Research regarding exposure and toxicity of nanomaterials (NMs) to humans has been widely studied over the past two decades and whether engineered NMs produce adverse outcomes/responses when exposed to various microorganisms, tissues, and cells. However, the majority of research conducted on the topic has failed to consider how the immediate local environment and usage scenario impact the physical and chemical properties of NMs and how those alterations impact exposure. The current research presented utilizes silver nanoparticles (AgNPs) as a case study for how the immediate local environment alters the physical and chemical properties of NMs. The primary route for exposure to many of the consumer products containing AgNPs would occur dermally, thus nanosilver exposure in these cases must take into account interactions such as that between human sweat and AgNPs. This interaction represents an important local environment that could alter NM speciation and the specific chemical/material that individuals would be exposed to. Presently, several studies have examined Ag release from AgNP-containing products (primarily textiles) after exposure to artificial sweat. However, there is seemingly no basic assessment of how perspiration alters the physical and chemical properties of AgNPs in a simple mixture with artificial sweat.  In the current study, we utilized four different formulations of artificial sweat (0.9% sodium chloride, acidic and basic sweat according to the International Organization for Standardization, and acidic sweat as defined by the American Association of Textile Chemists and Colorists). The solutions were mixed with AgNP dispersions at two concentration ratios. Samples were collected at 4 time intervals for further analysis using dynamic light scattering (DLS), UV-Vis spectroscopy, and single particle inductively coupled plasma-mass spectrometry (spICP-MS). For the water-only stock solutions, DLS and spICP-MS both present an increase in equivalent size over the time series, but the UV-Vis peak was invariant, suggesting physical aggregation. With the artificial sweat mixtures, results were much more inconsistent but do indicate that changes are directly related to the composition of the artificial perspiration. Additionally, each mixture was centrifuged using 3 kDa filters to assess changes in physicochemical properties using ICP-MS, X-ray absorption fine spectroscopy, and scanning electron microscopy coupled to energy-dispersive X-ray analysis.

Assessing the interaction of silver nanoparticles with various artificial sweat formulations

256th National Meeting (2018)

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