Biological safety and tissue distribution of (16-mercaptohexadecyl) trimethylammonium bromide-modified cationic gold nanorods

The exceptionally high cellular uptake of gold nanorods (GNRs) bearing cationic surfactants makes them a promising tool for biomedical applications. Given the known specific toxic and stress effects of some preparations of cationic nanoparticles, the purpose of this study was to evaluate, in an in vitro and in vivo in mouse, the potential harmful effects of GNRs coated with (16-mercaptohexadecyl)trimethylammo-nium bromide ((MTAB)GNRs). Interestingly, even after cellular accumulation of high amounts of (MTAB)GNRs sufficient for induction of photothermal effect, no genotoxicity (even after longer-term accumulation), induction of autophagy, destabilization of lysosomes (dominant organelles of their cellular destination), alterations of actin cytoskeleton, or in cell migration could be detected in vitro. In vivo, after intravenous administration, the majority of GNRs accumulated in mouse spleen followed by lungs and liver. Microscopic examination of the blood and spleen showed that GNRs interacted with white blood cells (mononuclear and polymorphonuclear leukocytes) and thrombocytes, arid were delivered to the spleen red pulp mainly as GNR-thrombocyte complexes. Importantly, no acute toxic effects of (MTAB)GNRs administered as 10 or 50 mu g of gold per mice, as well as no pathological changes after their high accumulation in the spleen were observed, indicating good tolerance of (MTAB)GNRs by living systems. (c) 2017 Elsevier Ltd. Ail rights reserved