scholarly journals Bactericidal Silver Nanoparticles by Atmospheric Pressure Solution Plasma Processing

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 874 ◽  
Author(s):  
Janith Weerasinghe ◽  
Wenshao Li ◽  
Rusen Zhou ◽  
Renwu Zhou ◽  
Alexander Gissibl ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Atmospheric Pressure ◽  
Chemical Reduction ◽  
Cost Effective ◽  
Pressure Solution ◽  
Gram Negative Bacteria ◽  
Promising Alternative ◽  
Gram Negative ◽  
Transmission Electron ◽  
Solution Plasma Processing

Silver nanoparticles have applications in plasmonics, medicine, catalysis and electronics. We report a simple, cost-effective, facile and reproducible technique to synthesise silver nanoparticles via plasma-induced non-equilibrium liquid chemistry with the absence of a chemical reducing agent. Silver nanoparticles with tuneable sizes from 5.4 to 17.8 nm are synthesised and characterised using Transmission Electron Microscopy (TEM) and other analytic techniques. A mechanism for silver nanoparticle formation is also proposed. The antibacterial activity of the silver nanoparticles was investigated with gram-positive and gram-negative bacteria. The inhibition of both bacteria types was observed. This is a promising alternative method for the instant synthesis of silver nanoparticles, instead of the conventional chemical reduction route, for numerous applications.

Antibacterial Potential of Silver Nanoparticles Capped with Poly(4-styrenesulfonic acid-co-maleic acid) Polymer

2015 ◽  
Vol 1088 ◽  
pp. 64-68 ◽  
Author(s):  
Hathaichanok Tamiyakul ◽  
Somboon Tanasupawat ◽  
Stephan Thierry Dubas ◽  
Warangkana Warisnoicharoen
Keyword(s):  
Staphylococcus Aureus ◽  
Silver Nanoparticles ◽  
Maleic Acid ◽  
Chemical Reduction ◽  
Spherical Particles ◽  
Metallic Silver ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
Gram Negative ◽  
Antibacterial Potential

Antibacterial potential of metallic silver nanoparticles (AgNPs) is considered to be influenced by their size and stability. In this study, the stable AgNPs capped with poly (4-styrenesulfonic acid-co-maleic acid) or PSSMA were successfully synthesized by using a chemical reduction method. The PSSMA-stabilized AgNPs (PSSMA-AgNPs) were characterized and tested for antibacterial activity against eight bacterial strains. Transmission electron microscopic studies showed that PSSMA-AgNPs were monodisperse spherical particles with an average size of 5.21 nm. From bacterial growth curve studies, PSSMA-AgNPs exhibited an antibacterial effect on Gram-positive bacteria (Staphylococcus aureus ATCC 25923, Staphylococcus aureus ATCC 6538p, Staphylococcus aureus ATCC 43300, Staphylococcus epidermidis ATCC 12228 and Bacillus subtilis ATCC 6633) and Gram-negative bacteria (Escherichia coli ATCC 25922, Enterobacter aerogenes ATCC 13048 and Pseudomonas aeruginosa ATCC 27853). Moreover, the Gram-negative bacteria were found to be more susceptible to the AgNPs.

Quality Improvement of the DNA extracted by boiling method in Gram negative bacteria

2017 ◽  
Vol 6 (04) ◽  
pp. 5347 ◽  
Author(s):  
Omar B. Ahmed* ◽  
Anas S. Dablool
Keyword(s):  
Dna Extraction ◽  
Control Method ◽  
Extraction Procedure ◽  
Cost Effective ◽  
High Yield ◽  
Gram Negative Bacteria ◽  
Bacterial Dna ◽  
Gram Negative ◽  
E Coli

Several methods of Deoxyribonucleic acid (DNA) extraction have been applied to extract bacterial DNA. The amount and the quality of the DNA obtained for each one of those methods are variable. The study aimed to evaluate bacterial DNA extraction using conventional boiling method followed by alcohol precipitation. DNA extraction from Gram negative bacilli was extracted and precipitated using boiling method with further precipitation by ethanol. The extraction procedure performed using the boiling method resulted in high DNA yields for both E. coli and K. pneumoniae bacteria in (199.7 and 285.7μg/ml, respectively) which was close to control method (229.3 and 440.3μg/ml). It was concluded that after alcohol precipitation boiling procedure was easy, cost-effective, and applicable for high-yield quality of DNA in Gram-negative bacteria.

Newer Quinolones in the Treatment of Continuous Ambulatory Peritoneal Dialysis (CAPD) Related Infections

1990 ◽  
Vol 10 (2) ◽  
pp. 127-133 ◽  
Author(s):  
Paul Nikolaidis
Keyword(s):  
Peritoneal Dialysis ◽  
Continuous Ambulatory Peritoneal Dialysis ◽  
Adverse Reactions ◽  
Antimicrobial Agents ◽  
Hospital Staff ◽  
Gram Negative Bacteria ◽  
Promising Alternative ◽  
Gram Negative ◽  
Dosing Intervals ◽  
Good Oral Bioavailability

Newer fluoroquinolones such as ciprofloxacin, pefloxacin, ofloxacin, enoxacin, and fleroxacin are potent antimicrobial agents against many gram-negative bacteria, including Pseudomonas aeruginosa species and staphylococci-sensitive or resistant to methicillin. They are almost completely absorbed when given orally, reaching therapeutic plasma and dialysate concentrations, and their long half lives permit infrequent dosing intervals. Clinical studies on fluoroquinolones efficacy in continuous ambulatory peritoneal dialysis (CAPD) infections, although not extensive, demonstrate good results. They are well tolerated and the adverse reactions, consisting mainly of gastrointestinal disturbance, were uncommon, mild, and reversible. The fluoroquinolones offer a promising alternative to standard parenteral treatments in CAPD patients, while their good oral bioavailability makes them attractive and convenient for both patients and hospital staff. However, they must be used with caution until we have more information and gain further experience.

scholarly journals Size Control of Synthesized Silver Nanoparticles by Simultaneous Chemical Reduction and Laser Fragmentation in Origanum majorana Extract: Antibacterial Application

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2326
Author(s):  
Entesar Ali Ganash ◽  
Reem Mohammad Altuwirqi
Keyword(s):  
Silver Nanoparticles ◽  
Irradiation Time ◽  
Chemical Reduction ◽  
Size Control ◽  
Reduction Process ◽  
Laser Wavelength ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
Transmission Electron ◽  
Origanum Majorana

In this work, silver nanoparticles (Ag NPs) were synthesized using a chemical reduction approach and a pulsed laser fragmentation in liquid (PLFL) technique, simultaneously. A laser wavelength of 532 nm was focused on the as produced Ag NPs, suspended in an Origanum majorana extract solution, with the aim of controlling their size. The effect of liquid medium concentration and irradiation time on the properties of the fabricated NPs was studied. While the X-ray diffraction (XRD) pattern confirmed the existence of Ag NPs, the UV–Vis spectrophotometry showed a significant absorption peak at about 420 nm, which is attributed to the characteristic surface plasmon resonance (SPR) peak of the obtained Ag NPs. By increasing the irradiation time and the Origanum majora extract concentration, the SPR peak shifted toward a shorter wavelength. This shift indicates a reduction in the NPs’ size. The effect of PLFL on size reduction was clearly revealed from the transmission electron microscopy images. The PLFL technique, depending on experimental parameters, reduced the size of the obtained Ag NPs to less than 10 nm. The mean zeta potential of the fabricated Ag NPs was found to be greater than −30 mV, signifying their stability. The Ag NPs were also found to effectively inhibit bacterial activity. The PLFL technique has proved to be a powerful method for controlling the size of NPs when it is simultaneously associated with a chemical reduction process.

A novel electrochemical comparative sensing interface of MgO nanoparticles synthesized by different methods

2017 ◽  
Vol 233 (3) ◽  
pp. 753-762 ◽  
Author(s):  
Utkarsh Jain ◽  
CS Pundir ◽  
Shaivya Gupta ◽  
Nidhi Chauhan
Keyword(s):  
Electrochemical Impedance ◽  
Chemical Reduction ◽  
Cost Effective ◽  
Green Technology ◽  
Mgo Nanoparticles ◽  
Transmission Electron ◽  
Impedance Spectroscopy Study ◽  
Vis Spectroscopy ◽  
Reduction Methods ◽  
Average Size

Recent advancements in nanotechnology, for the biosynthesis of metal nanoparticles through enormous techniques, showed multidimensional developments. One among many facets of nanotechnology is to procure and adopt new advancements for green technology over chemical reduction synthesis. This adaptation for acquiring green nanotechnology leads us to a new dimension of nanobiotechnology. In order to imply one such efforts, in this study the emphasis is being laid on the synthesis of MgO nanoparticles using green technology and eliminating chemical reduction methods. Different characterization techniques such as UV–Vis spectroscopy, transmission electron microscopy, and dynamic light scattering were used to carry out the experiments. The average size of MgO nanoparticles were obtained in the range of 85–95 nm, when synthesized by various sources. The extracts of plants were capable of producing MgO nanoparticles efficiently and exhibited good results during cyclic voltammetry and electrochemical impedance spectroscopy study. The electrode modified with MgO nanoparticles (plant extract) showed good stability (90 days) and high conductivity. This study reports cost-effective and environment-friendly method for synthesis of MgO nanoparticles using plant extracts. The process is rapid, simple, and convenient and can be used as an alternative to chemical method.

scholarly journals Biogenic Silver Nanoparticles Conjugated with Nisin: Improving the Antimicrobial and Antibiofilm Properties of Nanomaterials

Chemistry ◽  
2021 ◽  
Vol 3 (4) ◽  
pp. 1271-1285
Author(s):  
Patricia Zimet ◽  
Ruby Valadez ◽  
Sofía Raffaelli ◽  
María Belén Estevez ◽  
Helena Pardo ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antimicrobial Properties ◽  
Value Added ◽  
Green Technology ◽  
Natural Food ◽  
Antibiofilm Activity ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Biogenic Silver Nanoparticles

Microbial technology offers a green alternative for the synthesis of value-added nanomaterials. In particular, fungal compounds can improve silver nanoparticle production, stabilizing colloidal nanoparticles. Based on a previous study by our group, silver nanoparticles obtained using the extracellular cell-free extracts of Phanerochaete chrysosporium (PchNPs) have shown antimicrobial and antibiofilm activity against Gram-negative bacteria. Moreover, nisin—a bacteriocin widely used as a natural food preservative—has recently gained much attention due its antimicrobial action against Gram-positive bacteria in biomedical applications. Therefore, the aim of this work was to conjugate biogenic silver nanoparticles (PchNPs) with nisin to obtain nanoconjugates (PchNPs@nis) with enhanced antimicrobial properties. Characterization assays were conducted to determine physicochemical properties of PchNPs@nis, and also their antibacterial and antibiofilm activities were studied. The formation of PchNPs@nis was confirmed by UV-Vis, TEM, and Raman spectroscopy analysis. Different PchNPs@nis nanobioconjugates showed diameter values in the range of 60–130 nm by DLS and surface charge values between −20 and −13 mV. Nisin showed an excellent affinity to PchNPs, with binding efficiencies higher than 75%. Stable synthesized PchNPs@nis nanobioconjugates were not only able to inhibit biofilm formation by S. aureus, but also showed inhibition of the planktonic cell growth of Staphyloccocus aureus and Escherichia coli, broadening the spectrum of action of the unconjugated antimicrobials against Gram-positive and Gram-negative bacteria. In conclusion, these results show the promising application of PchNPs@nis, prepared via green technology, as potential antimicrobial nanomaterials.

scholarly journals Reversion of antibiotic resistance in multidrug-resistant pathogens using non-antibiotic pharmaceutical benzydamine

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yuan Liu ◽  
Ziwen Tong ◽  
Jingru Shi ◽  
Yuqian Jia ◽  
Tian Deng ◽  
...  
Keyword(s):  
Cost Effective ◽  
Multidrug Resistant ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Treatment Regimens ◽  
Development Of Resistance ◽  
Metabolic States ◽  
Animal Infection ◽  
Life Threatening

AbstractAntimicrobial resistance has been a growing concern that gradually undermines our tradition treatment regimens. The fact that few antibacterial drugs with new scaffolds or targets have been approved in the past two decades aggravates this crisis. Repurposing drugs as potent antibiotic adjuvants offers a cost-effective strategy to mitigate the development of resistance and tackle the increasing infections by multidrug-resistant (MDR) bacteria. Herein, we found that benzydamine, a widely used non‐steroidal anti‐inflammatory drug in clinic, remarkably potentiated broad-spectrum antibiotic-tetracyclines activity against a panel of clinically important pathogens, including MRSA, VRE, MCRPEC and tet(X)-positive Gram-negative bacteria. Mechanistic studies showed that benzydamine dissipated membrane potential (▵Ψ) in both Gram-positive and Gram-negative bacteria, which in turn upregulated the transmembrane proton gradient (▵pH) and promoted the uptake of tetracyclines. Additionally, benzydamine exacerbated the oxidative stress by triggering the production of ROS and suppressing GAD system-mediated oxidative defensive. This mode of action explains the great bactericidal activity of the doxycycline-benzydamine combination against different metabolic states of bacteria involve persister cells. As a proof-of-concept, the in vivo efficacy of this drug combination was evidenced in multiple animal infection models. These findings indicate that benzydamine is a potential tetracyclines adjuvant to address life-threatening infections by MDR bacteria.

Green Synthesis of Silver Nanoparticles Using Aqueous Floral Extract of Nelumbo Nucifera

2013 ◽  
Vol 756 ◽  
pp. 106-111 ◽  
Author(s):  
Selvaraj Arokiyaraj ◽  
Udaya Prakash Nyayiru Kannaian ◽  
Vijay Elakkya ◽  
T. Kamala ◽  
S. Bhuvaneswari ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Chemical Reduction ◽  
Colour Change ◽  
Cost Effective ◽  
Nelumbo Nucifera ◽  
Resonance Band ◽  
Afm Analysis ◽  
Reduction Methods ◽  
Physical And Chemical

The aim of the present study is to synthesize silver nanoparticles, using an aqueous floral extract of common Lotus, i.e Nelumbo nucifera. The synthesized nanoparticles were characterized using UV, TEM, EDX, AFM & XRD. The synthesized AgNPs were confirmed due to the colour change from colourless to reddish brown just after the addition of the aqueous floral extract of Nelumbo nucifera. The UV results of AgNPs showed the excitation of surface Plasmon resonance band at 427 nm. TEM results showed that the synthesized AgNPs were uniformed; monodispersed,spherical in shape and the particle size were found to be 77.81 ± 3.54 nm. EDX spectrum of AgNPs confirms strong signals from Ag (64%) and other elements such as C, O and Cl. The morphology of the synthesized AgNPs by AFM analysis resembled the TEM micrograph. The crystalline nature of the AgNPs was confirmed by XRD. The present study concludes that the aqueous floral extract of Nelumbo nucifera could be used as an effective reducing agent for the synthesis of AgNP. The green synthesis ofsilver nanoparticles is non-toxic and cost-effective and thus remains to be an alternative method to other physical and chemical reduction methods.

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