Whole-body retention and distribution of orally administered radiolabelled zerovalent iron nanoparticles in mice

Abstract

Zerovalent iron nanoparticles (nZVI) are used for in situ remediation of contaminated ground water, raising the possibility that nZVI particles or their altered residues could contaminate the ground water. Therefore, it is important to study their effects on humans and other organisms in vivo. The objective of this study was to assess the whole-body retention and terminal disposition of neutron-activated radioactive nZVI administered by oral gavage in mice. Radioactivity was primarily eliminated in the faeces within 1 day of administration. However, a small amount of iron-derived radioactivity appeared in the liver after three repeated daily doses. This prototypic study further suggests that neutron activation applied judiciously may be broadly applicable to studies of nanoparticles derived from other biologically abundant metals.

Keywords::

• Nanoparticles
• iron
• neutron activation
• disposition
• nZVI

Acknowledgments

This manuscript has been reviewed by the National Health and Environmental Effects Research Laboratory of the US Environmental Protection Agency (EPA) and approved for publication. Approval does not signify that the contents necessarily reflect the views of the Agency, nor does the mention of trade names or commercial products constitute endorsement or recommendation for use. This work was funded entirely by the US EPA. The authors would like to thank Scott Lassell, Manager, Nuclear Services, Nuclear Reactor Program of North Carolina State University for critically valuable help and advice and Dr. Bellina Veronesi of the US EPA for her advice and for providing the nanoparticles used in the study. The authors appreciate the able assistance of Brenda Edwards with animal dosing and critical comments by EPA colleagues Drs. Kevin Dreher, David Thomas and Jane Ellen Simmons.