Department of Chemical and Biomolecular Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore.
Nanoscale. 2018 Apr 26;10(16):7726-7735. doi: 10.1039/c7nr05975b.
Silver nanoparticles (AgNPs) are widely incorporated into commercial products due to their antimicrobial properties. As a consequence, concerns about the adverse effects induced by AgNPs to humans and the environment need to be carefully examined. The existing literature reveals that AgNPs exhibit certain toxic effects, but it remains to be proved whether AgNPs or the ionic silver (Ag+) released from AgNPs are the main toxic species. Here, a genetically encoded fluorescent protein sensor with high affinity to Ag+ was developed. The resulting sensor, MT2a-FRET, was found to be ratiometric, sensitive and selective toward only Ag+ but inert against AgNPs. This makes this sensor a potential useful tool for monitoring the real-time intracellular dissolutions of AgNPs. Our data supported that AgNPs display the "Trojan-horse" mechanism, where AgNPs are internalized by cells and undergo dissolution intracellularly. We further found that cells exhibited a detoxification ability to remove active Ag+ from cells in 48 hours.
由于具有抗菌性能，纳米银颗粒（AgNPs）被广泛应用于商业产品中。因此，需要仔细研究 AgNPs 对人类和环境产生的不良影响。现有文献表明，AgNPs 具有一定的毒性作用，但仍需证明是 AgNPs 还是 AgNPs 释放的离子银（Ag+）是主要的毒性物质。在这里，开发了一种对 Ag+具有高亲和力的基因编码荧光蛋白传感器。结果表明，该传感器 MT2a-FRET 呈比率型，对 Ag+敏感且具有选择性，但对 AgNPs 不敏感。这使得该传感器成为监测 AgNPs 实时细胞内溶解的潜在有用工具。我们的数据支持 AgNPs 表现出“特洛伊木马”机制，AgNPs 被细胞内化并在细胞内发生溶解。我们还发现，细胞在 48 小时内表现出解毒能力，可将活性 Ag+从细胞中去除。
