scholarly journals Surface Coating-Modulated Phytotoxic Responses of Silver Nanoparticles in Plants and Freshwater Green Algae

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 24
Author(s):  
Renata Biba ◽  
Karla Košpić ◽  
Bruno Komazec ◽  
Dora Markulin ◽  
Petra Cvjetko ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Surface Coating ◽  
Freshwater Algae ◽  
Growth Physiology ◽  
Gene And Protein Expression ◽  
Wide Range ◽  
Overall Stability ◽  
Particle Size And Shape ◽  
Coating Agents ◽  
Transformation Processes

Silver nanoparticles (AgNPs) have been implemented in a wide range of commercial products, resulting in their unregulated release into aquatic as well as terrestrial systems. This raises concerns over their impending environmental effects. Once released into the environment, they are prone to various transformation processes that modify their reactivity. In order to increase AgNP stability, different stabilizing coatings are applied during their synthesis. However, coating agents determine particle size and shape and influence their solubility, reactivity, and overall stability as well as their behavior and transformations in the biological medium. In this review, we attempt to give an overview on how the employment of different stabilizing coatings can modulate AgNP-induced phytotoxicity with respect to growth, physiology, and gene and protein expression in terrestrial and aquatic plants and freshwater algae.

scholarly journals Reactivity and Chemical Sintering of Carey Lea Silver Nanoparticles

Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1525
Author(s):  
Sergey Vorobyev ◽  
Elena Vishnyakova ◽  
Maxim Likhatski ◽  
Alexander Romanchenko ◽  
Ivan Nemtsev ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Silver Nanoparticles ◽  
Flexible Electronics ◽  
Photoelectron Spectroscopy ◽  
Colloidal Solutions ◽  
Ag Nps ◽  
Wide Range ◽  
Carboxylic Groups ◽  
The Media ◽  
Sulfide Ions

Carey Lea silver hydrosol is a rare example of very concentrated colloidal solutions produced with citrate as only protective ligands, and prospective for a wide range of applications, whose properties have been insufficiently studied up to now. Herein, the reactivity of the immobilized silver nanoparticles toward oxidation, sulfidation, and sintering upon their interaction with hydrogen peroxide, sulfide ions, and chlorocomplexes of Au(III), Pd(II), and Pt(IV) was investigated using SEM and X-ray photoelectron spectroscopy (XPS). The reactions decreased the number of carboxylic groups of the citrate-derived capping and promoted coalescence of 7 nm Ag NPs into about 40 nm ones, excluding the interaction with hydrogen peroxide. The increased nanoparticles form loose submicrometer aggregates in the case of sulfide treatment, raspberry-like micrometer porous particles in the media containing Pd(II) chloride, and densely sintered particles in the reaction with inert H2PtCl6 complexes, probably via the formation of surface Ag-Pt alloys. The exposure of Ag NPs to HAuCl4 solution produced compact Ag films along with nanocrystals of Au metal and minor Ag and AgCl. The results are promising for chemical ambient temperature sintering and rendering silver-based nanomaterials, for example, for flexible electronics, catalysis, and other applications.

scholarly journals Preparation of Silver Nanoparticles and Their Industrial and Biomedical Applications: A Comprehensive Review

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Adnan Haider ◽  
Inn-Kyu Kang
Keyword(s):  
Silver Nanoparticles ◽  
Biomedical Applications ◽  
Consumer Products ◽  
Ag Nps ◽  
New Techniques ◽  
Governing Factor ◽  
Wide Range ◽  
Microbial Proliferation ◽  
Synthetic Routes ◽  
Biomedical Fields

Silver nanoparticles (Ag-NPs) have diverted the attention of the scientific community and industrialist itself due to their wide range of applications in industry for the preparation of consumer products and highly accepted application in biomedical fields (especially their efficacy against microbes, anti-inflammatory effects, and wound healing ability). The governing factor for their potent efficacy against microbes is considered to be the various mechanisms enabling it to prevent microbial proliferation and their infections. Furthermore a number of new techniques have been developed to synthesize Ag-NPs with controlled size and geometry. In this review, various synthetic routes adapted for the preparation of the Ag-NPs, the mechanisms involved in its antimicrobial activity, its importance/application in commercial as well as biomedical fields, and possible application in future have been discussed in detail.

scholarly journals Developmental exposure to silver nanoparticles leads to long term gut dysbiosis and neurobehavioral alterations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhen Lyu ◽  
Shreya Ghoshdastidar ◽  
Karamkolly R. Rekha ◽  
Dhananjay Suresh ◽  
Jiude Mao ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Body Fat ◽  
Repetitive Behaviors ◽  
Developmental Exposure ◽  
Male And Female ◽  
Female Mice ◽  
Gut Dysbiosis ◽  
Study Results ◽  
Wide Range

AbstractDue to their antimicrobial properties, silver nanoparticles (AgNPs) are used in a wide range of consumer products that includes topical wound dressings, coatings for biomedical devices, and food-packaging to extend the shelf-life. Despite their beneficial antimicrobial effects, developmental exposure to such AgNPs may lead to gut dysbiosis and long-term health consequences in exposed offspring. AgNPs can cross the placenta and blood–brain-barrier to translocate in the brain of offspring. The underlying hypothesis tested in the current study was that developmental exposure of male and female mice to AgNPs disrupts the microbiome–gut–brain axis. To examine for such effects, C57BL6 female mice were exposed orally to AgNPs at a dose of 3 mg/kg BW or vehicle control 2 weeks prior to breeding and throughout gestation. Male and female offspring were tested in various mazes that measure different behavioral domains, and the gut microbial profiles were surveyed from 30 through 120 days of age. Our study results suggest that developmental exposure results in increased likelihood of engaging in repetitive behaviors and reductions in resident microglial cells. Echo-MRI results indicate increased body fat in offspring exposed to AgNPs exhibit. Coprobacillus spp., Mucispirillum spp., and Bifidobacterium spp. were reduced, while Prevotella spp., Bacillus spp., Planococcaceae, Staphylococcus spp., Enterococcus spp., and Ruminococcus spp. were increased in those developmentally exposed to NPs. These bacterial changes were linked to behavioral and metabolic alterations. In conclusion, developmental exposure of AgNPs results in long term gut dysbiosis, body fat increase and neurobehavioral alterations in offspring.

scholarly journals Biogenic Synthesis of Silver Nanoparticles with Antimicrobial Properties

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Evangelia A Pavlatou
Keyword(s):  
Silver Nanoparticles ◽  
Antimicrobial Properties ◽  
Public Health Problem ◽  
Integrated Approach ◽  
Synthetic Methods ◽  
Synthesis Process ◽  
Major Public Health Problem ◽  
Biogenic Synthesis ◽  
Wide Range ◽  
Bacteria And Fungi

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.

scholarly journals Antioxidant and cytotoxic studies of Acacia nilotica twig extract and their green synthesized silver nanoparticles

2020 ◽  
Vol 9 (2) ◽  
pp. 975-980 ◽  
Keyword(s):  
Antioxidant Activity ◽  
Silver Nanoparticles ◽  
Cell Lines ◽  
Antioxidant Activities ◽  
Reducing Power ◽  
Acacia Nilotica ◽  
Total Phenolic ◽  
Hek 293 ◽  
Selected Area Electron Diffraction ◽  
Wide Range

Acacia nilotica (L.) Delile is well known as “Desi Kikar”or Babul in India that possesses a wide range of pharmacological activities. In the present study, Acacia nilotica twig extract and its synthesized silver nanoparticles (AgNPs) were evaluated for total phenolic content (TPC), antioxidant activity and cytotoxic effects. Characterization of AgNPs was done by UV-Visible spectroscopy, Fourier-transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM) and Selected area electron diffraction (SAED) techniques. Antioxidant potential was determined using different assays including 2,2-diphenyl-1-picrylhydrazyl (DPPH), reducing power and β-carotene linoleic acid. Cytotoxicity was tested by 3-(4,5-dimethyl-2-yl)-2,5-diphynyl tetrazolium bromide (MTT) assay on Human embryonic kidney (HEK)-293 cell lines. The results indicated that AgNPs exhibited higher antioxidant activity (81.11 %) and TPC (57.35 mg of GAE/mL of extract) as compare to plant extract. A positive correlation was observed between the TPC and antioxidant activities. The inhibitory concentration (IC50) of A. nilotica extract and AgNPs was 52.08µg/mL and 56.82µg/mL respectively. Cytotoxicity against HEK-293 cell lines was dose dependent. Accordingly, it is summarized that A. nilotica based AgNPs could serve as a potential antioxidant for therapeutic purposes.

scholarly journals Ultraviolet Irradiation Enhances the Microbicidal Activity of Silver Nanoparticles by Hydroxyl Radicals

2020 ◽  
Vol 21 (9) ◽  
pp. 3204 ◽  
Author(s):  
Shingo Nakamura ◽  
Naoko Ando ◽  
Masahiro Sato ◽  
Masayuki Ishihara
Keyword(s):  
Silver Nanoparticles ◽  
Uv Radiation ◽  
Hydroxyl Radicals ◽  
Healthcare Workers ◽  
Direct Detection ◽  
Ultraviolet A ◽  
Microbicidal Activity ◽  
Wide Range ◽  
Spin Resonance ◽  
Rapid Generation

It is known that silver has microbicidal qualities; even at a low concentration, silver is active against many kinds of bacteria. Silver nanoparticles (AgNPs) have been extensively studied for a wide range of applications. Alternately, the toxicity of silver to human cells is considerably lower than that to bacteria. Recent studies have shown that AgNPs also have antiviral activity. We found that large amounts of hydroxyl radicals—highly reactive molecular species—are generated when AgNPs are irradiated with ultraviolet (UV) radiation with a wavelength of 365 nm, classified as ultraviolet A (UVA). In this study, we used electron spin resonance direct detection to confirm that UV irradiation of AgNPs produced rapid generation of hydroxyl radicals. As hydroxyl radicals are known to degrade bacteria, viruses, and some chemicals, the enhancement of the microbicidal activity of AgNPs by UV radiation could be valuable for the protection of healthcare workers and the prevention of the spread of infectious diseases.

scholarly journals Biosynthesis and characterization of silver nanoparticles using Ochradenus arabicus and their physiological effect on Maerua oblongifolia raised in vitro

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hassan O. Shaikhaldein ◽  
Fahad Al-Qurainy ◽  
Mohammad Nadeem ◽  
Salim Khan ◽  
Mohamed Tarroum ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Chlorophyll Content ◽  
Total Protein ◽  
Dry Weight ◽  
Shoot Length ◽  
Antioxidant Enzyme Activities ◽  
Fresh Weight ◽  
Wide Range ◽  
Shoot Number

Abstract Silver nanoparticles (AgNPs) are presently the most commonly generated engineered nanomaterials and are found in a wide range of agro-commercial products. The present study was designed to synthesize AgNPs biologically using Ochradenus arabicus leaves and investigate their effect on the morphophysiological properties of Maerua oblongifolia raised in vitro. Physicochemical methods (ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy, and transmission electron microscopy were performed for characterization and for obtaining microphotographs of the AgNPs. Shoots of M. oblongifolia (2–3 cm) grown in Murashige and Skoog medium supplemented with different concentrations of AgNPs (0, 10, 20, 30, 40, or 50 mg L−1) were used. Following 6 weeks of in vitro shoot regeneration, the shoot number, shoot length, leaf number, fresh weight, dry weight, chlorophyll content, total protein, proline level, and antioxidant enzyme activities of the plants were quantified. We found that 20 mg L−1 AgNPs increased the shoot number, shoot length, fresh weight, dry weight, and chlorophyll content of the plants. The maximum total protein was recorded in plants that were administered the lowest dose of AgNPs (10 mg L−1), while high concentrations of AgNPs (40 and 50 mg L−1) increased the levels of proline and the enzymes superoxide dismutase and catalase. Our results indicate that green-synthesized AgNPs may be of agricultural and medicinal interest owing to their effects on plants in vitro.

Combined Toxicity of Silver Nanoparticles with Hematite or Plastic Nanoparticles toward Two Freshwater Algae

2019 ◽  
Vol 53 (7) ◽  
pp. 3871-3879 ◽  
Author(s):  
Bin Huang ◽  
Zhong-Bo Wei ◽  
Liu-Yan Yang ◽  
Ke Pan ◽  
Ai-Jun Miao
Keyword(s):  
Silver Nanoparticles ◽  
Freshwater Algae ◽  
Combined Toxicity

scholarly journals New Relevant Descriptor of Linear QNAR Models for Toxicity Assessment of Silver Nanoparticles

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1459
Author(s):  
Alexey Kudrinskiy ◽  
Pavel Zherebin ◽  
Alexander Gusev ◽  
Olga Shapoval ◽  
Jaeho Pyee ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Biological Activity ◽  
Colloidal Stability ◽  
Chemical Nature ◽  
Equilibrium Concentration ◽  
Toxicity Assessment ◽  
Yeast Cells ◽  
Wide Range ◽  
Silver Nps ◽  
Living Organisms

The use of silver nanoparticles (NPs) in medical, industrial and agricultural fields is becoming more widespread every year. This leads to an increasing number of experimental toxicological and microbiological studies of silver NPs aimed at establishing the risk–benefit ratio for their application. The following key parameters affecting the biological activity of silver dispersions are traditionally taken into consideration: mean diameter of NPs, surface potential of NPs and equilibrium concentration of Ag+. These characteristics are mainly predetermined by the chemical nature of the capping agent used for stabilization. However, the extent to which they influence the biological activity and the toxicity of silver NPs varies greatly. In this work, dispersions of silver NPs stabilized with a wide array of substances of different chemical nature were used for quantitative evaluation of whether the various measurable properties of silver NPs fit as descriptors of linear QNAR (quantitative nanostructure–activity relationship) models for silver NP toxicity evaluation with respect to a model eukaryotic microorganism—Saccharomyces cerevisiae yeast cells. It was shown that among the factors that determine silver NP toxicity, the charge of particles, their colloidal stability and the ability to generate Ag+ ions carry more importance than the descriptors related to the particle size. A significant synergistic effect between the ζ-potential and the colloidal stability of silver NPs on their toxicity was also discovered. Following this, a new descriptor has been proposed for the integral characterization of the silver dispersion colloidal stability. According to the obtained data, it can be considered applicable for building QNAR models of higher efficacy. The validity testing of the proposed model for theoretical prediction of silver NP toxicity using a wide range of living organisms has shown that this new descriptor correlates with toxicity much better compared to most traditionally used descriptors. Consequently, it seems promising in terms of being used not only in situations involving the rather narrow array of the objects tested, but also for the construction of silver NP toxicity models with respect to other living organisms.

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