scholarly journals Dose-Dependent Antimicrobial Activity of Silver Nanoparticles on Polycaprolactone Fibers against Gram-Positive and Gram-Negative Bacteria

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Erick Pazos-Ortiz ◽  
Jose Hafid Roque-Ruiz ◽  
Efrén Amador Hinojos-Márquez ◽  
Juan López-Esparza ◽  
Alejandro Donohué-Cornejo ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Metallic Nanoparticles ◽  
Antibacterial Properties ◽  
Electrospinning Process ◽  
Drug Resistant ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Dose Dependent

The adhesion ability and adaptability of bacteria, coupled with constant use of the same bactericides, have made the increase in the diversity of treatments against infections necessary. Nanotechnology has played an important role in the search for new ways to prevent and treat infections, including the use of metallic nanoparticles with antibacterial properties. In this study, we worked on the design of a composite of silver nanoparticles (AgNPS) embedded in poly-epsilon-caprolactone nanofibers and evaluated its antimicrobial properties against various Gram-positive and Gram-negative microorganisms associated with drug-resistant infections. Polycaprolactone-silver composites (PCL-AgNPs) were prepared in two steps. The first step consisted in the reduction in situ of Ag+ions using N,N-dimethylformamide (DMF) in tetrahydrofuran (THF) solution, and the second step involved the simple addition of polycaprolactone before electrospinning process. Antibacterial activity of PCL-AgNPs nanofibers againstE. coli,S. mutans,K. pneumoniae,S. aureus,P. aeruginosa, andB. subtiliswas evaluated. Results showed sensibility ofE. coli,K. pneumoniae,S. aureus, andP. aeruginosa, but not forB. subtilisandS. mutans. This antimicrobial activity of PCL-AgNPs showed significant positive correlations associated with the dose-dependent effect. The antibacterial property of the PCL/Ag nanofibers might have high potential medical applications in drug-resistant infections.

scholarly journals Synthesis of Plant-Mediated Silver Nanoparticles UsingDioscorea batatasRhizome Extract and Evaluation of Their Antimicrobial Activities

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
P. C. Nagajyothi ◽  
K. D. Lee
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Room Temperature ◽  
Antimicrobial Activities ◽  
Gram Positive ◽  
Gram Negative ◽  
Synthesis Of Nanoparticles ◽  
E Coli ◽  
Synthesize Silver Nanoparticles ◽  
Dioscorea Batatas

The eco-friendly synthesis of nanoparticles through various biological means helps to explore various plants for their ability to synthesize silver nanoparticles (AgNPs). Here we have synthesized AgNPs by using rhizome extract ofDioscorea batatasat as well as room temperature (). AgNPs were characterized under UV-vis spectrophotometer, SEM, FTIR, XRD, and EDX. The antimicrobial activity of AgNPs was evaluated on gram positive (B. substilisandS. aureus), gram negative (E. coli), and fungi (S. cerivisaeandC. albicans). At room temperature,S. cerivisaeandC. albicanswere found to be more susceptible to AgNPs than at .

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.

Biosynthesis of Silver Nanoparticles by Punica Granatum Peel Extract and their Biological Activity on different Pathogenic Bacteria

2021 ◽  
Vol 19 (9) ◽  
pp. 38-45
Author(s):  
Hussein H. Al-Turnachy ◽  
Fadhilk. alibraheemi ◽  
Ahmed Abd Alreda Madhloom ◽  
Zahraa Yosif Motaweq ◽  
Nibras Yahya Abdulla
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Biological Activity ◽  
Pathogenic Bacteria ◽  
Punica Granatum ◽  
Gram Positive ◽  
Gram Negative ◽  
Inhibition Zones ◽  
Peel Extract

The present study was included the assessment of the antimicrobial activity of AgNPs synthesized by Punica granatum peel extract against pathogenic bacteria by testing warm aqueous P. granatum peel extract and silver nanoparticles. Punica granatum indicated potency for AgNP extracellular nanobiosynthesis after addition of silver nitrate (AgNO3) 4mM to the extract supernatant, in both concentrations (100mg and 50mg). The biogenic AgNPs showed potency to inhibit both gram-negative and gram-positive bacterial growth. Zons of inhibition in (mm) was lesser in gram-positive than gram-negative bacteria. The resulted phytogenic AgNPs gave higher biological activity than warm aqueous Punica granatum peel extract. The inhibition zone of the phytogenic AgNPs on E. coli reached 17.53, 22.35, and 26.06 mm at (0.1, 0.5, and 1) mg/ml respectively. While inhibition zones of Punica warm aqueous extract reached 5.33, 10.63, and 16.08 mm at the same concentrations. phytogenic AgNPs gave smaller inhibition zones in gram-positive than gram- negative. Cytotoxic activity of the phytogenic AgNPs was assayed in vitro agaist human blood erythrocytes (RBCs), spectroscopic results showed absorbance at 540 nm hemolysis was observed. In general, AgNPs showed least RBCs hemolysis percentage, at 1 mg/ml concentration, hemolysis percentage was (4.50%). This study, concluded that the Punica granatum peel extract has the power of synthses of AgNPs characterized by broad spectrum antimicrobial activity with cyto-toxicity proportional to AgNPs concentration.

scholarly journals Anticancer and Antimicrobial Activity Evaluation of Cowpea-Porous-Starch-Formulated Silver Nanoparticles

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Shiara Ramdath ◽  
John Mellem ◽  
Londiwe Simphiwe Mbatha
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Cell Viability ◽  
High Dose ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Anticancer Drug Delivery ◽  
Ic50 Values ◽  
Biosynthesized Agnps

Health issues involving inadequate treatment of diseases such as cancer and microbial infections continue to be the subject of much ongoing recent research. Biosynthesized silver nanoparticles (AgNPs) were characterized using Transmission Electron Microscopy (TEM), Zeta Sizer, Ultraviolet (UV), and Fourier Transform Infrared (FTIR) spectroscopy. Their antimicrobial activity was evaluated on selected Gram-positive and Gram-negative bacterial strains, using the disc diffusion and broth dilution assays. Cell viability profiles were evaluated using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and apoptosis studies on selected human noncancer and cancer cells. The biosynthesized AgNPs were evaluated to be spherical clusters, with sizes between 40 and 70 nm. The absorption peak at 423 nm and the presence of polyphenols confirmed the synthesis and stabilization of these tested AgNPs. The AgNPs showed a good stability of −23.9 ± 1.02 mV. Good antimicrobial activity (6.0–18.0 mm) was seen on all tested bacteria at a minimum inhibitory concentration (MIC) ranging from 5 to 16 μg/ml, with the highest activity seen against Gram-negative Escherichia coli (18 ± 0.5 mm), and the lowest activity was seen against Gram-positive Listeria monocytogenes (6.0 ± 0.4 mm) after treatment with the AgNPs. These NPs showed a concentration-dependent and cell-specific cytotoxicity with low IC50 values (41.7, 56.3, and 63.8 μg/ml). The NPs were well tolerated by tested cells as indicated by a more than 50% cell viability at the high dose tested and low apoptotic indices (<0.2). These findings indicated that these biosynthesized AgNPs showed great potential as effective antibacterial agents and anticancer drug delivery modalities.

scholarly journals Antimicrobial Activity and HPLC Fingerprinting of CrudeOcimumExtracts

2011 ◽  
Vol 8 (3) ◽  
pp. 1430-1437 ◽  
Author(s):  
S. S. Deo ◽  
F. Inam ◽  
R. P. Mahashabde
Keyword(s):  
Antimicrobial Activity ◽  
Methanolic Extract ◽  
Ocimum Sanctum ◽  
Moderate Activity ◽  
Aqueous Extracts ◽  
Gram Positive ◽  
Strong Activity ◽  
Gram Negative ◽  
E Coli ◽  
Strong Antimicrobial Activity

The antimicrobial activity of crude methanolic and aqueous extracts ofOcimum sanctumandOcimum kilimandsacharicumagainst gram positive, gram negative and antifungal activity was evaluated to find the zone of inhibition and to set a HPLC profile or fingerprint of these extracts. The crude methanolic extract ofOcimum sanctumshowed strong antimicrobial activity againstS.aureusandC. albicansand moderate activity againstE. coliandB. subtilis. The crude methanolic extract ofOcimum kilimandsacharicumshowed strong antimicrobial activity againstS. aureus, E. coliandC. albicansat higher concentration, same as that shown by the standard forC. albicans. It showed moderate activity againstB. subtilis. The crude aqueous extracts of Ocimum sanctum showed strong antimicrobial activity againstS.aureusand moderate against others. Whereas the crude aqueous extracts ofOcimum kilimandsacharicumshowed moderate activity against the gram positive and gram negative organisms and strong activity againstC. albicansat higher concentration, same as that shown by the standard forC. albicans.

Effect of Ni and Zn Elements on the Microstructure and Antibacterial Properties of Cu Coatings

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Khaled S. Al-Athel ◽  
Najat Marraiki ◽  
Abul Fazal M. Arif ◽  
Syed Sohail Akhtar ◽  
Javad Mostaghimi ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Bacterial Adhesion ◽  
316L Stainless Steel ◽  
Coating Layer ◽  
Antibacterial Properties ◽  
Lower Surface ◽  
Distilled Water ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli

In this work, 316L stainless steel samples were coated with copper (Cu) and German silver (Cu 17%Ni 10%Zn) to investigate the relation between their mechanical and antibacterial behaviors. The mechanical and material characteristics of the samples were studied by looking into the microstructure of the surface and the cross-section of the coatings, the surface roughness, and the adhesion strength between the coating layer and the substrate. The antibacterial behavior is then studied against gram-negative Escherichia coli and gram-positive Staphylococcus aureus. Two experiments were conducted to examine the antibacterial behavior. In the first experiment, the coated samples were covered with distilled water, whereas in the second experiment, the samples were tested without being covered with distilled water. The results show that German silver (Cu 17%Ni 10%Zn) had a higher antibacterial rate than copper (Cu) by around 10% for both gram-negative E. coli and gram-positive S. aureus. The reason is because a smoother surface is expected to limit the bacterial adhesion in most cases, and the German silver samples have a lower surface roughness (Ra) due to the higher thermal expansion value of zinc (Zn) compared with copper (Cu). A more in-depth look into the effect of various thickness of the coating with alloying elements (in this case nickel and zinc) on the antibacterial rate would be of great interest.

SILVER NANOPARTICLE IMPREGNATED BIO-BASED ACTIVATED CARBON WITH ENHANCED ANTIMICROBIAL ACTIVITY

2013 ◽  
Vol 12 (04) ◽  
pp. 1350024 ◽  
Author(s):  
R. SELVAKUMAR ◽  
S. P. SURIYARAJ ◽  
V. JAYAVIGNESH ◽  
K. SWAMINATHAN
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Yeast Cells ◽  
X Ray Diffraction ◽  
Gram Positive ◽  
Biological Reduction ◽  
Gram Negative ◽  
Transmission Electron ◽  
Gram Negative Organisms ◽  
Average Size

The present study involves the production of silver nanoparticles using a novel yeast strain Saccharomyces cerevisiae BU-MBT CY-1 isolated from coconut cell sap. The biological reduction of silver nitrate by the isolate was deducted at various time intervals. The yeast cells after biological silver reduction were harvested and subjected to carbonization at 400°C for 1 h and its properties were analyzed using Fourier transform infra-red spectroscopy, X-ray diffraction, scanning electron microscope attached with energy dispersive spectroscopy and transmission electron microscopy. The average size of the silver nanoparticles present on the surface of the carbonized silver containing yeast cells (CSY) was 19 ± 9 nm. The carbonized control yeast cells (CCY) did not contain any particles on its surface. The carbonized silver nanoparticles containing yeast cells (CSY) were made into bioactive emulsion and tested for its efficacy against various pathogenic Gram positive and Gram negative bacteria. The antimicrobial activity studies indicated that CSY bioactive nanoemulsion was effective against Gram negative organisms than Gram positive organism.

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 Hybrid Approach for Synthesis and Antimicrobial Activity of Heterocyclic Compounds

2018 ◽  
Vol 77 ◽  
pp. 35-52 ◽  
Author(s):  
Nisheeth C. Desai ◽  
Darshita V. Vaja
Keyword(s):  
Antimicrobial Activity ◽  
Heterocyclic Compounds ◽  
Hybrid Approach ◽  
Spectroscopic Techniques ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Microbial Strains

We have synthesized novel series of N-(1-(2-(1-phenyl-3-(p-tolyl)-1H-pyrazol-4-yl)-5-(pyridin-4-yl)-1,3,4-oxadiazol-3(2H)-yl)ethylidene)arylaniline and their derivatives. The structures of synthesized compounds were well characterized by spectroscopic techniques. Antimicrobial activity of the newly synthesized derivatives was evaluated against gram positive (S. aureus and S. pyogenes), gram negative bacteria (E. coli and P. aeruginosa), and strains of fungi (C. albicans, A. niger and A. clavatus). Among the screened derivatives 5c, 5f, 5i, 5l and 5t demonstrated superior antimicrobial activity against microbial strains.

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.

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