TY - JOUR
T1 - Protein corona-induced modification of silver nanoparticle aggregation in simulated gastric fluid
AU - Ault, Andrew P.
AU - Stark, Diana I.
AU - Axson, Jessica L.
AU - Keeney, Justin N.
AU - Maynard, Andrew
AU - Bergin, Ingrid L.
AU - Philbert, Martin A.
N1 - Funding Information:
This project was supported through National Institute of Health Grant U01ES020128. Silver nanoparticles used in this study where procured, characterized, and provided to investigators by NIEHS Center for Nanotechnology Health Implications Research (NCNHIR) Consortium. D. I. S. was supported by the National Institute of Environmental Health Sciences under Award Number T32ES007062. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. The University of Michigan Center for Materials Characterization (MC) in the College of Engineering is acknowledged for use of the JEOL 3011 High Resolution Electron Microscope (NSF Grant #DMR-0315633). The Biophysics Department at the University of Michigan is acknowledged for use of the Jasco CD-spectropolarimeter.
Publisher Copyright:
© The Royal Society of Chemistry 2016.
PY - 2016
Y1 - 2016
N2 - Due to their widespread incorporation into a range of biomedical and consumer products, the ingestion of silver nanoparticles (AgNPs) is of considerable concern to human health. However, the extent to which AgNPs will be modified within the gastric compartment of the gastrointestinal tract is still poorly understood. Studies have yet to fully evaluate the extent of physicochemical changes to AgNPs in the presence of biological macromolecules, such as pepsin, the most abundant protein in the stomach, or the influence of AgNPs on protein structure and activity. Herein, AgNPs of two different sizes and surface coatings (20 and 110 nm, citrate or polyvinylpyrrolidone) were added to simulated gastric fluid (SGF) with or without porcine pepsin at three pHs (2.0, 3.5, and 5.0), representing a range of values between preprandial (fasted) and postprandial (fed) conditions. Rapid increases in diameter were observed for all AgNPs, with a greater increase in diameter in the presence of pepsin, indicating that pepsin facilitated aggregation of AgNPs. AgNPs interactions with pepsin only minimally reduced the protein's proteolytic functioning capability, with the greatest inhibitory effect caused by smaller (20 nm) particles of both coatings. No changes in pepsin secondary structural elements were observed for the different AgNPs, even at high particle concentrations. This research highlights the size-dependent kinetics of nanoparticle aggregation or dissolution from interaction with biological elements such as proteins in the gastrointestinal tract. Further, these results demonstrate that, in addition to mass, knowing the chemical form and aggregation state of nanoparticles is critical when evaluating toxicological effects from nanoparticle exposure in the body.
AB - Due to their widespread incorporation into a range of biomedical and consumer products, the ingestion of silver nanoparticles (AgNPs) is of considerable concern to human health. However, the extent to which AgNPs will be modified within the gastric compartment of the gastrointestinal tract is still poorly understood. Studies have yet to fully evaluate the extent of physicochemical changes to AgNPs in the presence of biological macromolecules, such as pepsin, the most abundant protein in the stomach, or the influence of AgNPs on protein structure and activity. Herein, AgNPs of two different sizes and surface coatings (20 and 110 nm, citrate or polyvinylpyrrolidone) were added to simulated gastric fluid (SGF) with or without porcine pepsin at three pHs (2.0, 3.5, and 5.0), representing a range of values between preprandial (fasted) and postprandial (fed) conditions. Rapid increases in diameter were observed for all AgNPs, with a greater increase in diameter in the presence of pepsin, indicating that pepsin facilitated aggregation of AgNPs. AgNPs interactions with pepsin only minimally reduced the protein's proteolytic functioning capability, with the greatest inhibitory effect caused by smaller (20 nm) particles of both coatings. No changes in pepsin secondary structural elements were observed for the different AgNPs, even at high particle concentrations. This research highlights the size-dependent kinetics of nanoparticle aggregation or dissolution from interaction with biological elements such as proteins in the gastrointestinal tract. Further, these results demonstrate that, in addition to mass, knowing the chemical form and aggregation state of nanoparticles is critical when evaluating toxicological effects from nanoparticle exposure in the body.
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U2 - 10.1039/c6en00278a
DO - 10.1039/c6en00278a
M3 - Article
AN - SCOPUS:85000762774
SN - 2051-8153
VL - 3
SP - 1510
EP - 1520
JO - Environmental Science: Nano
JF - Environmental Science: Nano
IS - 6
ER -