Study of interaction of ethylene glycol/PVP phase on noble metal powders prepared by polyol process

Bonet, F.; Tekaia-Elhsissen, K.; Sarathy, K. Vijaya

doi:10.1007/bf02719903

Cited by 143 publications

(90 citation statements)

References 9 publications

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“…1D), indicating the coordination of N atom of PVP with Ag NPs, a result consistent with previous reports. 45,46 Ag NPs induce autophagosome accumulation…”

Section: Synthesis and Characterization Of Silver Nanoparticlesmentioning

confidence: 99%

Inhibition of autophagy enhances the anticancer activity of silver nanoparticles

et al. 2014

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Abbreviations: ANXA5, annexin A5; CASP3, caspase 3, apoptosis-related cysteine peptidase; CTSB, cathepsin B; DLS, dynamic light scattering; DMEM, Dulbecco's Modified Eagle's medium; EGFP-LC3, enhanced green fluorescent protein-tagged LC3; ICP-MS, inductively coupled plasma-mass spectrometry; I-MEF, immortalized mouse embryonic fibroblast; MDC, monodansylcadaverine; MTOR, mechanistic target of rapamycin; P-MEF, primary mouse embryonic fibroblast; PI, propidium iodide; PI3K, phosphoinositide 3-kinase; PtdIns3K, phosphatidylinositol 3-kinase; PVP, polyvinylpyrrolidone; RPS6KB, ribosomal protein S6 kinase, 70 kDa; s.c., subcutaneously; SQSTM1, sequestosome 1; TEM, transmission electron microscopy; TUNEL, terminal deoxyribonucleotidyl transferase (TDT)-mediated dUTPdigoxigenin nick end labeling; UV-Vis, ultraviolet visible; XRD, X-ray diffraction.Silver nanoparticles (Ag NPs) are cytotoxic to cancer cells and possess excellent potential as an antitumor agent. A variety of nanoparticles have been shown to induce autophagy, a critical cellular degradation process, and the elevated autophagy in most of these situations promotes cell death. Whether Ag NPs can induce autophagy and how it might affect the anticancer activity of Ag NPs has not been reported. Here we show that Ag NPs induced autophagy in cancer cells by activating the PtdIns3K signaling pathway. The autophagy induced by Ag NPs was characterized by enhanced autophagosome formation, normal cargo degradation, and no disruption of lysosomal function. Consistent with these properties, the autophagy induced by Ag NPs promoted cell survival, as inhibition of autophagy by either chemical inhibitors or ATG5 siRNA enhanced Ag NPs-elicited cancer cell killing. We further demonstrated that wortmannin, a widely used inhibitor of autophagy, significantly enhanced the antitumor effect of Ag NPs in the B16 mouse melanoma cell model. Our results revealed a novel biological activity of Ag NPs in inducing cytoprotective autophagy, and inhibition of autophagy may be a useful strategy for improving the efficacy of Ag NPs in anticancer therapy.

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“…1D), indicating the coordination of N atom of PVP with Ag NPs, a result consistent with previous reports. 45,46 Ag NPs induce autophagosome accumulation…”

Section: Synthesis and Characterization Of Silver Nanoparticlesmentioning

confidence: 99%

Inhibition of autophagy enhances the anticancer activity of silver nanoparticles

et al. 2014

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“…One possible function for PVP was to kinetically control the growth rates of various faces by interacting with these faces through adsorption and desorption. 20 The slow dissolution of the small silver particles into the solution might also play a certain role in achieving an anisotropic growth for the large silver particles. In principle, this growth process would continue until all silver particles with diameters <5 nm had been completely consumed ( Figures 1C and 1D).…”

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confidence: 99%

Crystalline Silver Nanowires by Soft Solution Processing

et al. 2002

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This paper describes a soft, solution-phase approach to the large-scale synthesis of uniform nanowires of bicrystalline silver whose lateral dimensions could be controlled in the range of 30−40 nm, and lengths up to ∼50 µm. The first step of this procedure involved the formation of platinum nanoparticles by reducing PtCl 2 with ethylene glycol heated to ∼160°C. Due to their close match in crystal structure and lattice constants, these platinum nanoparticles could serve as seeds for the heterogeneous nucleation and growth of silver that was produced in the solution via the reduction of AgNO 3 with ethylene glycol. When surfactants such as poly(vinyl pyrrolidone) (PVP) were present in this solution, the silver could be directed to grow into uniform nanowires with aspect ratios as high as ∼1000. Measurements of transport property at room temperature indicated that these nanowires were electrically continuous with a conductivity of approximately 0.8 × 10 5 S/cm.One-dimensional (1D) nanostructures of metals play an important role as both interconnects and active components in fabricating nanoscale electronic devices.1 They also provide an ideal model system to experimentally investigate physical phenomena such as quantized conductance and localization effects. 2 Silver nanowires with well-defined dimensions are particularly interesting to synthesize and study because bulk silver exhibits the highest electrical (or thermal) conductivity among all metals. Silver has also been used in a rich variety of commercial applications, and the performance of silver in these applications could be potentially enhanced by processing silver into 1D nanostructures with well-controlled dimensions and aspect ratios. For instance, the loading of silver in a polymeric composite could be significantly reduced when nanoparticles of silver are replaced by nanowires having higher aspect ratios. 3 A number of chemical approaches have been actively explored to process silver into 1D nanostructures. For example, silver nanowires have been synthesized by reducing AgNO 3 with a developer in the presence of AgBr nanocrystallites, 4 or by arc discharging between two silver electrodes immersed in an aqueous NaNO 3 solution. 5 Silver nanorods have been produced by irradiating an aqueous AgNO 3 solution with ultraviolet light in the presence of poly-(vinyl alcohol). 6 The final products of all these methods are, however, characterized by problems such as low yields, irregular morphologies, polycrystallinity, and low aspect ratios. In contrast, the template-directed synthesis offers a better controlled route to 1D silver nanostructures. 14 Here we wish to report a soft (with temperatures <200°C), solution-phase approach that allows for the production of bicrystalline nanowires of silver with uniform diameters and in bulk quantities.The first step of our synthesis involved the formation of Pt nanoparticles by reducing PtCl 2 with ethylene glycol refluxed at ∼160°C.15 In this so-called polyol process, ethylene glycol served as both solvent and re...

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“…In the presence of a surface modifier, the reaction changes depending on the ability of the metal to coordinate with it, as in the case of PVP where the metallic precursor could coordinate with the oxygen of the pyrrolidone group, when the particles are in the nanometer size range, while when they are in the micrometer size range the coordination is mainly with the nitrogen, as reported by F. Bonet et al [Sun, Y. et al, 2002;Bonet, F. et al, 2000] By the polyol method with ethylene glycol as solvent-reductor, was possible to obtain monometallic platinum and palladium Nps with narrow size distributions in systems with small particles (2-4 nm) and different structures depending on the temperature of reaction. The structure of platinum and palladium Nps are cubic, face centered.…”

Section: Resultsmentioning

confidence: 88%

Deposition and Characterization of Platinum and Palladium Nanoparticles on Highly Oriented Pyrolytic Graphite

Elizondo¹,

Galván²,

Álvarez‐Contreras³

et al. 2012

The Transmission Electron Microscope

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Study of interaction of ethylene glycol/PVP phase on noble metal powders prepared by polyol process

Cited by 143 publications

References 9 publications

Inhibition of autophagy enhances the anticancer activity of silver nanoparticles

Inhibition of autophagy enhances the anticancer activity of silver nanoparticles

Crystalline Silver Nanowires by Soft Solution Processing

Deposition and Characterization of Platinum and Palladium Nanoparticles on Highly Oriented Pyrolytic Graphite

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