View article

The present study aims at revealing the fate of 40-nm gold nanoparticles after intravenous injections. The gold nanoparticles were traced histochemically with light and transmission electron microscopy using autometallographic (AMG) staining, and the gold content in the liver was determined with inductively coupled plasma mass spectrometry (ICP-MS). Gold nanoparticles were identified in almost all Kupffer cells one day after the injection, but the fraction of gold-loaded cells gradually decreased to about one fifth after 6 months. Transmission electron microscopic analysis showed that the gold nanoparticles had accumulated inside the vesicular lysosome/endosome-like structures of the macrophages. At day 1, about 4.5‰ of the area of the liver sections was AMG-stained, after 1 month it had decreased to 0.7‰, and thereafter no further significant reduction was recorded. Because ICP-MS only showed a 9% fall in …