scholarly journals Preparation of Antimicrobial Fibres from the EVOH/EPC Blend Containing Silver Nanoparticles

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1827
Author(s):  
Dorota Biniaś ◽  
Włodzimierz Biniaś ◽  
Alicja Machnicka ◽  
Monika Hanus
Keyword(s):  
Staphylococcus Aureus ◽  
Silver Nanoparticles ◽  
Sodium Stearate ◽  
Morphological Structure ◽  
Silver Particles ◽  
Gram Positive ◽  
Ethylene Vinyl Alcohol ◽  
Agno3 Solution ◽  
Elemental Silver ◽  
Developed Surface

The article presents a new fabrication method for bioactive fibres with a microporous structure of ethylene–vinyl alcohol copolymers (EVOH)/ethylene−propylene copolymer (EPC) blends. The experimental work carried out resulted in obtaining EVOH/EPC polymer blends fibres with the addition of glycerol and sodium stearate. Different concentrations of glycerol (38%, 32%) and sodium stearate (2%, 8%) were used to prepare the fibres. The purpose of using different concentrations of stearate and glycerol was to evaluate the effect of additives on the structure and properties of the fibres. A significant influence of the additives used on the morphological structure of the fibres was found. The resulting fibres were modified with an AgNO3 solution and reduced to silver nanoparticles (AgNPs), to give the fibres bioactive properties. The fibres obtained with the addition of 8% stearate have a more developed surface, which may influence the amount of adsorbed silver particles inside the fibre. However, the durability of depositing silver particles after multiple washes has not been tested. Three types of microorganisms were selected to assess the microbiological activity of the obtained fibres, i.e., Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa and Escherichia coli. The fibres have antibacterial activity against gram positive and negative bacteria. The largest inhibition zones were obtained for gram-positive bacteria Staphylococcus aureus, ranging from 3 to 10 mm depending on the concentration of AgNPs. The morphology of the blends fibres was characterized by scanning electron microscopy (SEM) and optical microscopy (OM). The occurrence of elemental silver was analysed by energy dispersive spectroscopy (EDS) analysis. The changes of the polymer structure chemistry are studied by Fourier transform infrared spectroscopy (FTIR).

scholarly journals Green synthesis of silver nanoparticles using aqueous extract of Citrus sinensis peels and evaluation of their antibacterial efficacy

2021 ◽  
Vol 10 (1) ◽  
pp. 851-859
Author(s):  
Lebogang Mogole ◽  
Wesley Omwoyo ◽  
Elvera Viljoen ◽  
Makwena Moloto
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Citrus Sinensis ◽  
Antimicrobial Activities ◽  
Antibacterial Efficacy ◽  
Gram Positive ◽  
Gram Negative ◽  
Average Size ◽  
Passivating Agent

Abstract The resistance of microorganisms towards antibiotics remains a big challenge in medicine. Silver nanoparticles (AgNPs) received attention recently for their characteristic nanosized features and their ability to display antimicrobial activities. This work reports the synthesis of AgNPs using the Citrus sinensis peels extract in their aqueous, mild, and less hazardous conditions. The effect of concentration variation (1%, 2%, and 3%) of the plant extracts on the size and shape of the AgNPs was investigated. The antimicrobial activities were tested against gram-positive Staphylococcus aureus and gram-negative Klebsiella pneumoniae. Absorption spectra confirmed the synthesis by the surface Plasmon resonance peaks in the range 400–450 nm for all the AgNPs. FTIR spectra confirmed that Citrus sinensis peels extract acted as both reducing and surface passivating agent for the synthesized AgNPs. TEM revealed spherical AgNPs with average size of 12 nm for 3% concentration as compared to the agglomeration at 1% and 2%. All the AgNPs synthesized using Citrus sinensis peels extracts (1%, 2%, and 3%) exhibited antimicrobial activity against both gram-positive and negative bacteria. These results indicated a simple, fast, and inexpensive synthesis of silver nanoparticles using the Citrus sinensis peels extract that has promising antibacterial activity.

scholarly journals Preparation of Polypropylene/silver nanoparticles Nanocomposite films and Evaluation of its Barrier and Antimicrobial Properties for Packaging Applications

2021 ◽  
Vol 9 (VIII) ◽  
pp. 764-774
Author(s):  
Rajesh Kumar Sahoo
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Silver Nanoparticles ◽  
Transmission Rate ◽  
Polymeric Films ◽  
Nanocomposite Films ◽  
Polypropylene Film ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Water Vapour Transmission Rate

Polymeric films which can be used in packaging industries were prepared by blown film method with polypropylene chips and silver nanoparticles. The nanocomposite films were characterized concerning its potential use. Oxygen Transmission rate (OTR) measurements was done in order to ascertain permeability of oxygen through the polymeric films. It was found that the permeability of oxygen through nanocomposite film is higher than that of virgin polypropylene film due to incompatibility between polypropylene matrix and silver nanoparticles. The water vapour transmission rate (WVTR) test of the polymeric nanocomposite films was calculated in order to know the information about mass transfer mechanisms and solute-polymer interactions in the food packaging film. It has been found that, there is a significant decreased water vapour transmission rate through nanocomposite films compared to that of virgin polypropylene film. With increasing the concentration of silver nanoparticles, this effect was reduced. The explanation for this could be that with higher concentration of silver nanoparticles agglomeration in the polymer film could the possibility which create narrow pathway for water molecules to travel. The effect of various silver nanoparticles content in the polymer nanocomposites with respect to its antimicrobial efficacy against the Gram positive bacteria Escherichia coli and Gram positive bacteria Staphylococcus aureus were studied. However, Escherichia coli was most effectively retarded by silver nanoparticles than Staphylococcus aureus, which is related to the difference in the cell wall of the gram positive and gram negative bacteria.

scholarly journals Plasmon Resonance of Silver Nanoparticles as a Method of Increasing Their Antibacterial Action

Antibiotics ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 80 ◽  
Author(s):  
Alexander Vasil’kov ◽  
Ruslan Dovnar ◽  
Siarhei Smotryn ◽  
Nikolai Iaskevich ◽  
Alexander Naumkin
Keyword(s):  
Staphylococcus Aureus ◽  
Silver Nanoparticles ◽  
Plasmon Resonance ◽  
Photoelectron Spectroscopy ◽  
Antibacterial Properties ◽  
Petri Dish ◽  
Aureus Strain ◽  
Gram Positive ◽  
Gram Negative ◽  
X Ray

In this article, a series of silver-containing dressings are prepared by metal-vapor synthesis (MVS), and their antibacterial properties are investigated. The antibacterial activity of the dressings containing silver nanoparticles (AgNPs) against some Gram-positive, and Gram-negative microorganisms (Staphylococcus aureus, Staphylococcus haemolyticus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Moraxella spp.) has been determined. Based on the plasmon resonance frequency of these nanoparticles, the frequency of laser irradiation of the dressing was chosen. The gauze bandage examined showed pronounced antibacterial properties, especially to Staphylococcus aureus strain. When 470 nm laser radiation, with a power of 5 mW, was applied for 5 min, 4 h after inoculating the Petri dish, and placing a bandage containing silver nanoparticles on it, the antibacterial effect of the latter significantly increased—both against Gram-positive and Gram-negative microorganisms. The structure and chemical composition of the silver-containing nanocomposite were studied by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and extended X-ray absorption fine structure (EXAFS). The synthesized AgNPs demonstrate narrow and monomodal particle size distribution with an average size of 1.75 nm. Atoms of metal in Ag/bandage system are mainly in Ag0 state, and the oxidized atoms are in the form of Ag-Ag-O groups.

scholarly journals Preparation of Silver Nanoparticles Suitable for Textile Finishing Processes to Produce Textiles with Strong Antibacterial Properties against Different Bacteria Types

2011 ◽  
Vol 66 (9) ◽  
pp. 905-916 ◽  
Author(s):  
Boris Mahltig ◽  
Marianne Reibold ◽  
Emanuel Gutmann ◽  
Torsten Textor ◽  
Jochen Gutmann ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Antibacterial Properties ◽  
Preparation Technique ◽  
Silver Particles ◽  
High Antimicrobial Activity ◽  
Elemental Silver ◽  
Vis Spectroscopy ◽  
Potential Applications ◽  
Coating Agents

This study describes the development of a preparation technique for silver nanoparticles useable as antimicrobial material which is especially useful for textile treatment to realize antimicrobial fabrics. The silver particles need to be prepared by reduction of AgNO3 under moderate conditions and with a moderate and non-toxic reductive agent. Comparative investigations were carried out with silver particles prepared by a solvothermal process or with NaBH4 as reductive agent. Particularly, suitable silver solutions are obtained by stabilizing the silver particles with polyvinylpyrollidone PVP of high molecular weight (Mw ~ 360000 gmol−1) and the use of the non-toxic reductive agents ascorbic acid and fructose. Under these conditions the diameters of the silver particles are in the range of 10 to 30 nm as determined by HR-TEM. The formation of elemental silver has been verified by transmission electron microscopy (TEM), X-ray diffraction (XRD) and optical spectroscopy. The properties of silver particle-containing liquids were investigated by using UV/Vis spectroscopy and dynamic light scattering. Further information on particle size and size distribution was gained through SEM investigations. The prepared solutions of silver nanoparticles can be applied easily onto textiles as liquid coating agents. All prepared textile samples exhibited a high antimicrobial activity against Escherichia coli. However, only few solutions containing silver particles of smaller size exhibit high antimicrobial activity also against other types of bacteria such as Staphylococcus aureus and Streptococcus pneumoniae. Because of this high antimicrobial potential gained with silver solutions prepared in a simple process without usage of toxic components, the developed materials offer a broad range of potential applications.

scholarly journals Formation of Nanoscale Elemental Silver Particles via Enzymatic Reduction by Geobacter sulfurreducens

2008 ◽  
Vol 74 (22) ◽  
pp. 7090-7093 ◽  
Author(s):  
Nicholas Law ◽  
Saadia Ansari ◽  
Francis R. Livens ◽  
Joanna C. Renshaw ◽  
Jonathan R. Lloyd
Keyword(s):  
Silver Nanoparticles ◽  
Geobacter Sulfurreducens ◽  
Contaminated Water ◽  
Silver Particles ◽  
Elemental Silver ◽  
Enzymatic Reduction

ABSTRACT Geobacter sulfurreducens reduced Ag(I) (as insoluble AgCl or Ag+ ions), via a mechanism involving c-type cytochromes, precipitating extracellular nanoscale Ag(0). These results extend the range of metals known to be reduced by Geobacter species and offer a method for recovering silver from contaminated water as potentially useful silver nanoparticles.

The effects of lasers and nanoparticles to kill and inactivate bacteria

2018 ◽  
Vol 9 (SPL1) ◽  
Author(s):  
Huda K Mohsen ◽  
Sadiq H Lafta ◽  
Qaiser N Mathlum
Keyword(s):  
Staphylococcus Aureus ◽  
Silver Nanoparticles ◽  
Diode Laser ◽  
Modern Method ◽  
Biological Science ◽  
Absorption Property ◽  
Gram Positive ◽  
Gold And Silver Nanoparticles ◽  
Gram Positive Bacteria ◽  
Conventional Antibiotics

The laser and nano-biological technical, representing the concourse biological science and nanotechnology,is considered modern method used as an anti-bacterial instead of conventional antibiotics. The present study is an attempt to illustrate how the use of lasers and silver nanoparticles each of them individually, as an anti-bacterial against the Staphylococcus aureus which gram positive bacteria. Bacteria (S. aureus) are irradiating by Nd: YVO4 and Diode laser with different powers and wavelengths,gold and silver nanoparticles it has been employed in the killing and inhibition of bacteria,by the effect of nanoparticles on its own,as well as using the absorption property of these nanoparticles for laser and subsequent mechanism this feature interact with bacteria.

Antibacterial and Cytotoxic Effects of Silver Nanoparticles on Staphylococcus aureus and Normal Vero Cells

2019 ◽  
Vol 22 (10) ◽  
pp. 184-190
Author(s):  
Rasha Hadi Saleh ◽  
Entisar J. Al-Mukhtar ◽  
Zaytoon A. Al-Khafaji ◽  
Mohammed H. Al Hasnawy ◽  
Huda H. Al-Hasnawy
Keyword(s):  
Staphylococcus Aureus ◽  
Silver Nanoparticles ◽  
Vero Cells ◽  
Cytotoxic Effects

Green and Simple Synthesis of Silver Nanoparticles by Aqueous Extract of Perovskia abrotanoides: Characterization, Optimization and Antimicrobial Activity

2020 ◽  
Vol 21 (11) ◽  
pp. 1129-1137 ◽  
Author(s):  
Somayeh Mirsadeghi ◽  
Masoumeh F. Koudehi ◽  
Hamid R. Rajabi ◽  
Seied M. Pourmortazavi
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Minimum Inhibitory Concentration ◽  
Plant Extract ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Extraction Temperature ◽  
Silver Particles ◽  
Silver Nps ◽  
Perovskia Abrotanoides

Background: Herein, we report the biosynthesis procedure to prepare silver nanoparticles as reduction and capping agents with the aqueous plant extract of Perovskia abrotanoides. Methods: The therapeutic application of silver nanoparticles entirely depends on the size and shape of the nanoparticles therefore, their control during the synthesis procedure is so important. The effects of synthesis factors, for example, silver ion concentration, the mass of plant extract, reaction time and extraction temperature, on the size of silver particles were considered and optimized. Several analytical methods were used for the characterization of silver NPs including FT-IR and UV–Vis spectrophotometer, XRD and SEM. Results: The results showed that the mean size of the silver particles was about 51 nm. Moreover, the antibacterial properties of biosynthesized silver NPs were investigated by the minimum inhibitory concentration, minimum bactericidal concentration, and Well-diffusion tests. The minimum inhibitory concentration/ minimum bactericidal concentration values of silver NPs and aqueous plant extract versus Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) and Gram-negative bacteria (E. coli) were 3.03/0.00, 1.20/0.01, 3.06/0.00, 0.98/1.04, 1.00/0.05 and 1.30/0.03 (mg/mL), respectively. Conclusion: The antimicrobial activity study displayed that the synthesized silver nanoparticles by plant extract have better antimicrobial properties compared to aqueous plant extract of Perovskia abrotanoides.

Green synthesised silver nanoparticles incorporated electrospun poly(methyl methacrylate) nanofibers with different architectures for ophthalmologic alternatives

2021 ◽  
Vol 36 (2) ◽  
pp. 93-110
Author(s):  
Princy Philip ◽  
Tomlal Jose ◽  
Sarath KS ◽  
Sunny Kuriakose
Keyword(s):  
Silver Nanoparticles ◽  
Methyl Methacrylate ◽  
Antibacterial Properties ◽  
Analytical Techniques ◽  
Morphological Properties ◽  
Gram Positive ◽  
Gram Negative ◽  
Poly Methyl Methacrylate ◽  
Antimicrobial Studies ◽  
Eye Problems

Silver nanoparticles with 5–10 nm diameters are synthesised using Couroupita guianensis flower extract. The synthesised silver nanoparticles found to show good antimicrobial activity against gram negative and gram positive bacteria. Poly(methyl methacrylate) nanofibers with pristine, surface roughened and coaxial hollow forms are prepared by electrospinning. The structural and morphological properties of these pure and structurally modified poly(methyl methacrylate) nanofibers are evidenced by various analytical techniques. The antimicrobial studies of poly(methyl methacrylate) nanofibers having different architectures incorporated with silver nanoparticles are carried out. It is found that, all the three forms of poly(methyl methacrylate) nanofibers incorporated with silver nanoparticles show antibacterial properties against both gram positive and gram negative bacteria. Among these, surface roughened poly(methyl methacrylate) nanofibers incorporated with silver nanoparticles show highest antibacterial activity than the other two structural forms. The present study offers an alternative to the existing optical lenses. People especially those who suffer from eye problems can protect their eyes in a better way from infectious agents by wearing optical lens made from C. guianensis stabilised silver nanoparticles incorporated poly(methyl methacrylate) nanofibers than that made from pure poly(methyl methacrylate) nanofibers or films.

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