Silver nanoparticles functionalized with a fluorescent cyclic RGD peptide: a versatile integrin targeting platform for cells and bacteria

RSC Advances ◽  
2016 ◽  
Vol 6 (113) ◽  
pp. 112381-112392 ◽  
Author(s):  
P. Di Pietro ◽  
L. Zaccaro ◽  
D. Comegna ◽  
A. Del Gatto ◽  
M. Saviano ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Silver Nanoparticle ◽  
Rgd Peptide ◽  
Integrin Receptors ◽  
Green Fluorescent ◽  
In Cells

A green fluorescent RGD peptide–silver nanoparticle platform to target integrin receptors in cells and bacterial studies.

Detection of intracellular silver nanoparticles using flow cytometry

2018 ◽  
pp. 223-226
Author(s):  
С.И. Каба ◽  
А.А. Соколовская
Keyword(s):  
Flow Cytometry ◽  
Silver Nanoparticles ◽  
Endothelial Cells ◽  
Silver Nanoparticle ◽  
Cell Uptake ◽  
Control Samples

Продемонстрировано обнаружение наночастиц серебра во внутриклеточном пространстве с помощью проточной цитофлуориметрии. В эндотелиальных клетках линии EA.hy926, инкубированных в растворе, содержащем 2 мкг/мл наносеребра, измеряли боковое светорассеяние. По сравнению с контрольными образцами этот параметр возрастал, в то время как прочие значимые характеристики не изменялись. Это подтверждает чувствительность метода к изменившемуся состоянию клеток и указывает на поглощение наночастиц серебра клетками при концентрации ниже токсической. The study demonstrated a possibility for detection of intracellular silver nanoparticles using flow cytometry. The parameter used in this work, side scattering, was measured in EA.hy926 endothelial cells incubated in a 2 mg/ml silver nanoparticle solution. This parameter was increased compared to control samples. Therefore, this technique was sensitive to changes in the cell status and suggested the cell uptake of the particles under the subtoxic conditions.

Annona muricata silver nanoparticles exhibit strong anticancer activities against cervical and prostate adenocarcinomas through regulation of CASP9 and the CXCL1/CXCR2 genes axis

Tumor Biology ◽  
2021 ◽  
Vol 43 (1) ◽  
pp. 37-55
Author(s):  
Yahaya Gavamukulya ◽  
Esther N. Maina ◽  
Hany A. El-Shemy ◽  
Amos M. Meroka ◽  
Geoffrey K. Kangogo ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Anticancer Drugs ◽  
Hela Cells ◽  
Selectivity Index ◽  
Annona Muricata ◽  
Anticancer Activities ◽  
Apoptosis Pathway ◽  
Migration Assay ◽  
Intrinsic Apoptosis Pathway ◽  
In Cells

BACKGROUND: Green synthesized nanoparticles have been earmarked for use in nanomedicine including for the development of better anticancer drugs. OBJECTIVE: The aim of this study was to undertake biochemical evaluation of anticancer activities of green synthesized silver nanoparticles (AgNPs) from ethanolic extracts of fruits (AgNPs-F) and leaves (AgNPs-L) of Annona muricata. METHODS: Previously synthesized silver nanoparticles were used for the study. The effects of the AgNPs and 5-Fluorouracil were studied on PC3, HeLa and PNT1A cells. The resazurin, migration and colonogenic assays as well as qRT-PCR were employed. RESULTS: The AgNPs-F displayed significant antiproliferative effects against HeLa cells with an IC50 of 38.58μg/ml and PC3 cells with an IC50 of 48.17μg/ml but selectively spared normal PNT1A cells (selectivity index of 7.8), in comparison with first line drug 5FU and AgNPs-L whose selectivity index were 3.56 and 2.26 respectively. The migration assay revealed potential inhibition of the metastatic activity of the cells by the AgNPs-F while the colonogenic assay indicated the permanent effect of the AgNPs-F on the cancer cells yet being reversible on the normal cells in contrast with 5FU and AgNPs-L. CASP9 was significantly over expressed in all HeLa cells treated with the AgNPs-F (1.53-fold), AgNPs-L (1.52-fold) and 5FU (4.30-fold). CXCL1 was under expressed in HeLa cells treated with AgNPs-F (0.69-fold) and AgNPs-L (0.58-fold) and over expressed in cells treated with 5FU (4.95-fold), but the difference was not statistically significant. CXCR2 was significantly over expressed in HeLa cells treated with 5FU (8.66-fold) and AgNPs-F (1.12-fold) but under expressed in cells treated with AgNPs-L (0.76-fold). CONCLUSIONS: Here we show that biosynthesized AgNPs especially AgNPs-F can be used in the development of novel and better anticancer drugs. The mechanism of action of the AgNPs involves activation of the intrinsic apoptosis pathway through upregulation of CASP9 and concerted down regulation of the CXCL1/ CXCR2 gene axis.

scholarly journals A comparative study of silver nanoparticle dissolution under physiological conditions

2020 ◽  
Vol 2 (12) ◽  
pp. 5760-5768
Author(s):  
Lukas Steinmetz ◽  
Christoph Geers ◽  
Sandor Balog ◽  
Mathias Bonmarin ◽  
Laura Rodriguez-Lorenzo ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Comparative Study ◽  
Silver Nanoparticle ◽  
Biologically Relevant ◽  
Physiological Conditions ◽  
Aggregation Behaviour

The dissolution and aggregation behaviour of silver nanoparticles under physiological conditions and in biologically relevant environments is investigated by exploiting their plasmonic properties.

scholarly journals Asc Modulates the Function of NLRC4 in Response to Infection of Macrophages by Legionella pneumophila

mBio ◽  
2011 ◽  
Vol 2 (4) ◽  
Author(s):  
Christopher L. Case ◽  
Craig R. Roy
Keyword(s):  
Cell Death ◽  
Legionella Pneumophila ◽  
Fluorescent Protein ◽  
Microbial Infection ◽  
Content Type ◽  
Caspase 1 ◽  
Cell Death Pathway ◽  
Dependent Cell ◽  
Green Fluorescent ◽  
In Cells

ABSTRACTNucleotide-binding domain, leucine-rich repeat containing proteins (NLRs) activate caspase-1 in response to a variety of bacterium-derived signals in macrophages. NLR-mediated activation of caspase-1 byLegionella pneumophilaoccurs through both an NLRC4/NAIP5-dependent pathway and a pathway requiring the adapter protein Asc. Both pathways are needed for maximal activation of caspase-1 and for the release of the cytokines interleukin-1β (IL-1β) and IL-18. Asc is not required for caspase-1-dependent pore formation and cell death induced upon infection of macrophages byL. pneumophila. Here, temporal and spatial localization of caspase-1-dependent processes was examined to better define the roles of Asc and NLRC4 during infection. Imaging studies revealed that caspase-1 localized to a single punctate structure in infected cells containing Asc but not in cells lacking this adapter. Both endogenous Asc and ectopically produced NLRC4 tagged with green fluorescent protein (GFP) were found to localize to caspase-1 puncta followingL. pneumophilainfection, suggesting that NLRC4 and Asc coordinate signaling through this complex during caspase-1 activation. Formation of caspase-1-containing puncta correlated with caspase-1 processing, suggesting a role for the Asc/NLRC4/caspase-1 complex in caspase-1 cleavage. In cells deficient for Asc, NLRC4 did not assemble into discrete puncta, and pyroptosis occurred at an accelerated rate. These data indicate that Asc mediates integration of NLR components into caspase-1 processing platforms and that recruitment of NLR components into an Asc complex can dampen pyroptotic responses. Thus, a negative feedback role of complexes containing Asc may be important for regulating caspase-1-mediated responses during microbial infection.IMPORTANCECaspase-1 is a protease activated during infection that is central to the regulation of several innate immune pathways. Studies examining the macromolecular complexes containing this protein, known as inflammasomes, have provided insight into the regulation of this protease. This work demonstrates that the intracellular bacteriumLegionella pneumophilainduces formation of complexes containing caspase-1 by multiple mechanisms and illustrates that an adapter molecule called Asc integrates signals from multiple independent upstream caspase-1 activators in order to assemble a spatially distinct complex in the macrophage. There were caspase-1-associated activities such as cytokine processing and secretion that were controlled by Asc. Importantly, this work uncovered a new role for Asc in dampening a caspase-1-dependent cell death pathway called pyroptosis. These findings suggest that Asc plays a central role in controlling a distinct subset of caspase-1-dependent activities by both assembling complexes that are important for cytokine processing and suppressing processes that mediate pyroptosis.

scholarly journals Stable Surface Technology for HER Electrodes

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 693
Author(s):  
Hong Soo Kim ◽  
Hwapyong Kim ◽  
Monica Claire Flores ◽  
Gyu-Seok Jung ◽  
Su-Il In
Keyword(s):  
Silver Nanoparticles ◽  
Stainless Steel ◽  
Noble Metal ◽  
Silver Nanoparticle ◽  
Alternative Energy ◽  
Water Electrolysis ◽  
Active Surface ◽  
Plasma Coating ◽  
Surface Shape ◽  
Active Surface Area

With the rapid increase in energy consumption worldwide, the development of renewable and alternative energy sources can sustain long-term development in the energy field. Hydrogen (H2), which is one of the clean chemical fuels, has the highest weight energy density and its combustion byproduct is only water. Among the various methods of producing hydrogen source, water electrolysis is a process that can effectively produce H2. However, it is difficult for commercialization of water electrolysis for H2 production due to the high cost and low abundance of noble metal-based cathodic electrode used for highly efficiency. Several studies have been conducted to reduce noble metal loading and/or completely replace them with other materials to overcome these obstacles. Among them, stainless steel contains many components of transition metals (Ni, Cr, Co) but have sluggish reaction kinetics and small active surface area. In this study, the problem of stainless steel was to be solved by utilizing the electrocatalytic properties of silver nanoparticles on the electrode surface, and electrodes were easily fabricated through the electrodeposition process. In addition, the surface shape, elemental properties, and HER activity of the electrode was analyzed by comparing it with the commercialized silver nanoparticle-coated invasive electrodes from Inanos (Inano-Ag-IE) through the plasma coating process. As a result, silver nanoparticle-coated conventional electrode (Ag-CE) fabricated through electrodeposition confirmed high HER activity and stability. However, the Inano-Ag-IE showed low HER activity as silver nanoparticles were not found. We encourage further research on the production process of such products for sustainable energy applications.

Synthesis and Characterization of Silver Nanoparticles from Psidium Guajava Leaf Extract

2021 ◽  
Vol 14 (5) ◽  
pp. 5634-5638
Author(s):  
Sruthi Radhakrishnan
Keyword(s):  
Silver Nanoparticles ◽  
Silver Nanoparticle ◽  
Leaf Extract ◽  
Nanoparticle Synthesis ◽  
Ethanolic Extract ◽  
Psidium Guajava ◽  
Sem Analysis ◽  
Synthesis Of Nanoparticles ◽  
Elemental Silver ◽  
Ft Ir

Green route for the synthesis of nanoparticles has become more acceptable than the other chemical as well as biological route. In the present study, silver nanoparticle is synthesized using ethanolic extract of Psidium guajava leaves. Further the synthesized silver nanoparticles were characterized by UV-Visible Spec, FT-IR, X-Ray Diffraction FESEM and E-DAX. The results of FT-IR provided evidence of the involvement of phytochemicals present in the leaf extract in the reduction of silver nitrate to silver nanoparticles. XRD confirmed the crystalline structure as well as shape of the synthesized nanoparticle as face-centred cubic. E-DAX profiling helped in determining the presence of elemental silver. The size of the nanoparticle procured by SEM analysis was found to be approximately 30-50 nm in size. Thus, the findings of this study showed that the plant assisted method for silver nanoparticle synthesis is more effective and further application level studies can shed lights on their use in healing of various human ailments.   

scholarly journals Silver nanoparticles with different size and shape: equal cytotoxicity, but different antibacterial effects

RSC Advances ◽  
2016 ◽  
Vol 6 (22) ◽  
pp. 18490-18501 ◽  
Author(s):  
J. Helmlinger ◽  
C. Sengstock ◽  
C. Groß-Heitfeld ◽  
C. Mayer ◽  
T. A. Schildhauer ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Silver Nanoparticle ◽  
Biological Effect ◽  
Dissolution Kinetics ◽  
Ultrapure Water ◽  
Antibacterial Effects ◽  
Size And Shape ◽  
Nanoparticle Morphology

The influence of silver nanoparticle morphology on their dissolution kinetics in ultrapure water as well as their biological effect on eukaryotic and prokaryotic cells was examined.

scholarly journals Antibacterial Effects of Erbium Chromium Laser along with/without Silver Nanoparticles in Root Canals Infected by Enterococcus faecalis

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Seyedeh Sareh Hendi ◽  
Negin Amiri ◽  
Banafsheh Poormoradi ◽  
Mohammad Yousef Alikhani ◽  
Saeid Afshar ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Enterococcus Faecalis ◽  
Sodium Hypochlorite ◽  
Silver Nanoparticle ◽  
Colony Count ◽  
Antibacterial Effects ◽  
Bacterial Colony ◽  
Root Canals ◽  
Significant Difference ◽  
Root Canal System

This study investigates the antibacterial effects of erbium chromium laser at 2780 nm, silver nanoparticles, and erbium chromium along with silver nanoparticles on Enterococcus faecalis in comparison with sodium hypochlorite. In the present study, 90 extracted human single-rooted teeth were selected and standardized to a length of 15 mm. The canals were prepared by V-taper Gold rotary files and then incubated with E. faecalis for 21 days. The samples were divided into four experimental groups including hypochlorite sodium, silver nanoparticle, erbium chromium laser, and erbium chromium laser along with silver nanoparticle groups. Results showed that there was a significant reduction in colony count for all groups after interventions. Moreover, there was a significant reduction in the colony count for sodium hypochlorite group in comparison with another groups, and this group showed the highest reduction of colony count. There was a significant difference between silver nanoparticles and erbium chromium laser groups in colony count. According to the results, the silver nanoparticles offered strong antibacterial effects on E. faecalis and therefore can decrease bacterial colonies, while the use of the laser, despite the reduction of the bacterial colony, could not be sufficiently used for disinfection of root canal system.

scholarly journals Protease-activatable biosensors of SARS-CoV-2 infection for cell-based drug, neutralisation and virological assays

2021 ◽  
Author(s):  
Pehuen Pereyra Gerber ◽  
Lidia M Duncan ◽  
Edward JD Greenwood ◽  
Sara Marelli ◽  
Adi Naamati ◽  
...  
Keyword(s):  
Fluorescent Protein ◽  
Firefly Luciferase ◽  
Neutralising Antibodies ◽  
Antiviral Therapies ◽  
Viral Proteases ◽  
Green Fluorescent ◽  
High Throughput Screens ◽  
Protease Expression ◽  
In Cells

The world is in the grip of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, and there is an urgent unmet clinical need for effective antiviral therapies. Many inhibitors of viral enzymes identified in vitro have limited efficacy against viral replication in cells, but conventional plaque assays are impractical for high-throughput screens. In this study, we therefore engineer cell-based biosensors of SARS-CoV-2 infection. Our assays exploit the cleavage of specific oligopeptide linkers by SARS-CoV-2 Main or Papain-like proteases, leading to the activation of green fluorescent protein (GFP) or firefly luciferase-based reporters. First, we characterise these biosensors in cells using recombinant viral proteases. Next, we confirm their ability to detect endogenous viral protease expression during infection with wildtype SARS-CoV-2. Finally, we develop a sensitive luminescent reporter cell line, confirm that it accurately quantitates infectious SARS-CoV-2 virus, and demonstrate its utility for drug screening and titration of neutralising antibodies.

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