scholarly journals Growth Kinetics and Mechanistic Action of Reactive Oxygen Species Released by Silver Nanoparticles fromAspergillus nigeronEscherichia coli

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Shivaraj Ninganagouda ◽  
Vandana Rathod ◽  
Dattu Singh ◽  
Jyoti Hiremath ◽  
Ashish Kumar Singh ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Growth Kinetics ◽  
Antibacterial Properties ◽  
Average Diameter ◽  
E Coli ◽  
Radical Generation ◽  
Bacterial Growth Inhibition ◽  
Kinetics Of ◽  
Silver Bullet

Silver Nanoparticles (AgNPs), the real silver bullet, are known to have good antibacterial properties against pathogenic microorganisms. In the present study AgNPs were prepared from extracellular filtrate ofAspergillus niger. Characterization of AgNPs by UV-Vis spectrum reveals specific surface plasmon resonance at peak 416 nm; TEM photographs revealed the size of the AgNPs to be 20–55 nm. Average diameter of the produced AgNPs was found to be 73 nm with a zeta potential that was −24 mV using Malvern Zetasizer. SEM micrographs showed AgNPs to be spherical with smooth morphology. EDS revealed the presence of pure metallic AgNPs along with carbon and oxygen signatures. Of the different concentrations (0, 2.5, 5, 10, and 15 μg/mL) used 10 μg/mL were sufficient to inhibit 107 CFU/mL ofE. coli. ROS production was measured using DCFH-DA method and the the free radical generation effect of AgNPs on bacterial growth inhibition was investigated by ESR spectroscopy. This paper not only deals with the damage inflicted on microorganisms by AgNPs but also induces cell death through the production of ROS released by AgNPs and also growth kinetics ofE. colisupplemented with AgNPs produced byA. niger.

scholarly journals Formation and Investigation of Electrospun PLA Materials with Propolis Extracts and Silver Nanoparticles for Biomedical Applications

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Erika Adomavičiūtė ◽  
Solveiga Pupkevičiūtė ◽  
Vaida Juškaitė ◽  
Modestas Žilius ◽  
Sigitas Stanys ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Release Kinetics ◽  
Antibacterial Properties ◽  
Ethanolic Extract ◽  
Average Diameter ◽  
Nonwoven Material ◽  
Water Soluble ◽  
Antimicrobial Protection ◽  
Kinetics Of

An electrospun hydrophilic non-water-soluble biocompatible polylactic acid (PLA) nonwoven material was used as a delivery system for propolis ethanolic extract (PEE) and silver nanoparticles (AgNPs) that are known for their established antiseptic and antimicrobial activity. Combination of PEE and AgNPs in a single product should provide efficient antimicrobial protection and improved wound healing. Evaluations of PEE and AgNPs on morphology of electrospun materials, release kinetics of AgNPs and phenolic compounds, antibacterial properties, and cytotoxicity of electrospun PLA materials were performed. The presence of PEE or/and AgNPs resulted in denser mats formed by thicker PLA fibers. The average diameter of PLA microfibers was 168±29 nm. The average diameter of microfibers increased to 318±40 and 370±30 nm when 10 wt% and 20 wt% ethanol were added, respectively. Addition of 10 wt% or 20 wt% PEE increased the diameter to 282±25 and 371±25 nm, respectively. Suspension of AgNPs also caused the formation of thicker microfibers with 254±25 nm diameter. Electrospun PLA microfibers with PEE maintained viability of HaCaT cells. Testing of antimicrobial activity confirmed the ability of AgNPs containing PLA electrospun materials to inhibit the growth of microorganisms.

Optimization and Characterization of Biogenic Silver Nanoparticles Synthesized by Leaves Extract of Alphonsea Madraspatana

2021 ◽  
Vol 17 ◽  
Author(s):  
Amita Sahu ◽  
Sudhanshu Shekhar Swain ◽  
Goutam Ghosh ◽  
Deepak Pradhan ◽  
Dipak Kumar Sahu ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Volume Ratio ◽  
Xrd Analysis ◽  
Biofilm Inhibition ◽  
Nano Silver ◽  
E Coli ◽  
Biogenic Silver Nanoparticles ◽  
Icp Ms ◽  
Anti Oxidant

Background: Literature evidences as well as traditional uses of genus Alphonsea reveal significant antimicrobial and anti-oxidant activity, which encourages to consider A. madraspatana to have potent antimicrobials, there by offering potential adjuncts to synthesize improved antimicrobial Silver nanoparticles (AgNPs). The objective of the present exposition is to optimize reaction parameters to synthesize antimicrobial Biogenic Silver nanoparticles (BAgNPs) from extract of A. madraspatana leaves (AML) and to evaluate the effect against bacteria. Methods: BAgNPs was synthesized by optimized reaction. The Synthesized nanoparticles were characterized by UV, IR, ICP-MS and XRD analysis. The antibacterial potency of optimized BAgNPs was evaluated against E. coli by comparing with positive controls. Results: Results of optimization process indicate nanoscale BAgNPs were produced at operating temp. of 45°C for 120 min at pH 8 with 1:5 volume ratio of AgNO3 and extract. Optimized BAgNPs exhibits relatively higher antimicrobial activity (31±1mm) compared to Ciprofloxacin (27±1mm) and marketed nano silver (28± 2 mm). The developed BAgNPs shows comparable biofilm inhibition (86.50%) as compared to marketed nano silver (88.10%) and Ciprofloxacin (83.10%). Conclusion: Experimental evidence suggests methanolic extract of AML under predefined conditions successfully generate nano-template of silver with better antibacterial response against E. coli.

scholarly journals Green ultrasonic synthesis, Characterization and Antibacterial activity of Silver and Gold Nanoparticles mediated by Ganoderma lucidum extract

2020 ◽  
Vol 4 (2) ◽  
Keyword(s):  
Gold Nanoparticles ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Metal Nanoparticles ◽  
Cytotoxic Activities ◽  
Gold And Silver Nanoparticles ◽  
Silver And Gold Nanoparticles ◽  
E Coli ◽  
Inhibition Zones

Metal nanoparticles possess an extensive scientific and technological significance due to their unique physiochemical properties and their potential applications in different fields like medicine. Silver and gold nanoparticles have shown to have antibacterial and cytotoxic activities. Conventional methods used in the synthesis of the metal nanoparticles involve use of toxic chemicals making them unsuitable for use in medical field. In our continued effort to explore for simple and eco-friendly methods to synthesize the metal nanoparticles, we here describe synthesis and characterization of gold and silver nanoparticles using Gonaderma lucidum, wild non-edible medicinal mushroom. G. lucidum mushroom contain bioactive compounds which can be involved in the reduction, capping and stabilization of the nanoparticles. Antibacterial activity analysis was done on E. coli and S. aureus. The synthesis was done on ultrasonic bath. Characterization of the metal nanoparticles was done by UV-VIS., High Resolution Transmission Electron Microscope (HRTEM) and FTIR. HRTEM analysis showed that both silver and gold nanoparticles were spherical in shape with an average size of 15.82±3.69 nm for silver and 24.73±5.124nm for gold nanoparticles (AuNPs). FTIR analysis showed OH and -C=C- stretching vibrations, an indication of presence of functional groups of biomolecules capping both gold and silver nanoparticles. AgNPs showed inhibition zones of 15.5±0.09mm and 13.3±0.14mm while AuNPs had inhibition zones of 14.510±0.35 and 13.3±0.50mm on E. coli and S. aureus respectively. The findings indicate the potential use of AgNPs and AuNPs in development of drugs in management of pathogenic bacteria.

scholarly journals Functional and structural basis of E. coli enolase inhibition by SF2312: a mimic of the carbanion intermediate

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jolanta Krucinska ◽  
Michael N. Lombardo ◽  
Heidi Erlandsen ◽  
Akram Hazeen ◽  
Searle S. Duay ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Antibacterial Properties ◽  
High Energy ◽  
Structural Basis ◽  
Gram Negative Bacteria ◽  
E Coli ◽  
Promising Target ◽  
Antibiotic Discovery ◽  
Growth And Reproduction

AbstractMany years ago, the natural secondary metabolite SF2312, produced by the actinomycete Micromonospora, was reported to display broad spectrum antibacterial properties against both Gram-positive and Gram-negative bacteria. Recent studies have revealed that SF2312, a natural phosphonic acid, functions as a potent inhibitor of human enolase. The mechanism of SF2312 inhibition of bacterial enolase and its role in bacterial growth and reproduction, however, have remained elusive. In this work, we detail a structural analysis of E. coli enolase bound to both SF2312 and its oxidized imide-form. Our studies support a model in which SF2312 acts as an analog of a high energy intermediate formed during the catalytic process. Biochemical, biophysical, computational and kinetic characterization of these compounds confirm that altering features characteristic of a putative carbanion (enolate) intermediate significantly reduces the potency of enzyme inhibition. When SF2312 is combined with fosfomycin in the presence of glucose-6 phosphate, significant synergy is observed. This suggests the two agents could be used as a potent combination, targeting distinct cellular mechanism for the treatment of bacterial infections. Together, our studies rationalize the structure-activity relationships for these phosphonates and validate enolase as a promising target for antibiotic discovery.

Time resolved growth of membrane stabilized silver NPs and their catalytic activity

RSC Advances ◽  
2014 ◽  
Vol 4 (103) ◽  
pp. 59379-59386 ◽  
Author(s):  
Sabyasachi Patra ◽  
Debasis Sen ◽  
Ashok K. Pandey ◽  
J. Bahadur ◽  
S. Mazumder ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Catalytic Activity ◽  
Growth Kinetics ◽  
Nanocomposite Membranes ◽  
Time Resolved ◽  
Catalytic Application ◽  
Silver Nps ◽  
First Time ◽  
Kinetics Of

Growth kinetics of membrane stabilized silver nanoparticles have been studied for the first time with time resolved in situ SAXS. The catalytic application of nanocomposite membranes thus formed has also been explored.

scholarly journals Antibacterial Activity and Iron Release of Organic-Inorganic Hybrid Biomaterials Synthesized via the Sol-Gel Route

2021 ◽  
Vol 11 (19) ◽  
pp. 9311
Author(s):  
Michelina Catauro ◽  
Ylenia D’Errico ◽  
Antonio D’Angelo ◽  
Ronald J. Clarke ◽  
Ignazio Blanco
Keyword(s):  
Hybrid Materials ◽  
Release Kinetics ◽  
Sol Gel ◽  
Antibacterial Properties ◽  
Iron Release ◽  
Biological Characterization ◽  
Visible Spectroscopy ◽  
E Coli ◽  
Hybrid Biomaterials ◽  
Kinetics Of

The aim of this work was the synthesis of hybrid materials of iron (II)-based therapeutic systems via the sol-gel method. Increasing amounts of polyethylene glycol (PEG 6, 12, 24, 50 wt%) were added to SiO2/Fe20 wt% to modulate the release kinetics of the drug from the systems. Fourier-transform infrared (FTIR) spectroscopy was used to study the interactions between different components in the hybrid materials. The release kinetics in a simulated body fluid (SBF) were investigated, and the amount of Fe2+ released was detected via ultraviolet-visible spectroscopy (UV-Vis) after reaction with ortho-phenanthroline. Furthermore, biological characterization was carried out. The bioactivity of the synthesized hybrid materials was evaluated via the formation of a layer of hydroxyapatite on the surface of samples soaked in SBF using spectroscopy. Finally, the potential antibacterial properties of seven different materials against two different bacteria—E. coli and S. aureus—were investigated.

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