Oceanographic Institute, University of São Paulo, São Paulo, Brazil.
Oceanographic Institute, University of São Paulo, São Paulo, Brazil.
Mutat Res Genet Toxicol Environ Mutagen. 2022 Sep;881:503527. doi: 10.1016/j.mrgentox.2022.503527. Epub 2022 Jul 9.
Silver nanoparticles (AgNP) are widely used in several applications including as antifouling agents; therefore, they can end up in estuarine and marine environments. These nanoparticles tend to aggregate and to deposit in the sediment, where many organisms feed and reproduce. Parhyale hawaiensis is an epibenthic amphipod globally distributed in tropical zones, and has been considered a potential model for ecotoxicology. The aim of this study was to evaluate genotoxic effects of AgNP and Ag salt via feeding, as P. hawaiensis lives in the sediment where nanoparticles tend to accumulate. Organisms were cultivated in the laboratory, and adults were exposed to food containing both AgNP and Ag salt. We collected hemolymph after different times of exposure, and analysed the hemocytes for nuclear abnormalities (including micronuclei) and DNA damage using the standard alkaline comet assay. Conditions of both assays were developed/optimized to allow their successful application in marine invertebrates. Increased frequencies of micronuclei, nuclear buds and total abnormalities were detected in relation to concentration and time in organisms exposed to AgNP and Ag salt in comparison to the controls. No DNA damage was detected when the alkaline comet assay was applied. After 5 days of exposure, we observed higher micronuclei frequencies in Ag salt treatment in comparison with AgNP. After 13 days, micronuclei frequencies were similar for both silver forms. We believe that the Ag, in its ion form, is causing the mutagenic effect; therefore, more time would be needed for the release of the ion from AgNP, explaining the delayed mutagenic effect.
银纳米粒子（AgNP）广泛应用于多种领域，包括作为防污剂；因此，它们可能最终会出现在河口和海洋环境中。这些纳米粒子往往会聚集并沉积在沉积物中，许多生物在那里觅食和繁殖。Parhyale hawaiensis 是一种全球性分布在热带地区的底栖桡足类动物，已被认为是生态毒理学的潜在模型。本研究旨在通过摄食评估 AgNP 和 Ag 盐的遗传毒性，因为 P. hawaiensis 生活在纳米粒子容易聚集的沉积物中。生物在实验室中进行培养，成年个体暴露于含有 AgNP 和 Ag 盐的食物中。我们在不同的暴露时间后收集血淋巴，并使用标准碱性彗星试验分析血细胞中的核异常（包括微核）和 DNA 损伤。为了能够成功应用于海洋无脊椎动物，我们开发/优化了这两种试验的条件。与对照组相比，暴露于 AgNP 和 Ag 盐的生物中，微核、核芽和总异常的频率随着浓度和时间的增加而增加。当应用碱性彗星试验时，未检测到 DNA 损伤。在 5 天的暴露后，我们观察到 Ag 盐处理中的微核频率高于 AgNP。13 天后，两种银形态的微核频率相似。我们认为，Ag 以离子形式引起致突变作用；因此，需要更多的时间从 AgNP 释放离子，这解释了延迟的致突变作用。
