AN IN VIVO HUMAN TIME-EXPOSURE INVESTIGATION OF
A COMMERCIAL SILVER NANO-PARTICLE SOLUTION. M. A.
M. A. Munger, P. Radwanski, G. J. Stoddard, A. Shaaban, D. Grainger, G.Yost
University of Utah, SLC, UT.
BACKGROUND:,The biodistribution, bioprocessing and possible toxicity of silver
nanoparticles is receiving increasing attention in human health through greater
METHODS:,To understand whether these concerns are justified, we prospectively
studied 3-, 7-, and 14-day exposures to an American Biotech Laboratory 10-ppm
(15 ml/day) silver solution in a doubleblind, controlled, cross-over phase design.
Healthy volunteer subjects (36, 12 each time-exposure), underwent complete
metabolic, blood and platelet count, urinalysis tests, sputum hyperresponsiveness
and inflammation evaluation, physical examinations, vital sign measurements,
and magnetic resonance imaging of the chest and abdomen at baseline and end
of each phase. Diet was not controlled. Silver serum and urine quantization was
determined by inductively coupled plasma mass spectrometry (NMS Labs).
Significance in individual laboratory values was determined by any value being 2 x
ULN or 4 SD from the mean and by clinical judgment. Mixed effects linear and
logistic regression models compared the mean effect to the normal reference
range control limits. MRI morphology changes were qualitatively described.
RESULTS:,No clinically important changes in any metabolic, hematologic, or
urinalysis measure identified were determined. No morphological (or structural)
changes were detected in the lungs, heart (cardiac function) or abdominal organs.
No changes were noted in sputum reactive oxygen species or in pro-inflammatory
CONCLUSION:,In'vivo oral exposure of a commercial 10-ppm silver nano-particle
solution over 3-, 7-, and 14-day exposures does not exhibit clinically important
changes in metabolic, hematologic, urine, vital sign changes, physical findings or
imaging changes visualized by MRI. Further study of increasing time-exposure,
dose, and additional organ systems, including cytochrome P-450 enzymes, is