Studies have focused on nanoparticle (NP) fate and toxicity, with limited information on the physiological environment's role in altering NP physical properties. Artificial fluids (AFs) have been used to test bioavailability of metallic compounds, which is the difference between the amount of substance a person is exposed to and the actual amount the body receives. Literature has demonstrated inhaled NPs accumulated in lungs and clearance was hindered during chronic exposure indicating effects should become more pronounced over time. This study examined the impact of artificial interstitial, alveolar, lysosomal, and gastric fluid on hydrocarbon silver (Ag-HC) and polysaccharide silver (Ag-PS) NPs and the associated changes in toxicity. Since inhalation exposure is of concern, the toxicity was evaluated in alveolar macrophages and doses represent a week or year of exposure (0.5 ng/ml/25 ng/ml) based on the concept that delayed clearance will result in continual macrophage recruitment to engulf the NPs. For all the AFs, the Ag-HC NPs demonstrated agglomeration, limited ionic dissociation, and no toxicity. Ag-PS NPs exposed to alveolar and interstitial fluid demonstrated a similar trend, in addition to a loss of PS coating. For the gastric fluid, agglomerates were observed but these were rare and due to the Ag NPs precipitating out as AgCl. Interestingly, the Ag-PS NPs exposed to lysosomal fluid demonstrated a loss of coating, less agglomeration, and significant toxicity. Since NPs are taken up via endocytosis, the interactions of the NP with the lysosomal environment has critical implications on mediating the NP cellular consequences. Based on this study, the lysosomal environment has the potential to make a NP more toxic over time. (88ABW-2012-5185)

Bioavailability of silver nanoparticles in artificial physiological fluids: Coating and pH impact on degree of ionic dissociation

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.