A study published February 1, 2013 in the peer-reviewed scientific journal Toxicological Sciences finds silver nanoparticles to be toxic to the liver in vivo as well as toxic to hepatocytes in vitro (Gaiser et. al 2013). The researchers compared the toxicity of silver nanoparticles injected into lateral tail veins of rats to the effects of silver nanoparticles on human hepatocytes. In vitro silver nanoparticles caused lower release of the stress response hormone albumin in hepatocytes. While silver nanoparticles were membrane-bound in large agglomerates in vitro, the in vivo experiment showed them to be in smaller agglomerates, which were not membrane-bound and could be found both in the cytoplasm as well as in the nucleus. Inflammatory mediators remained below the limit of detection. The study concludes that decreased albumin production may be used as a marker of adverse effect of silver nanoparticles. The authors stress the need to examine low, non-cytotoxic, physiologically relevant doses in vitro, in order to draw conclusions for in vivo toxicity.
Gaiser, B.K., et al. (2013). "Effects of silver nanoparticles on the liver and hepatocytes in vitro." Toxicological Sciences 131:537-547.