Choi Yoojin, Kim Hyun-A, Kim Kyoung-Woong, Lee Byung-Tae
Department of Chemical and Biomolecular Engineering (BK21 Plus Program), Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea.
J Environ Sci (China). 2018 Apr;66:50-60. doi: 10.1016/j.jes.2017.04.028. Epub 2017 May 9.
With the increase in silver (Ag)-based products in our lives, it is essential to test the potential toxicity of silver nanoparticles (AgNPs) and silver ions (Ag ions) on living organisms under various conditions. Here, we investigated the toxicity of AgNPs with Ag ions to Escherichia coli K-12 strain under various conditions. We observed that both AgNPs and Ag ions display antibacterial activities, and that Ag ions had higher toxicity to E. coli K-12 strain than AgNPs under the same concentrations. To understand the toxicity of AgNPs at a cellular level, reactive oxygen species (ROS) enzymes were detected for use as antioxidant enzymatic biomarkers. We have also studied the toxicity of AgNPs and Ag ions under various coexistence conditions including: fixed total concentration, with a varied the ratio of AgNPs to Ag ions; fixed the AgNPs concentration and then increased the Ag ions concentration; fixed Ag ions concentration and then increasing the AgNPs concentration. Exposure to AgNPs and Ag ions clearly had synergistic toxicity; however, decreased toxicity (for a fixed AgNPs concentration of 5mg/L, after increasing the Ag ions concentration) to E. coli K-12 strain. AgNPs and Ag ions in the presence of L-cysteine accelerated the bacterial cell growth rate, thereby reducing the bioavailability of Ag ions released from AgNPs under the single and coexistence conditions. Further works are needed to consider this potential for AgNPs and Ag ions toxicity across a range of environmental conditions.
As silver nanoparticles (AgNPs)-based products are being broadly used in commercial industries, an ecotoxicological understanding of the AgNPs being released into the environment should be further considered. Here, we investigate the comparative toxicity of AgNPs and silver ions (Ag ions) to Escherichia coli K-12 strain, a representative ecotoxicological bioreporter. This study showed that toxicities of AgNPs and Ag ions to E. coli K-12 strain display different relationships when existing individually or when coexisting, and in the presence of L-cysteine materials. These findings suggest that the toxicology research of nanomaterials should consider conditions when NPs coexist with and without their bioavailable ions.
随着我们生活中银（Ag）基产品的增加，在各种条件下测试银纳米颗粒（AgNPs）和银离子（Ag离子）对生物体的潜在毒性至关重要。在此，我们研究了AgNPs与Ag离子在各种条件下对大肠杆菌K - 12菌株的毒性。我们观察到AgNPs和Ag离子均具有抗菌活性，并且在相同浓度下，Ag离子对大肠杆菌K - 12菌株的毒性高于AgNPs。为了在细胞水平上理解AgNPs的毒性，检测了活性氧（ROS）酶作为抗氧化酶生物标志物。我们还研究了AgNPs和Ag离子在各种共存条件下的毒性，包括：固定总浓度，改变AgNPs与Ag离子的比例；固定AgNPs浓度，然后增加Ag离子浓度；固定Ag离子浓度，然后增加AgNPs浓度。暴露于AgNPs和Ag离子显然具有协同毒性；然而，对大肠杆菌K - 12菌株的毒性降低（对于固定的5mg/L AgNPs浓度，增加Ag离子浓度后）。在L - 半胱氨酸存在下，AgNPs和Ag离子加速了细菌细胞生长速率，从而降低了在单一和共存条件下从AgNPs释放的Ag离子的生物利用度。需要进一步开展工作来考虑AgNPs和Ag离子在一系列环境条件下的这种潜在毒性。
由于基于银纳米颗粒（AgNPs）的产品正在广泛应用于商业行业，应进一步考虑对释放到环境中的AgNPs的生态毒理学理解。在此，我们研究了AgNPs和银离子（Ag离子）对大肠杆菌K - 12菌株（一种代表性的生态毒理学生物报告物）的比较毒性。这项研究表明，AgNPs和Ag离子对大肠杆菌K - 12菌株的毒性在单独存在或共存以及存在L - 半胱氨酸材料时表现出不同的关系。这些发现表明，纳米材料的毒理学研究应考虑纳米颗粒与其生物可利用离子共存和不共存时的条件。
