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Title: Autophagy induction by silver nanowires: A new aspect in the biocompatibility assessment of nanocomposite thin films

Abstract

Nanomaterials and their enabled products have increasingly been attracting global attention due to their unique physicochemical properties. Among these emerging products, silver nanowire (AgNW)-based thin films are being developed for their promising applications in next generation nanoelectronics and nanodevices. However, serious concerns remain about possible health and safety risks they may pose. Here, we employed a multi-modal systematic biocompatibility assessment of thin films incorporating AgNW. To represent the possible routes of nanomaterial entry during occupational or environmental exposure, we employed four different cell lines of epithelial, endothelial, gastric, and phagocytic origin. Utilizing a cell-based automated image acquisition and analysis procedure in combination with real-time impedance sensing, we observed a low level of cytotoxicity of AgNW, which was dependent on cell type, nanowire lengths, doses and incubation times. Similarly, no major cytotoxic effects were induced by AgNW-containing thin films, as detected by conventional cell viability and imaging assays. However, transmission electron microscopy and Western immunoblotting analysis revealed AgNW-induced autophasosome accumulation together with an upregulation of the autophagy marker protein LC3. Autophagy represents a crucial mechanism in maintaining cellular homeostasis, and our data for the first time demonstrate triggering of such mechanism by AgNW in human phagocytic cells. Finally, atomic force microscopymore » revealed significant changes in the topology of cells attaching and growing on these films as substrates. Our findings thus emphasize the necessity of comprehensive biohazard assessment of nanomaterials in modern applications and devices and a thorough analysis of risks associated with their possible contact with humans through occupational or environmental exposure. Highlights: ► Thin films containing nanomaterials are subject to increasing contact with humans. ► This study provides multi-modal biohazard assessment of AgNW-based thin films. ► Thin films containing AgNW affect human cell topology and attachment. ► AgNW toxicity depends on cell type, nanowire length, dose, and exposure time. ► AgNW can induce the process of autophagy in phagocytic cells.« less

Authors:
 [1];  [2];  [1]; ;  [3];  [1];  [4];  [1];  [1];  [2]
  1. Institute of Molecular Medicine, Trinity College Dublin (Ireland)
  2. (Ireland)
  3. Centre for Research on Adaptive Nanostructures and Nanodevices, Trinity College Dublin (Ireland)
  4. University of Massachusetts Medical School, Massachusetts (United States)
Publication Date:
OSTI Identifier:
22215966
Resource Type:
Journal Article
Journal Name:
Toxicology and Applied Pharmacology
Additional Journal Information:
Journal Volume: 264; Journal Issue: 3; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0041-008X
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; ATOMIC FORCE MICROSCOPY; DOSES; ENVIRONMENTAL EXPOSURE; HEALTH HAZARDS; HOMEOSTASIS; IMAGES; IMPEDANCE; QUANTUM WIRES; SILVER; THIN FILMS; TOXICITY; TRANSMISSION ELECTRON MICROSCOPY

Citation Formats

Verma, Navin K., Centre for Research on Adaptive Nanostructures and Nanodevices, Trinity College Dublin, Conroy, Jennifer, Lyons, Philip E., Coleman, Jonathan, O'Sullivan, Mary P., Kornfeld, Hardy, Kelleher, Dermot, Volkov, Yuri, E-mail: yvolkov@tcd.ie, and Centre for Research on Adaptive Nanostructures and Nanodevices, Trinity College Dublin. Autophagy induction by silver nanowires: A new aspect in the biocompatibility assessment of nanocomposite thin films. United States: N. p., 2012. Web. doi:10.1016/J.TAAP.2012.08.023.
Verma, Navin K., Centre for Research on Adaptive Nanostructures and Nanodevices, Trinity College Dublin, Conroy, Jennifer, Lyons, Philip E., Coleman, Jonathan, O'Sullivan, Mary P., Kornfeld, Hardy, Kelleher, Dermot, Volkov, Yuri, E-mail: yvolkov@tcd.ie, & Centre for Research on Adaptive Nanostructures and Nanodevices, Trinity College Dublin. Autophagy induction by silver nanowires: A new aspect in the biocompatibility assessment of nanocomposite thin films. United States. doi:10.1016/J.TAAP.2012.08.023.
Verma, Navin K., Centre for Research on Adaptive Nanostructures and Nanodevices, Trinity College Dublin, Conroy, Jennifer, Lyons, Philip E., Coleman, Jonathan, O'Sullivan, Mary P., Kornfeld, Hardy, Kelleher, Dermot, Volkov, Yuri, E-mail: yvolkov@tcd.ie, and Centre for Research on Adaptive Nanostructures and Nanodevices, Trinity College Dublin. Thu . "Autophagy induction by silver nanowires: A new aspect in the biocompatibility assessment of nanocomposite thin films". United States. doi:10.1016/J.TAAP.2012.08.023.
@article{osti_22215966,
title = {Autophagy induction by silver nanowires: A new aspect in the biocompatibility assessment of nanocomposite thin films},
author = {Verma, Navin K. and Centre for Research on Adaptive Nanostructures and Nanodevices, Trinity College Dublin and Conroy, Jennifer and Lyons, Philip E. and Coleman, Jonathan and O'Sullivan, Mary P. and Kornfeld, Hardy and Kelleher, Dermot and Volkov, Yuri, E-mail: yvolkov@tcd.ie and Centre for Research on Adaptive Nanostructures and Nanodevices, Trinity College Dublin},
abstractNote = {Nanomaterials and their enabled products have increasingly been attracting global attention due to their unique physicochemical properties. Among these emerging products, silver nanowire (AgNW)-based thin films are being developed for their promising applications in next generation nanoelectronics and nanodevices. However, serious concerns remain about possible health and safety risks they may pose. Here, we employed a multi-modal systematic biocompatibility assessment of thin films incorporating AgNW. To represent the possible routes of nanomaterial entry during occupational or environmental exposure, we employed four different cell lines of epithelial, endothelial, gastric, and phagocytic origin. Utilizing a cell-based automated image acquisition and analysis procedure in combination with real-time impedance sensing, we observed a low level of cytotoxicity of AgNW, which was dependent on cell type, nanowire lengths, doses and incubation times. Similarly, no major cytotoxic effects were induced by AgNW-containing thin films, as detected by conventional cell viability and imaging assays. However, transmission electron microscopy and Western immunoblotting analysis revealed AgNW-induced autophasosome accumulation together with an upregulation of the autophagy marker protein LC3. Autophagy represents a crucial mechanism in maintaining cellular homeostasis, and our data for the first time demonstrate triggering of such mechanism by AgNW in human phagocytic cells. Finally, atomic force microscopy revealed significant changes in the topology of cells attaching and growing on these films as substrates. Our findings thus emphasize the necessity of comprehensive biohazard assessment of nanomaterials in modern applications and devices and a thorough analysis of risks associated with their possible contact with humans through occupational or environmental exposure. Highlights: ► Thin films containing nanomaterials are subject to increasing contact with humans. ► This study provides multi-modal biohazard assessment of AgNW-based thin films. ► Thin films containing AgNW affect human cell topology and attachment. ► AgNW toxicity depends on cell type, nanowire length, dose, and exposure time. ► AgNW can induce the process of autophagy in phagocytic cells.},
doi = {10.1016/J.TAAP.2012.08.023},
journal = {Toxicology and Applied Pharmacology},
issn = {0041-008X},
number = 3,
volume = 264,
place = {United States},
year = {2012},
month = {11}
}