Lehmann Sylvia G, Gilbert Benjamin, Maffeis Thierry Gg, Grichine Alexei, Pignot-Paintrand Isabelle, Clavaguera Simon, Rachidi Walid, Seve Michel, Charlet Laurent
Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IRD, IFSTTAR, ISTerre, 38000 Grenoble, France.
Energy Geoscience Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
Nanomaterials (Basel). 2018 Apr 11;8(4):232. doi: 10.3390/nano8040232.
Silver nanowires (AgNW) are attractive materials that are anticipated to be incorporated into numerous consumer products such as textiles, touchscreen display, and medical devices that could be in direct contact with skin. There are very few studies on the cellular toxicity of AgNW and no studies that have specifically evaluated the potential toxicity from dermal exposure. To address this question, we investigated the dermal toxicity after acute exposure of polymer-coated AgNW with two sizes using two models, human primary keratinocytes and human reconstructed epidermis. In keratinocytes, AgNW are rapidly and massively internalized inside cells leading to dose-dependent cytotoxicity that was not due to Ag⁺ release. Analysing our data with different dose metrics, we propose that the number of NW is the most appropriate dose-metric for studies of AgNW toxicity. In reconstructed epidermis, the results of a standard skin irritation assay classified AgNW as non-irritant to skin and we found no evidence of penetration into the deeper layer of the epidermis. The findings show that healthy and intact epidermis provides an effective barrier for AgNW, although the study does not address potential transport through follicles or injured skin. The combined cell and tissue model approach used here is likely to provide an important methodology for assessing the risks for skin exposure to AgNW from consumer products.
银纳米线（AgNW）是一种有吸引力的材料，预计将被纳入众多消费产品中，如纺织品、触摸屏显示器以及可能与皮肤直接接触的医疗设备。关于AgNW细胞毒性的研究非常少，且没有专门评估皮肤接触潜在毒性的研究。为了解决这个问题，我们使用人原代角质形成细胞和人重建表皮这两种模型，研究了两种尺寸的聚合物包覆AgNW急性暴露后的皮肤毒性。在角质形成细胞中，AgNW迅速大量内化进入细胞，导致剂量依赖性细胞毒性，这并非由于Ag⁺释放所致。用不同剂量指标分析我们的数据后，我们提出纳米线数量是研究AgNW毒性最合适的剂量指标。在重建表皮中，标准皮肤刺激性试验结果将AgNW归类为对皮肤无刺激性，并且我们没有发现其渗透到表皮深层的证据。研究结果表明，健康完整的表皮为AgNW提供了有效的屏障，尽管该研究未涉及通过毛囊或受损皮肤的潜在转运。这里使用的细胞和组织模型相结合的方法可能为评估消费品中AgNW皮肤暴露风险提供重要方法。
