Ellis Laura-Jayne A, Kissane Stephen, Hoffman Elijah, Brown James B, Valsami-Jones Eugenia, Colbourne John, Lynch Iseult
University of Birmingham, School of Geography, Earth and Environmental Sciences, Birmingham, B15 2TT, UK.
University of Birmingham, School of Biosciences, Birmingham, B15 2TT, UK.
Small. 2020 May;16(21):e2000301. doi: 10.1002/smll.202000301. Epub 2020 Apr 27.
Engineered nanoparticles (NPs) undergo physical, chemical, and biological transformation after environmental release, resulting in different properties of the "aged" versus "pristine" forms. While many studies have investigated the ecotoxicological effects of silver (Ag) NPs, the majority focus on "pristine" Ag NPs in simple exposure media, rather than investigating realistic environmental exposure scenarios with transformed NPs. Here, the effects of "pristine" and "aged" Ag NPs are systematically evaluated with different surface coatings on Daphnia magna over four generations, comparing continuous exposure versus parental only exposure to assess recovery potential for three generations. Biological endpoints including survival, growth and reproduction and genetic effects associated with Ag NP exposure are investigated. Parental exposure to "pristine" Ag NPs has an inhibitory effect on reproduction, inducing expression of antioxidant stress related genes and reducing survival. Pristine Ag NPs also induce morphological changes including tail losses and lipid accumulation associated with aging phenotypes in the heart, abdomen, and abdominal claw. These effects are epigenetic remaining two generations post-maternal exposure (F2 and F3). Exposure to identical Ag NPs (same concentrations) aged for 6 months in environmentally realistic water containing natural organic matter shows considerably reduced toxicological effects in continuously exposed generations and to the recovery generations.
工程纳米颗粒（NPs）在环境释放后会经历物理、化学和生物转化，导致“老化”形式与“原始”形式具有不同的特性。虽然许多研究调查了银（Ag）纳米颗粒的生态毒理学效应，但大多数研究集中在简单暴露介质中的“原始”Ag纳米颗粒，而不是研究转化后的纳米颗粒在实际环境暴露场景中的情况。在此，系统评估了“原始”和“老化”Ag纳米颗粒在四代大型溞上不同表面涂层的影响，比较了连续暴露与仅亲代暴露，以评估三代的恢复潜力。研究了与Ag纳米颗粒暴露相关的包括生存、生长和繁殖以及遗传效应在内的生物学终点。亲代暴露于“原始”Ag纳米颗粒对繁殖有抑制作用，诱导抗氧化应激相关基因的表达并降低生存率。原始Ag纳米颗粒还会诱导形态变化，包括尾部损失以及与心脏、腹部和腹爪衰老表型相关的脂质积累。这些效应是表观遗传的，在母代暴露后的两代（F2和F3）中仍然存在。在含有天然有机物的环境现实水体中老化6个月的相同Ag纳米颗粒（相同浓度）暴露，在连续暴露的几代和恢复代中显示出毒理学效应显著降低。
