the relation of nanoparticles with Fortunella Japonica extract was confirmed using fourier transform infrared spectroscopy. The results indicated that no formation of AgNPs had taken place in the dark during 24 hours at room temperature and 40 oC. Meanwhile, it was found that the rate of AgNPs formation increased rapidly under the sunlight. The effects of the synthesis factors on the AgNPs formation were investigated. The suitable conditions for the synthesis of AgNPs using F.J. extract were determined as follows: F.J. extract was mixed with AgNO3 1.75 mM solution with the volume ratio of 3.5 AgNO3 solution/1.5 F.J. Extract, stirred 300 rpm for 150 minutes at 40 oC under sunlight illumination. At these conditions, AgNPs showed high crystalline structure with the average size of 15.9 nm. The antibacterial activity of silver nanoparticles was determined by agar well diffusion method against E. coli and B. subtilis bacteria. The green synthesized AgNPs performed high antibacterial activity against both bacteria.  

scholarly journals Antifungal Factor Produced by Pseudomonas fluorescens against an Endophytic Fungus

1970 ◽  
Vol 9 ◽  
pp. 65-71 ◽  
Author(s):  
Rajani Malla ◽  
Suprada Pokharel
Keyword(s):  
Electron Microscopy ◽  
Pseudomonas Fluorescens ◽  
Endophytic Fungus ◽  
Plant Growth Promoting Rhizobacteria ◽  
Inhibitory Effect ◽  
Piriformospora Indica ◽  
Antifungal Substance ◽  
Transmission Electron ◽  
Inhibitory Compound ◽  
Plant Growth Promoting

Growth characteristics of Piriformospora indica an endophytic fungus with plant growth promoting rhizobacteria in an aspergillus medium were studied. P. indica showed promotional effects with species of Azotobacter chroococcum, Azospirillum brasilensis, Bradyrhizobium spp., and inhibitory effect with Pseudomonas fluorescens. The biochemical and molecular level of inhibitory factor produced by P. fluorescence suggests that the antifungal substance was thermolabile and the protease test showed it to be protease resistant in nature. Dialysis test indicated that this substance had a molecular weight of more than 12,000 kDa. The inhibitory substance turns out to be 'fungistatic' as well as 'fungicidal' in nature. Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) studies showed the cell wall in damaged form suggesting the high potency of this antifungal substance. The inhibitory compound produced by P. fluorescence was suspected to be pyoverdine, a kind of siderophore, an iron containing substance. Key words: Pseudomonas fluorescens; Piriformospora indica; siderophore; rhizobacteria; TEM; SEM DOI: 10.3126/njst.v9i0.3167 Nepal Journal of Science and Technology 9 (2008) 65-71

scholarly journals Potential Decontamination of Drinking Water Pathogens through k-Carrageenan Integrated Green Bottle Fly Bio-Synthesized Silver Nanoparticles

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1936 ◽  
Author(s):  
M. A. Abu-Saied ◽  
Mohamed Elnouby ◽  
Tarek Taha ◽  
Muhammad El-shafeey ◽  
Ali G. Alshehri ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Drinking Water ◽  
Pathogenic Bacteria ◽  
Polymeric Nanoparticles ◽  
Wide Distribution ◽  
Spectrophotometric Analysis ◽  
Transmission Electron ◽  
Green Bottle

The wide distribution of infections-related pathogenic microbes is almost related to the contamination of food and/or drinking water. The current applied treatments face some limitations. In the current study, k-carrageenan polymer was used as supporting material for the proper/unreleased silver nanoparticles that showed strong antimicrobial activity against six pathogenic bacteria and yeast. The bio-extract of the pupa of green bottle fly was used as the main agent for the synthesis of silver nanoparticles. The qualitative investigation of biologically synthesized silver nanoparticles was determined using UV-Vis spectrophotometric analysis; however, the size of nanoparticles was in range of 30–100 nm, as confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and particle size analyzer. The proper integration of silver nanoparticles into the polymeric substrate was also characterized through fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), SEM, and tensile strength. The antimicrobial activity of k-carrageenan/silver nanoparticles against Gram positive, Gram negative, and yeast pathogens was highly effective. These results indicate the probable exploitation of the polymeric/nanoparticles composite as an extra stage in water purification systems in homes or even at water treatment plants.

scholarly journals Biosynthesized gold nanoparticles-doped hydroxyapatite as antibacterial and antioxidant nanocomposite

2021 ◽  
Author(s):  
Is Fatimah ◽  
Putwi Widya Citradewi ◽  
Amri Yahya ◽  
Bambang Nugroho ◽  
Habibi Hidayat ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Antioxidant Activity ◽  
Particle Size ◽  
Gold Nanoparticles ◽  
Antibacterial Activity ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Dpph Scavenging Activity ◽  
Dpph Scavenging

Abstract The composite of green synthesized gold nanoparticles (Au NPs)-doped hydroxyapatite (HA) has been prepared. The gold nanoparticles were produced via bioreduction of HAuCl4 with Clitoria ternatea flower extract, and utilized in the synthesis of hydroxyapatite using Ca(OH)2 and ammonium diphosphate as precursor. The aim of this research is to study the structural analysis of the composite and antibacterial activity test toward Eschericia coli, Staphylococcus aureus, Klebsiela pneumoniae, and Streptococcus pyogenes. In addition, the antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging method. The monitoring of gold nanoparticles formation was conducted by UV–vis spectroscopy and particle size analyses, meanwhile the synthesized composite was studied using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The results showed that homogeneously dispersed gold nanoparticles in HA structure was obtained with the particle size ranging at 5-80 nm. The nanocomposite demonstrated antibacterial activity against tested bacteria. The nanocomposite expressed an antioxidant activity as shown by the DPPH scavenging activity of 66 and 58% at the concentration of 100 μg/mL and 50 μg/mL, respectively.

The mode of action of bacteriocin CHQS, a high antibacterial activity bacteriocin produced by Enterococcus faecalis TG2

Food Control ◽  
2019 ◽  
Vol 96 ◽  
pp. 470-478 ◽  
Author(s):  
Shuo Cao ◽  
Renpeng Du ◽  
Fangkun Zhao ◽  
Huazhi Xiao ◽  
Ye Han ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Enterococcus Faecalis ◽  
Mode Of Action ◽  
High Antibacterial Activity

scholarly journals Multifunctional Epoxy/Nanocomposites Based on Natural Moroccan Clays with High Antimicrobial Activity: Morphological, Thermal and Mechanical Properties

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
M. Monsif ◽  
A. Zerouale ◽  
N. Idrissi Kandri ◽  
R. Bertani ◽  
A. Bartolozzi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Antimicrobial Activity ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
Clay Nanocomposites ◽  
Mechanical And Thermal Properties ◽  
Clay Dispersion ◽  
Mechanical Stirring ◽  
Antimicrobial Materials ◽  
Transmission Electron

In this study, a series of new epoxy/clay nanocomposites (ECN) has been prepared and characterized in order to investigate the properties and compare the effect of the unmodified Moroccan clay on the structure and properties of the composite materials. Five natural clays have been used to reinforce the neat epoxy resin with 1% wt and 5% wt achieving the clay dispersion only through strong milling and mechanical stirring without previous organic modifications of the clays. The quality of clay dispersion in the epoxy matrix and the morphology of nanocomposites have been studied by transmission electron microscopy (TEM), environmental scanning electron microscopy (ESEM), and X-ray diffraction (XRD). The mechanical and thermal properties have also been investigated. The antimicrobial activity of the nanocomposites has been tested against E. coli and S. aureus in order to evaluate their applicability as advanced antimicrobial materials. The results showed that the epoxy/crude clay nanocomposites exhibited a high inhibition action attending 99% against both bacteria in the case of the clay labeled A5.

scholarly journals Ultrastructural Study of Elaeis guineensis (Oil Palm) Leaf and Antimicrobial Activity of its Methanol Extract against Staphylococcus Aureus

2016 ◽  
Vol 12 (3) ◽  
pp. 419-423 ◽  
Author(s):  
Amala Rajoo ◽  
Sreenivasan Sasidharan ◽  
Subramanion L Jothy ◽  
Surash Ramanathan ◽  
Sharif M Mansor
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Transmission Electron Microscopy ◽  
Antimicrobial Activity ◽  
Methanol Extract ◽  
Elaeis Guineensis ◽  
Transmission Electron ◽  
Inhibition Concentration ◽  
Scanning Electron

Purpose: To evaluate the antimicrobial activity of the methanol extract of Elaeis guineensis leaf against Staphylococcus aureus and to determine the effect of extract treatment on the microstructure of the microbeMethods: The antimicrobial activity of the methanol leaf extract of the plant against S. aureus was examined using disc diffusion and broth dilution methods. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were carried out to determine the major alterations in the microstructure of S. aureus after treatment with the extract.Results: The extract showed a good antimicrobial activity against S. aureus with a minimum inhibition concentration (MIC) of 6.25 mg/mL and for Chloramphenicol was 30.00 ìg/mL. The main changes observed under SEM and TEM were structural disorganization of the cell membrane which occurred after 12 h and total collapse of the cell 36 h after exposure to the extract.Conclusion: We concluded that the methanolic extract of E. guineensis leaf exhibited good antimicrobial activity against S. aureus and this is supported by SEM and TEM.Keywords: Antimicrobial activity, Elaeis guineensis, Staphylococcus aureus, Scanning electron microscopy, Transmission electron microscopy

Benzannulated Re(i)–NHC complexes: synthesis, photophysical properties and antimicrobial activity

2017 ◽  
Vol 46 (44) ◽  
pp. 15269-15279 ◽  
Author(s):  
Daniel Siegmund ◽  
Nicole Lorenz ◽  
Yvonne Gothe ◽  
Christian Spies ◽  
Bastian Geissler ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Photophysical Properties ◽  
High Antibacterial Activity ◽  
Strong Luminescence

A series of novel Re(i)(CO)3–NHC complexes bearing unsubstituted benzimidazol-2-ylidene ligands is presented which provide strong luminescence as well as high antibacterial activity.

Antimicrobial Activity of O-Carboxymethyl Chitosan Nanofibers Containing Silver Nanoparticles Synthesized by Green Method

2016 ◽  
Vol 40 ◽  
pp. 136-145 ◽  
Author(s):  
Metwally Ezzat ◽  
Mohammed Ghanim ◽  
Hassan Nageh ◽  
Ahmed H. Hassanin ◽  
Ahmed Abdel-Moneim
Keyword(s):  
Antibacterial Activity ◽  
Wound Dressing ◽  
Pathogenic Bacteria ◽  
Reaction Times ◽  
Carboxymethyl Chitosan ◽  
Diffusion Method ◽  
Ag Nps ◽  
High Antibacterial Activity ◽  
Transmission Electron ◽  
Bacteria And Fungi

New green synthesis of Ag-nanoparticles (Ag-NPs) using O-Carboxymethyl Chitosan (O-CMCs) as stabilizing agent and ascorbic acid as reducing agent was achieved. The reaction was carried out in an autoclave at a pressure of 0.12 MPa and a temperature of 120°C at varying concentrations of solution precursors and different reaction times. The size, shape and structure of Ag-NPs were measured using transmission electron microscope (TEM), X-Ray Diffraction (XRD), FT-IR and UV spectrophotometers. The Ag-NPs stabilized in O-CMCs were blended with polyvinyl alcohol (PVA) polymer solution and then electrospun to produce wound dressing nanofibers with high antibacterial activity. The morphological study of O-CMCs/ PVA/Ag-NPs nanofiber membranes was characterized using SEM. Finally, the release behavior of Ag-NPs from these nanofibers was examined and the antibacterial activity was measured against some skin pathogenic bacteria and fungi using the agar diffusion method. The newly developed membranes show a unique antibacterial activity against the tested strains and were presented as promising active wound dressing materials in medical applications.

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