ABSTRACT
Nanotoxicity studies are greatly needed to advance nanomedical technologies into clinical practice. We assessed the toxic effects of a single intravenous exposure to commercially available gold nanoparticles (GNPs) in mice and rats. Fifteen-nm GNPs were purchased and independently characterized. Animals were exposed to either 1,000 mg GNPs/kg body weight (GNP group) or phosphate-buffered saline. Subsets of animals were euthanized and samples collected at 1, 7, 14, 21, and 28 days postexposure. Independent characterization demonstrated that the physicochemical properties of the purchased GNPs were in good agreement with the information provided by the supplier. Mice exposed to GNPs developed granulomas in the liver and transiently increased serum levels of the pro-inflammatory cytokine interleukin-18. No such alterations were found in rats. While there was no fatality in mice post-GNP exposure, a number of the rats died within hours of GNP administration. Differences in GNP biodistribution and excretion were also detected between the two species, with rats having a higher relative accumulation of GNPs in spleen and greater fecal excretion. In conclusion, GNPs have the ability to incite a robust macrophage response in mice, and there are important species-specific differences in their biodistribution, excretion, and potential for toxicity.
Subject(s)
Gold/toxicity , Metal Nanoparticles/toxicity , Animals , Female , Mice , Mice, Inbred BALB C , Rats , Rats, Inbred F344 , Species SpecificityABSTRACT
Low-frequency (<300â cm-1 ) vibrational interactions between gold surfaces and dissolved halides in water were investigated by surface-enhanced Raman spectroscopy (SERS). Experiments with NaF, NaCl, NaBr, and NaI salts indicate that the Raman shifts of the Au-X- SERS bands correlate with the bond strength of the corresponding covalent interaction. These low-frequency SERS bands open up new means to investigate the aggregation of nanoparticles in aqueous environments.
Subject(s)
Bromides/chemistry , Gold/chemistry , Metal Nanoparticles/chemistry , Sodium Chloride/chemistry , Sodium Compounds/chemistry , Sodium Fluoride/chemistry , Sodium Iodide/chemistry , Spectrum Analysis, Raman , Surface PropertiesABSTRACT
Gold-nanoparticles (AuNPs) are employed for cancer treatment, drug delivery, chemical analyses, and many other uses. As AuNP manufacture increases, it is imperative that we understand the environmental fate of these nanomaterials. We investigated the transport and stability of AuNPs under simulated groundwater conditions. Batch experiments indicated that 16 nm AuNPs stabilized with bovine serum albumin (BSA-cit-AuNPs) was slightly more stable under high ionic strength conditions than citrate-functionalized AuNPs (cit-AuNPs) of the same core size. Both types of AuNPs were injected into glass bead-packed columns and subjected to transport with varying NaCl and CaCl2 concentrations. BSA-cit-AuNPs deposited less than cit-AuNPs in the presence of increasing concentrations of CaCl2, but the opposite trend was observed in the presence of increasing concentrations of NaCl. This finding differed from the results obtained in the batch studies. Calculated attachment efficiencies (α) failed to reflect the observed experimental column data, with α at maximum only approaching 0.1 even though a majority of the AuNPs were retained in the column. Colloid filtration theory fails to predict and explain this discrepancy. We conclude that media induced nanoparticle aggregation is responsible for the inconsistency.
