scholarly journals Silver Nanoparticles Surface-Modified with Carbosilane Dendrons as Carriers of Anticancer siRNA

2020 ◽  
Vol 21 (13) ◽  
pp. 4647 ◽  
Author(s):  
Elżbieta Pędziwiatr-Werbicka ◽  
Michał Gorzkiewicz ◽  
Katarzyna Horodecka ◽  
Viktar Abashkin ◽  
Barbara Klajnert-Maculewicz ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Silver Nanoparticles ◽  
Lymphocyte Proliferation ◽  
Intracellular Transport ◽  
Genetic Material ◽  
Hydrodynamic Diameter ◽  
Transmission Electron ◽  
The Stability ◽  
Surface Modified ◽  
Sites Of Action

Gene therapy is a promising approach in cancer treatment; however, current methods have a number of limitations mainly due to the difficulty in delivering therapeutic nucleic acids to their sites of action. The application of non-viral carriers based on nanomaterials aims at protecting genetic material from degradation and enabling its effective intracellular transport. We proposed the use of silver nanoparticles (AgNPs) surface-modified with carbosilane dendrons as carriers of anticancer siRNA (siBcl-xl). Using gel electrophoresis, zeta potential and hydrodynamic diameter measurements, as well as transmission electron microscopy, we characterized AgNP:siRNA complexes and demonstrated the stability of nucleic acid in complexes in the presence of RNase. Hemolytic properties of free silver nanoparticles and complexes, their effect on lymphocyte proliferation and cytotoxic activity on HeLa cells were also examined. Confocal microscopy proved the effective cellular uptake of complexes, indicating the possible use of this type of silver nanoparticles as carriers of genetic material in gene therapy.

scholarly journals SILVER NANOPARTICLES FROM MEDICINALLY IMPORTANT EUPHORBIA CYATHOPHORA EXTRACT: BIOSYNTHESIS, CHARACTERIZATION, AND ANTICANCER ACTIVITY.

2018 ◽  
Vol 11 (2) ◽  
pp. 154
Author(s):  
Robert Lotha ◽  
Aravind Sivasubramanian ◽  
Meenakshi Sundaram Muthuraman
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Cell Line ◽  
Aqueous Extract ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Transmission Electron ◽  
The Stability ◽  
Ht 29 ◽  
Scanning Electron

Objective: The present study was aimed at the biosynthesis of silver nanoparticles (AgNPs) using aqueous extract of Euphorbia cyathophora leavesand testing their anticancer potential using HT-29 cell line model.Methods: Green synthesis of silver nanoparticles was obtained with the aqueous extract of E. cyathophora. The synthesized nanoparticles wereconfirmed initially by ultraviolet-visible spectroscopy. Further, scanning electron microscopy, transmission electron microscopy, and X-Ray diffractionstudies also ensured the presence of silver nanoparticles. Zeta potential studies revealed the stability of the silver nanoparticles.Results: Antioxidant and anticancer studies of the nanoparticles against HT-29 cell line exhibited remarkable results.Conclusion: This ensures that the synthesized nanoparticles play an important role in medicinal biology.

scholarly journals Synthesis of Silver Nanoparticles using Egg White: Dye Degradation and Antimicrobial Potential

2021 ◽  
Vol 12 (2) ◽  
pp. 2361-2372
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Dye Degradation ◽  
Egg White ◽  
Blue Dye ◽  
Second Phase ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
The Stability ◽  
And Staphylococcus Aureus

In recent years, developing nanoparticles with green processes is gaining huge attention due to its cost-effectiveness, simplicity and non–toxic precursors. The present study utilized the potential of egg white for the synthesis of stable silver nanoparticles (EW-AgNPs). In order to characterize the EW-AgNPs, various techniques have been employed. UV-vis spectroscopy (300-700nm) was used to study the λmax, which highlighted the peak at 422nm. Further, the stability of synthesized EW-AgNPs was studied using Zeta potential, the value of -16.4 mV was obtained, indicating the stability of developed EW-AgNPs in the solution. Transmission electron microscopy was used specifically to visualize the shape and size of synthesized EW-AgNPs, the images showed spherical to the diverse shape of EW-AgNPs. In the first phase, the EW-AgNPs were studied for dye degradation along with NaBH4. The enhanced dye degradation of blue dye was obtained with EW-AgNPs+NaBH4, showing 90- 100% degradation from 100- 25 mgL-1 dye solution, respectively. Further, in the second phase, antimicrobial activity (Zone of Inhibition) of EW-AgNPs was analyzed against Escherichia coli and Staphylococcus aureus. A higher ZOI was obtained for E.coli (16mm) than S. aureus (12.4mm). The present study proved egg white's ability to develop stable silver nanoparticles, which was further found to be effective for blue dye degradation and antimicrobial activity.

scholarly journals In Vitro Antioxidant, Antitumor and Photocatalytic Activities of Silver Nanoparticles Synthesized Using Equisetum Species: A Green Approach

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7325
Author(s):  
Denisa Batir-Marin ◽  
Cornelia Mircea ◽  
Monica Boev ◽  
Ana Flavia Burlec ◽  
Andreia Corciova ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Photocatalytic Activity ◽  
Organic Dyes ◽  
Silver Ions ◽  
Green Approach ◽  
Transmission Electron ◽  
Biosynthesized Agnps ◽  
The Stability ◽  
Ld50 Value

The ethanolic extracts of three Equisetum species (E. pratense Ehrh., E. sylvaticum L. and E. telmateia Ehrh.) were used to reduce silver ions to silver nanoparticles (AgNPs). The synthesized AgNPs were characterized using UV-Vis spectrophotometry, Fourier Transform Infrared Spectroscopy (FTIR), Energy Dispersive X-ray (EDX), Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS) measurements. FTIR data revealed the functional groups of biomolecules involved in AgNPs synthesis, such as O-H, C-H, C=O, C-O, and C-C. EDX spectroscopy was used to highlight the presence of silver, while DLS spectroscopy provided information on the mean diameter of AgNPs, that ranged from 74.4 to 314 nm. The negative Zeta potential values (−23.76 for Ep–AgNPs, −29.54 for Es–AgNPs and −20.72 for Et–AgNPs) indicate the stability of the obtained colloidal solution. The study also focused on establishing the photocatalytic activity of AgNPs, which is an important aspect in terms of removing organic dyes from the environment. The best photocatalytic activity was observed for AgNPs obtained from E. telmateia, which degraded malachite green in a proportion of 97.9%. The antioxidant action of the three AgNPs samples was highlighted comparatively through four tests, with the best overall antioxidant capacity being observed for AgNPs obtained using E. sylvaticum. Moreover, the biosynthesized AgNPs showed promising cytotoxic efficacy against cancerous cell line MG63, the AgNPs obtained from E. sylvaticum L. providing the best result, with a LD50 value around 1.5 mg/mL.

scholarly journals Transformation and Cytotoxicity of Surface-Modified Silver Nanoparticles Undergoing Long-Term Aging

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2255 ◽  
Author(s):  
Chengfang Pang ◽  
Panhong Zhang ◽  
Yunsong Mu ◽  
Jingzheng Ren ◽  
Bin Zhao
Keyword(s):  
Silver Nanoparticles ◽  
Life Cycle ◽  
Aging Process ◽  
Consumer Products ◽  
Risk Assessments ◽  
The Stability ◽  
Surface Modified ◽  
Phosphate Buffered Saline ◽  
Shape Changes

Silver nanoparticles (AgNPs) are constituents of many consumer products, but the future of their production depends on ensuring safety. The stability of AgNPs in various physiological solutions and aging in storage may affect the accuracy of predicted nanoparticle toxicity. The goal of this study was to simulate the transformation of AgNPs in different media representatives to the life cycle in the environment and to identify their toxicity to Hepa1c1c7 cells in a long-term aging process. AgNPs coated with citrate, polyethylene glycol (PEG), polyvinylpyrrolidone (PVP), and branched polyethyleneimine (BPEI) were studied. Our results show that the exposure media had a significant impact on the transformation of AgNPs. Citrate-coated AgNPs showed significant aggregation in phosphate-buffered saline. The aging of AgNPs in optimal storage showed that the charge-stabilized particles (citrate) were more unstable, with significant aggregation and shape changes, than sterically stabilized particles (PEG AgNPs, PVP AgNPs). The BPEI AgNPs showed the highest dissolution of AgNPs, which induced significantly increased toxicity to Hepa1c1c7 cells. Overall, our findings showed that storage and media of AgNPs influenced the transformation of AgNPs and that the resulting changes in the AgNPs’ physicochemical properties influenced their toxicity. Our study contributes to the understanding of AgNPs’ transformations under realistic exposure scenarios and increasing the predictability of risk assessments.

scholarly journals Detection of Hg2+ Metal Ions Using Silver Nanoparticles Stabilized by Gelatin and Tween-20

2015 ◽  
Vol 15 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Lilis Sulistiawaty ◽  
Sri Sugiarti ◽  
Noviyan Darmawan
Keyword(s):  
Silver Nanoparticles ◽  
Metal Ions ◽  
Reduction Method ◽  
Limit Of Detection ◽  
Tween 20 ◽  
Color Changes ◽  
Transmission Electron ◽  
And Performance ◽  
The Stability ◽  
Average Size

Silver nanoparticles were synthesized by reduction method using glucose as reducing agent for precursor AgNO3. This research was aimed at comparing the stability and performance of silver nanoparticles with stabilizer gelatin (Gelatin-AgNPs) and tween-20 (Tween-AgNPs) produced from the synthesis to the silver nanoparticles without stabilizer, and applying the Gelatin-AgNPs and Tween-AgNPs to detect heavy metal in water sample. The silver nanoparticles produced were characterized using UV-Vis spectrophotometer and Transmission Electron Microscopy (TEM). From measurement of UV-Vis spectrophotometer, the absorbance wavelength of silver nanoparticles (AgNPs) appeared in range 411 nm, Gelatin-AgNPs in 417 nm, and Tween-AgNPs in 420 nm. The identification using TEM showed the average size for each AgNPs, Gelatin-AgNPs, and Tween-AgNPs was 11.73, 9.68, and 17.54 nm, respectively. The result showed that Gelatin-AgNPs has better stability compared to Tween-AgNPs. The reaction of Gelatin-AgNPs and Tween-AgNPs with several ions showed color changes of Gelatin-AgNPs and Tween-AgNPs occurred only on addition to Hg2+ metal ions solution. Based on the experiment of Hg2+ metal ions determination this method has limit of detection of 0.45 mg/L for Gelatin-AgNPs and 0.13 mg/L for Tween-AgNPs.

scholarly journals EFEITO DO Hg2+ E DOS ÍONS Cu2+, Fe2+, Ni2+, Sn2+ E Zn2+ NA ESTABILIDADE DE NANOPARTÍCULAS DE PRATA: UMA PRÁTICA INTERDISCIPLINAR DE NANOTECNOLOGIA EXPERIMENTAL

Química Nova ◽  
2020 ◽  
Author(s):  
Aline Katanosaka ◽  
Anne Fostier ◽  
Elias Santos
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Consumer Products ◽  
Chemistry Laboratory ◽  
Capping Agent ◽  
Colloid Stability ◽  
Interdisciplinary Practice ◽  
Transmission Electron ◽  
Upper Level ◽  
The Stability

EFFECT OF Hg2+ AND OF THE IONS Cu2+, Fe2+, Ni2+, Sn2+, AND Zn2+ ON THE STABILITY OF SILVER NANOPARTICLES: AN INTERDISCIPLINARY PRACTICE OF EXPERIMENTAL NANOTECHNOLOGY. The growing predominance of nanoscience and nanotechnology makes it increasingly important that these topics become an integral part of all scientific education. For this reason, in the present work, an interdisciplinary experiment of nanotechnology is introduced. As silver nanoparticles (AgNPs) are the most applied nanomaterial in consumer products, the current understanding of their stability is needed. Silver nanoparticles were synthesized using chitosan as a capping agent and a size distribution of 9.7 nm was determined by transmission electron microscopy. After preparation, the AgNPs colloid was divided into two parts. One part was stored in dark at 4.0 ± 1.0 o C and it was removed out from the fridge only to be analyzed by UV-vis. The second part was used to study the colloid stability in the presence of Hg2+, and also in the combination of mercury with the ions Cu2+, Fe2+, Ni2+, Sn2+, and Zn2+. The UV-vis analysis indicated that the AgNPs were oxidized in the presence of these ions, but in different intensities, which can be explained by using the electrochemistry approach. This work may be relevant for graduate-level or upper-level undergraduate experimental course preparation as the procedure is simple and easily reproducible in a typical chemistry laboratory.

The Influence of Ph on Green Synthesis of Honey-Mediated Silver Nanoparticles

2021 ◽  
Vol 891 ◽  
pp. 83-88
Author(s):  
Gusti Umindya Nur Tajalla ◽  
Mukhammad Arif Fakhruddin ◽  
Adinda Asmoro ◽  
Arif Basuki ◽  
Arie Wibowo
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Synthesis Method ◽  
Visual Observation ◽  
Hydrodynamic Diameter ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Ph Range ◽  
Influence Of Ph

Silver nanoparticles (AgNPs) have become interesting metal nanoparticles for filler composite electroactive bone scaffold due to its favorable electrical conductivity, chemical stability, and antibacterial activity. The green synthesis method was selected to produce AgNPs because of using safer solvents, minimizing dangerous reagents, and providing benign response conditions suitable for medical applications. In this study, AgNPs were prepared by a green synthesis approach using Indonesian wild honey with a wider pH range (5, 8, 11). Based on visual observation, UV-Vis spectroscopy, dynamic light scattering (DLS), and transmission electron microscopy (TEM) data, increasing pH leads to faster formation of AgNPs and smaller particle size of AgNPs. It was found that the smallest particle size of AgNPs (hydrodynamic diameter is 46.5 nm from DLS result and the actual particle size is 6.3 ± 1.5 nm from TEM result) was generated at pH 11.

scholarly journals Green Synthesis, Characterization, Enzyme Inhibition, Antimicrobial Potential, and Cytotoxic Activity of Plant Mediated Silver Nanoparticle Using Ricinus communis Leaf and Root Extracts

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 206
Author(s):  
Anadil Gul ◽  
Fozia ◽  
Asmat Shaheen ◽  
Ijaz Ahmad ◽  
Baharullah Khattak ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Ricinus Communis ◽  
Cost Effective ◽  
Synthesis Process ◽  
Ag Nps ◽  
Tem Analysis ◽  
Root Extracts ◽  
Transmission Electron ◽  
Mean Size ◽  
The Stability

The need of non-toxic synthesis protocols for nanoparticles arises developing interest in biogenic approaches. The present project was focused on cost effective, environment congenial synthesis of Ag nanoparticles and their biological applications. Leaf and root extracts of Ricinus communis were used as a reducing and stabilizing agent in synthesis process. A Proposed mechanism in published literature suggested that Indole-3-acetic acid, l-valine, triethyl citrate, and quercetin-3-0-p-d-glucopyranoside phytoconstituents of Ricinus communis act as reducing and capping agents. The synthesized Ag NPs were characterized with a help X-ray diffractometer, Transmission electron microscopy, UV-Vis spectrophotometry and Fourier Transform Infrared Spectroscopy (FTIR). The XRD results inveterate the synthesis of pure nano size crystalline silver particles. The FTIR data revealed the possible functional groups of biomolecules involved in bio reduction and capping for efficient stabilization of silver nanoparticles. TEM analysis confirmed the almost spherical morphology of synthesized particles with mean size 29 and 38 nm for R-Ag-NPs (root) and L-Ag-NPs (leaf), respectively. The stability of synthesized nanoparticles was examined against heat and pH. It was observed that synthesized nanoparticles were stable up to 100 °C temperature and also showed stability in neutral, basic and slightly acidic medium (pH 05–06) for several months while below pH 5 were unstable. The synthesized silver nanoparticles had promising inhibition efficiency in multiple applications, including as bactericidal/fungicidal agents and Urease/Xanthine oxidase enzymes inhibitors. The cytotoxicity of synthesized nanoparticles shows that the concentration under 20 μg/mL were biologically compatible.

TEM Analysis of Long-Period Polytypes in SiC—S

1976 ◽  
Vol 34 ◽  
pp. 630-631
Author(s):  
S. Shinozaki ◽  
J. W. Sprys
Keyword(s):  
Electron Diffraction ◽  
Isothermal Annealing ◽  
Tem Analysis ◽  
Long Period ◽  
Transmission Electron ◽  
Average Grain Size ◽  
High Resolution Tem ◽  
Structural Lattice ◽  
The Stability ◽  
Continuous Curves

In reaction sintered SiC (∽ 5um average grain size), about 15% of the grains were found to have long-period structures, which were identifiable by transmission electron microscopy (TEM). In order to investigate the stability of the long-period polytypes at high temperature, crystal structures as well as microstructural changes in the long-period polytypes were analyzed as a function of time in isothermal annealing.Each polytype was analyzed by two methods: (1) Electron diffraction, and (2) Electron micrograph analysis. Fig. 1 shows microdensitometer traces of ED patterns (continuous curves) and calculated intensities (vertical lines) along 10.l row for 6H and 84R (Ramsdell notation). Intensity distributions were calculated based on the Zhdanov notation of (33) for 6H and [ (33)3 (32)2 ]3 for 84R. Because of the dynamical effect in electron diffraction, the observed intensities do not exactly coincide with those intensities obtained by structure factor calculations. Fig. 2 shows the high resolution TEM micrographs, where the striped patterns correspond to direct resolution of the structural lattice periodicities of 6H and 84R structures and the spacings shown in the figures are as expected for those structures.

TEM characterization of Au/Polysilicon interactions

1990 ◽  
Vol 48 (4) ◽  
pp. 650-651
Author(s):  
N. David Theodore ◽  
Leslie H. Allen ◽  
C. Barry Carter ◽  
James W. Mayer
Keyword(s):  
Solid Phase ◽  
Single Crystal Silicon ◽  
Chemical Vapor ◽  
Electrical Contacts ◽  
Silicon Substrates ◽  
Crystal Silicon ◽  
Transmission Electron ◽  
Polysilicon Films ◽  
The Stability

Metal/polysilicon investigations contribute to an understanding of issues relevant to the stability of electrical contacts in semiconductor devices. These investigations also contribute to an understanding of Si lateral solid-phase epitactic growth. Metals such as Au, Al and Ag form eutectics with Si. reactions in these metal/polysilicon systems lead to the formation of large-grain silicon. Of these systems, the Al/polysilicon system has been most extensively studied. In this study, the behavior upon thermal annealing of Au/polysilicon bilayers is investigated using cross-section transmission electron microscopy (XTEM). The unique feature of this system is that silicon grain-growth occurs at particularly low temperatures ∽300°C).Gold/polysilicon bilayers were fabricated on thermally oxidized single-crystal silicon substrates. Lowpressure chemical vapor deposition (LPCVD) at 620°C was used to obtain 100 to 400 nm polysilicon films. The surface of the polysilicon was cleaned with a buffered hydrofluoric acid solution. Gold was then thermally evaporated onto the samples.

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