Size-Dependent Bioactivity of Silver Nanoparticles: Antibacterial Properties, Influence on Copper Status in Mice, and Whole-Body Turnover

Silver nanoparticles (AgNPs) have been proven to have potent antibacterial properties, offering an attractive alternative to antibiotics in the treatment of several infections such as otitis media. Concerns have been raised though regarding their toxicity. There are few data regarding the toxic effects of AgNPs in cochlear cells. The aim of our study was to evaluate the effects of AgNPs of four sizes as a function of their size on HEI-OC1 cochlear cells and on HaCaT keratinocytes. The cells were treated with different concentrations of AgNPs. We evaluated silver uptake by atomic absorption spectroscopy and transmission electron microscopy (TEM), cytotoxicity with the alamarBlue test, ROS production with 2′,7′-dichloro-dihydro-fluorescein diacetate, and genotoxicity with the comet assay. Silver intracellular concentration increased proportionally with the incubation time and the size of the NPs. Silver uptake was higher in HEI-OC1 cells compared to HaCaT. While after 4 h exposure, only the 50 nm NPs were observed in both cell lines and only the 5 nm NPs were observed in the HaCaT cells, after 24 h, nanoparticles of all sizes could be visualized in both cell lines. The cells showed signs of distress: vacuolizations, autophagosomes, signs of apoptosis, or cellular debris. AgNPs of all sizes reduced viability proportionally with the concentration, HEI-OC1 cells being more affected. The toxicity of AgNPs decreased with the nanoparticle size, and ROS production was dose and size dependent, mainly in the cochlear cells. Genotoxicity assessed by comet assay revealed a higher level of DNA lesions in HEI-OC1 cells after treatment with small-sized AgNPs. The perspective of using AgNPs in the treatment of otitis media, although very attractive, must be regarded with caution: cochlear cells proved to be more sensitive to the toxic effect of AgNPs compared to other cell lines. Potential treatments must be tailored specifically, choosing NPs with minimum toxicity towards auditory cells.

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Green synthesised silver nanoparticles incorporated electrospun poly(methyl methacrylate) nanofibers with different architectures for ophthalmologic alternatives

Journal of Bioactive and Compatible Polymers ◽

10.1177/0883911521997856 ◽

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.

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Exposure Media and Nanoparticle Size Influence on the Fate, Bioaccumulation, and Toxicity of Silver Nanoparticles to Higher Plant Salvinia minima

Molecules ◽

10.3390/molecules26082305 ◽

2021 ◽

Vol 26 (8) ◽

pp. 2305

Author(s):

Melusi Thwala ◽

Stephen Klaine ◽

Ndeke Musee

Keyword(s):

Silver Nanoparticles ◽

Analytical Techniques ◽

Hard Water ◽

Higher Plant ◽

X Ray ◽

Chlorophyll Pigments ◽

Size Dependent ◽

Predicted Environmental Concentrations ◽

Low Exposure ◽

Toxicity Pattern

Silver nanoparticles (AgNPs) are favoured antibacterial agents in nano-enabled products and can be released into water resources where they potentially elicit adverse effects. Herein, interactions of 10 and 40 nm AgNPs (10-AgNPs and 40-AgNPs) with aquatic higher plant Salvinia minima at 600 µg/L in moderately hard water (MHW), MHW of raised calcium (Ca2+), and MHW containing natural organic matter (NOM) were examined. The exposure media variants altered the AgNPs’ surface properties, causing size-dependent agglomeration. The bio-accessibility in the ascending order was: NOM < MHW < Ca2+, was higher in plants exposed to 10-AgNPs, and across all exposures, accumulation was higher in roots compared to fronds. The AgNPs reduced plant growth and the production of chlorophyll pigments a and b; the toxic effects were influenced by exposure media chemistry, and the smaller 10-AgNPs were commonly the most toxic relative to 40-AgNPs. The toxicity pattern was linked to the averagely higher dissolution of 10-AgNPs compared to the larger counterparts. The scanning electron microscopy and X-ray fluorescence analytical techniques were found limited in examining the interaction of the plants with AgNPs at the low exposure concentration used in this study, thus challenging their applicability considering the even lower predicted environmental concentrations AgNPs.

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The Synergistic Effect of Biosynthesized Silver Nanoparticles and Phage ZCSE2 as a Novel Approach to Combat Multidrug-Resistant Salmonella enterica

Antibiotics ◽

10.3390/antibiotics10060678 ◽

2021 ◽

Vol 10 (6) ◽

pp. 678

Author(s):

Abdallah S. Abdelsattar ◽

Rana Nofal ◽

Salsabil Makky ◽

Anan Safwat ◽

Amera Taha ◽

...

Keyword(s):

Silver Nanoparticles ◽

Color Change ◽

Antibacterial Properties ◽

Multidrug Resistant ◽

Inhibitory Effect ◽

Health Concern ◽

Resistant Bacteria ◽

Mortality And Morbidity ◽

Novel Approach ◽

Transmission Electron

The emergence and evolution of antibiotic-resistant bacteria is considered a public health concern. Salmonella is one of the most common pathogens that cause high mortality and morbidity rates in humans, animals, and poultry annually. In this work, we developed a combination of silver nanoparticles (AgNPs) with bacteriophage (phage) as an antimicrobial agent to control microbial growth. The synthesized AgNPs with propolis were characterized by testing their color change from transparent to deep brown by transmission electron microscopy (TEM) and Fourier-Transform Infrared Spectroscopy (FTIR). The phage ZCSE2 was found to be stable when combined with AgNPs. Both minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated for AgNPs, phage, and their combination. The results indicated that MIC and MBC values were equal to 23 µg/mL against Salmonella bacteria at a concentration of 107 CFU/mL. The combination of 0.4× MIC from AgNPs and phage with Multiplicity of Infection (MOI) 0.1 showed an inhibitory effect. This combination of AgNPs and phage offers a prospect of nanoparticles with significantly enhanced antibacterial properties and therapeutic performance.

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Preparation and characterization of agar/lignin/silver nanoparticles composite films with ultraviolet light barrier and antibacterial properties

Food Hydrocolloids ◽

10.1016/j.foodhyd.2017.05.002 ◽

2017 ◽

Vol 71 ◽

pp. 76-84 ◽

Cited By ~ 76

Author(s):

Shiv Shankar ◽

Jong-Whan Rhim

Keyword(s):

Silver Nanoparticles ◽

Ultraviolet Light ◽

Composite Films ◽

Antibacterial Properties ◽

Light Barrier

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Sodium alginate-based nanocomposite films with strong antioxidant and antibacterial properties enhanced by polyphenol-rich kiwi peel extracts bio-reduced silver nanoparticles

Food Packaging and Shelf Life ◽

10.1016/j.fpsl.2021.100741 ◽

2021 ◽

Vol 29 ◽

pp. 100741

Author(s):

Xinyu Sun ◽

Hui Zhang ◽

Jiao Wang ◽

Mengna Dong ◽

Pei Jia ◽

...

Keyword(s):

Silver Nanoparticles ◽

Sodium Alginate ◽

Antibacterial Properties ◽

Nanocomposite Films

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Green Synthesis, Characterization, and Antibacterial Properties of Silver Nanoparticles Obtained by Using Diverse Varieties of Cannabis sativa Leaf Extracts

Molecules ◽

10.3390/molecules26134041 ◽

2021 ◽

Vol 26 (13) ◽

pp. 4041

Author(s):

Adriana Cecilia Csakvari ◽

Cristian Moisa ◽

Dana G. Radu ◽

Leonard M. Olariu ◽

Andreea I. Lupitu ◽

...

Keyword(s):

Silver Nanoparticles ◽

Green Synthesis ◽

Antioxidant Capacity ◽

Cannabis Sativa ◽

Antibacterial Properties ◽

Green Building ◽

Human Pathogens ◽

Leaf Extracts ◽

Vis Spectroscopy ◽

Ft Ir

Cannabis sativa L. (hemp) is a plant used in the textile industry and green building material industry, as well as for the phytoremediation of soil, medical treatments, and supplementary food products. The synergistic effect of terpenes, flavonoids, and cannabinoids in hemp extracts may mediate the biogenic synthesis of metal nanoparticles. In this study, the chemical composition of aqueous leaf extracts of three varieties of Romanian hemp (two monoecious, and one dioecious) have been determined by Fourier-Transformed Infrared spectroscopy (FT-IR), high-performance liquid chromatography, and mass spectrometry (UHPLC-DAD-MS). Then, their capability to mediate the green synthesis of silver nanoparticles (AgNPs) and their pottential antibacterial applications were evaluated. The average antioxidant capacity of the extracts had 18.4 ± 3.9% inhibition determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 78.2 ± 4.1% determined by 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS™) assays. The total polyphenolic content of the extracts was 1642 ± 32 mg gallic acid equivalent (GAE) L−1. After this, these extracts were reacted with an aqueous solution of AgNO3 resulting in AgNPs, which were characterized by UV−VIS spectroscopy, FT-IR, scanning electron microscopy (SEM-EDX), and dynamic light scattering (DLS). The results demonstrated obtaining spherical, stable AgNPs with a diameter of less than 69 nm and an absorbance peak at 435 nm. The mixture of extracts and AgNPs showed a superior antioxidant capacity of 2.3 ± 0.4% inhibition determined by the DPPH• assay, 88.5 ± 0.9% inhibition as determined by the ABTS•+ assay, and a good antibacterial activity against several human pathogens: Escherichia coli, Klebsiella pneumoniae, Pseudomonas fluorescens, and Staphylococcus aureus.

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