Toxicity of silver nanowires

A study suggests potential ways to reduce the toxicity of a nanotechnology component used in consumer electronics. Silver nanowires (AgNW) have broad potential applications in consumer electronics, but their chemical and physical properties suggest that they may be toxic to cells. Benjamin Gilbert and colleagues found that AgNW toxicity depends on the wires’ diameter. In cultured mouse and fish cells, wires approximately 10 microns in length and 30 nm in width were 1-2 orders of magnitude less toxic than 90-nm-wide wires of the same length. X-ray imaging of the cells revealed that the 30-nm wires adopted crumpled and collapsed forms inside cells and were completely contained within vesicles called endolysosomes. By contrast, 90-nm wires remained elongated after being engulfed by cells, with only the ends contained within endolysosomes. The results suggest that when cells engulf AgNW, membrane forces crumple sufficiently thin wires, facilitating containment within endolysosomes, whereas wires too thick to crumple puncture the endolysosome, leading to oxidative stress. In conductive transparent networks fabricated from AgNW, reducing the fiber diameter increased the optical transparency at a given low electrical resistivity. Thus, reducing nanowire diameter in consumer electronics could substantially reduce toxicity without compromising device performance, according to the authors.

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Article #18-20041: "Crumpling of silver nanowires by endolysosomes strongly reduces toxicity," by Sylvia G. Lehmann et al.

MEDIA CONTACT: Benjamin Gilbert, Lawrence Berkeley National Laboratory, Berkeley, CA; tel: 608-358-0194; e-mail: bgilbert@lbl.gov; Chris Vulpe, University of Florida, Gainesville, FL; tel: 650 291 5679; e-mail: cvulpe@ufl.edu; Laurent Charlet, Université Grenoble Alpes, FRANCE; tel: +33 6 75 87 82 66; e-mail: charlet38@gmail.com

Journal

Proceedings of the National Academy of Sciences