Document Type
Article
Publication Date
2014
Publication Source
ACS Nano
Abstract
In view of the vast number of new nanomaterials (NMs) that require testing and the constraints associated with animal models, the majority of studies to elucidate nanotoxicological effects have occurred in vitro, with limited correlation and applicability to in vivo systems and realistic, occupational exposure scenarios.
In this study, we developed and implemented a chronic in vitromodel coupled with lower, regulatory dosages in order to provide a more realistic assessment of NM-dependent consequences and illuminate the implications of long-term NM exposure. When keratinocytes were exposed to 50 nm silver nanoparticles (Ag-NPs), we determined that chronically dosed cells operated under augmented stress and modified functionality in comparison to their acute counterparts.
Specifically, Ag-NP exposure through a chronic mechanism increased p38 activation, actin disorganization, heightened ki67 expression, and extensive gene modification. Additionally, chronic Ag-NP exposure altered the way in which cells perceived and responded to epidermal growth factor stimulation, indicating a transformation of cell functionality. Most importantly, this study demonstrated that chronic exposure in the pg/mL range to Ag-NPs did not induce a cytotoxic response, but instead activated sustained stress and signaling responses, suggesting that cells are able to cope with prolonged, low levels of Ag-NP exposure.
In summary, we demonstrated that through implementation of a chronic dosimetry paradigm, which more closely resembles realistic NM exposure scenarios, it is possible to illuminate long-term cellular consequences, which greatly differ from previously obtained acute assessments.
Inclusive pages
3260–3271
ISBN/ISSN
1936-0851
Document Version
Postprint
Copyright
Copyright © 2014, American Chemical Society
Publisher
American Chemical Society
Volume
8
Peer Reviewed
yes
Issue
4
eCommons Citation
Comfort, Kristen K.; Braydich-Stolle, Laura K.; Maurer, Elizabeth I.; and Hussain, Saber M., "Less Is More: Long-Term in Vitro Exposure to Low Levels of Silver Nanoparticles Provides New Insights for Nanomaterial Evaluation" (2014). Chemical and Materials Engineering Faculty Publications. 172.
https://ecommons.udayton.edu/cme_fac_pub/172
Included in
Other Chemical Engineering Commons, Other Materials Science and Engineering Commons, Petroleum Engineering Commons, Polymer and Organic Materials Commons, Thermodynamics Commons
Comments
This document is the authors' accepted manuscript, provided for download in compliance with the publisher's policy on self-archiving. Some differences may exist between this document and the version of record.
Permission documentation is on file.