Scientific Article - An In Vivo Time-Exposure Investigation

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

exposures.

 

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

cytokines.

 

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

warranted.