Quantification of Intraperitoneally Injected Silver Nanoparticles in Regionally Dissected Brains and Secondary Organs of Mice using Graphite Furnace Atomic Absorption Spectroscopy

Silver nanoparticles (AgNPs) have become increasingly prevalent in consumer and medical products, textiles, and packaging due to their antimicrobial properties. As a result of their relatively small size (with dimensions less than 100 nm), nanoparticles have the ability to cross the blood brain barrier and cellular membranes in both humans and many experimental organisms, including mice. AgNPs thus potentially have cyotoxic, genotoxic, and behavioral effects on exposed organisms. Previous literature has explored where AgNPs build up systemically, but to date no studies have evaluated how AgNPs distribute regionally within the brain. In this study, experimental mice were intraperitoneally injected for 14 days, not including weekends, with either 10 or 15 mg/kg AgNPs. AgNPs were quantified via graphite furnace atomic absorption spectroscopy (GFAAS) in brain tissue (hippocampus, cerebellum, cortex, and striatum), secondary organs (liver, spleen, kidney, and remaining un-dissected brain), and feces. There was no difference between the control and experimental groups within the brain regions studied. However, the kidneys, spleen, and remaining un-dissected brain did show significant accumulation of Ag, although the liver did not. Lastly, the feces collected over four timepoints contained a significant amount of Ag, indicating that the biliary excretion pathway is a possible mechanism for removal of Ag from systemic circulation