Antimicrobial properties of nanofiltration membranes modified with silver nanoparticles

Author(s):  
Renat Khaydarov ◽  
Olga Gapurova ◽  
Murodjon Abdukhakimov ◽  
Ilkham Sadikov ◽  
Ilnur Garipov ◽  
...  
Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 317
Author(s):  
HanGoo Kang ◽  
Jinwon Seo ◽  
Eun-Jeong Yang ◽  
In-Hong Choi

Silver nanoparticles (AgNPs) are widely used in various fields because of their antimicrobial properties. However, many studies have reported that AgNPs can be harmful to both microorganisms and humans. Reactive oxygen species (ROS) are a key factor of cytotoxicity of AgNPs in mammalian cells and an important factor in the immune reaction of neutrophils. The immune reactions of neutrophils include the expulsion of webs of DNA surrounded by histones and granular proteins. These webs of DNA are termed neutrophil extracellular traps (NETs). NETs allow neutrophils to catch and destroy pathogens in extracellular spaces. In this study, we investigated how AgNPs stimulate neutrophils, specifically focusing on NETs. Freshly isolated human neutrophils were treated with 5 or 100 nm AgNPs. The 5 nm AgNPs induced NET formation, but the 100 nm AgNPs did not. Subsequently, we investigated the mechanism of AgNP-induced NETs using known inhibitors related to NET formation. AgNP-induced NETs were dependent on ROS, peptidyl arginine deiminase, and neutrophil elastase. The result in this study indicates that treatment of 5 nm AgNPs induce NET formation through histone citrullination by peptidyl arginine deiminase and histone cleavage by neutrophil elastase.


2021 ◽  
pp. 130233
Author(s):  
A. Kalam ◽  
A.G. Al-Sehemi ◽  
S. Alrumman ◽  
M.A. Assiri ◽  
A.M. Alfaify ◽  
...  

2021 ◽  
Author(s):  
Jelena S. Katanić Stanković ◽  
◽  
Nikola Srećković ◽  
Vladimir Mihailović

In this study, silver nanoparticles (AgNPs) have been synthesized using the aqueous extract of the aerial parts of B. purpurocaerulea, collected in Serbia. B. purpurocaerulea silver nanoparticles (Bp– AgNPs) synthesis was confirmed using UV-Vis spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). The biological potential of synthesized Bp-AgNPs was evaluated in vitro using ABTS assay for determining free radical scavenging potential and microdilution method for analysis of antimicrobial properties. Bp-AgNPs showed high antioxidant activity similar to Bp-extract, comparable to BHT. The synthesized nanoparticles exerted remarkable antibacterial effects, with minimal inhibitory concentration (MIC) values below 20 µg/mL. In the case of some bacterial strains, the results of Bp– AgNPs were comparable or similar to standard antibiotic erythromycin. The antifungal activity of Bp– AgNPs was moderate for most of the used strains. Nevertheless, several fungi were resistant to the NPs action, while two tested Penicillium species were extremely sensitive on Bp-AgNPs with MIC lower than 40 µg/mL. The antimicrobial properties of Bp-AgNPs can be useful for the development of new NPs-containing products.


Author(s):  
Shyla Marjorie Haqq ◽  
Amit Chattree

  This review is based on the synthesis of silver nanoparticles (AgNPs) using a green approach which is biofabricated from various medicinal plants. AgNPs were prepared from the various parts of the plants such as the flowers, stems, leaves, and fruits. Various physiochemical characterizations were performed using the ultraviolet (UV)-visible spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction spectroscopy, transmission electron microscopy, and energy dispersive spectroscopy. AgNPs were also used to inhibit the growth of bacterial pathogens and were found to be effective against both the Gram-positive and Gram-negative bacteria. For the silver to have antimicrobial properties, it must be present in the ionized form. All the forms of silver-containing compounds with the observed antimicrobial properties are in one way or another source of silver ions. Although the antimicrobial properties of silver have been known, it is thought that the silver atoms bind to the thiol groups in enzymes and subsequently leads to the deactivation of enzymes. For the silver to have antimicrobial properties, it must be present in the ionized form. The study suggested that the action of the AgNPs on the microbial cells resulted into cell lysis and DNA damage. AgNPs have proved their candidature as a potential antibacterial against the multidrug-resistant microbes. The biological agents for synthesizing AgNPs cover compounds produced naturally in microbes and plants. Reaction parameters under which the AgNPs were being synthesized hold prominent impact on their size, shape, and application. Silver nanoparticle synthesis and their application are summarized and critically discussed in this review.


2014 ◽  
Vol 28 (3) ◽  
pp. 311-317 ◽  
Author(s):  
Agnieszka Nawrocka

Abstract Silver nanoparticles have antimicrobial properties since they can be regarded as an efficient protector against pathogenic microorganisms. Fourier transform infrared spectroscopy was used to examine conformational changes in the secondary structure of wheat gluten washed out from grain treated with an aqueous solution of silver nanoparticles stabilized by tri-sodium citrate. Silver nanoparticles were used as a protective layer on the grain surface against bacterial and fungal infections (antimicrobial agent). Analysis of the amide I band revealed significant changes in the secondary structure after using silver nanoparticles. An increase in the β-sheet content (from 36.2 to 39.2%) was observed at the expense of the α-helix and β-turn content. To find factors causing these changes, the wheat grains were treated by an aqueous solution of trisodium citrate and water. The results obtained indicate that the changes in the gluten structure were connected mainly with the trisodium citrate action due to presence of a small number of free molecules of the stabilizer in the solution of silver nanoparticles. Additionally, the conformational changes in gluten pointed out that gluten flexibility increased (decrease in the αH/βS ratio from 1.40 for the control sample to 1.26 for the silver nanoparticle-treated samples) as well as the solubility of gluten decreased (decrease in the β-turn content from 13.1 to 11.4%).


Chemistry ◽  
2021 ◽  
Vol 3 (4) ◽  
pp. 1271-1285
Author(s):  
Patricia Zimet ◽  
Ruby Valadez ◽  
Sofía Raffaelli ◽  
María Belén Estevez ◽  
Helena Pardo ◽  
...  

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.


2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Evangelia A Pavlatou

The transmission of a wide range of diseases, related to the infection by pathogenic microorganisms is a major public health problem that daily endangers the safety of human population. Silver has been thoroughly studied and used against bacteria due to its antimicrobial properties. Nanostructured silver gathers all the advantages of the silver itself, as well as the advanced performance of the nanomaterials. Thus, currently, silver nanoparticles constitute the most widely used kind of nanoparticles in biomedicine, due to their attractive antimicrobial properties. A variety of physical and chemical methods are employed for the AgNPs synthesis. However, many of them include the use of toxic reagents or require large amounts of energy, during the synthesis process. For this reason, many eco-friendly methods are proposed in order to synthesize AgNPs. Hence, biogenic synthesis of AgNPs, utilizing biological resources opens a novel route for the development of alternative production processes.These methods seem to have significant advantages, as the extracts contribute positively to the formation and enhancement of the antimicrobial activity of AgNPs, also acting as protective agents of the produced particles. In this review an integrated approach of AgNPs bio-synthetic methods using microorganisms, such as bacteria and fungi, plants and plant extracts, as well as several templates, like DNA and viruses is discussed, shedding light on the comparative advantages of them.


Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7031
Author(s):  
Alina Robu ◽  
Aurora Antoniac ◽  
Elena Grosu ◽  
Eugeniu Vasile ◽  
Anca Daniela Raiciu ◽  
...  

PMMA bone cements are mainly used to fix implanted prostheses and are introduced as a fluid mixture, which hardens over time. The problem of infected prosthesis could be solved due to the development of some new antibacterial bone cements. In this paper, we show the results obtained to develop four different modified PMMA bone cements by using antimicrobial additives, such as gentamicin, peppermint oil incorporated in hydroxyapatite, and silver nanoparticles incorporated in a ceramic glass matrix (2 and 4%). The structure and morphology of the modified bone cements were investigated by SEM and EDS. We perform experimental measurements on wettability, hydration degree, and degradation degree after immersion in simulated body fluid. The cytotoxicity was evaluated by MTT assay using the human MG-63 cell line. Antimicrobial properties were checked against standard strains Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. The addition of antimicrobial agents did not significantly affect the hydration and degradation degree. In terms of biocompatibility assessed by the MTT test, all experimental PMMA bone cements are biocompatible. The performance of bone cements with peppermint essential oil and silver nanoparticles against these two pathogens suggests that these antibacterial additives look promising to be used in clinical practice against bacterial infection.


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