Article

Sulfidation of silver nanowires inside human alveolar epithelial cells: A potential detoxification mechanism

Department of Materials and London Centre for Nanotechnology, Imperial College London, Exhibition Road, London SW7 2AZ, UK. .
Nanoscale (Impact Factor: 7.39). 08/2013; 5(20). DOI: 10.1039/c3nr03205a
Source: PubMed

ABSTRACT Silver nanowires (AgNWs) are being developed for use in optoelectronics. However before widespread usage, it is crucial to determine their potential effects on human health. It is accepted that Ag nanoparticles (AgNPs) exert toxic effects by releasing Ag(+) ions, but much less is known about whether Ag(+) reacts with compounds, or any downstream bioactive effects of transformed AgNPs. Analytical high-resolution transmission electron microscopy has been employed to elucidate cellular uptake and reactivity of AgNWs inside human alveolar epithelial type 1-like cells. AgNWs were observed in the cytoplasm and membrane-bound vesicles, and precipitation of Ag2S within the cell occurred after 1 h exposure. Cell viability studies showed no evidence of cytotoxicity and reactive oxygen species were not observed on exposure of cells to AgNWs. We suggest that Ag2S formation acts as a 'trap' for free Ag(+), significantly limiting short-term toxicological effects - with important consequences for the safety of Ag-nanomaterials to human health.

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