Antigenotoxic potential of boron nitride nanotubes

Boron and boron nitride nanotubes (BNNTs) are increasingly used in different industrial fields and, potentially, in some biomedical areas. As occurs with other nanomaterials (NMs), to increase our knowledge on their potential health hazards is a priority. Although <i>in vitro</i> approaches are a routine in getting biological information on the biological effects of NMs, the use of simple <i>in vivo</i> model organisms is receiving an increased interest. In this context, <i>Drosophila melanogaster</i> is widely used as a eukaryotic model for the study of the potential harmful effects associated with various agents, including NMs. The aim of this study is to provide new data on the potential antioxidant/antigenotoxic properties of boron and boron nitride nanotubes (BNNTs), as well as on other biological end-points. Our results show changes in the expression of genes involved in the antioxidant defense (<i>CAT</i> and <i>SOD</i>), and in those rel0061ted to the integrity of the intestinal barrier (<i>Duox</i>, <i>Hml</i>, <i>Muc68D</i>, and <i>PPO2</i>), at the highest exposure doses (5, 10 mM). However, non-relevant toxic or genotoxic effects were observed. Interestingly, BNNTs and boron significantly reduced the genotoxic effect of potassium dichromate (PDC), and the intracellular levels of reactive oxygen species (ROS). This suggest that the observed effects can be linked to the antioxidant properties of BNNTs and boron. This is the first study reporting antigenotoxicity/genotoxicity, and gene expression data, in the somatic cells of <i>D. melanogaster</i> larvae for BNNTs.

硼及氮化硼纳米管（boron nitride nanotubes, BNNTs）正日益广泛应用于各类工业领域，同时在部分生物医学领域具备潜在应用价值。与其他纳米材料（nanomaterials, NMs）一样，深入阐明其潜在健康危害是当前的研究重点。尽管体外实验（in vitro）方法是获取纳米材料生物效应相关生物学信息的常规手段，但简单体内模式生物的应用正受到越来越多的关注。在此背景下，黑腹果蝇（Drosophila melanogaster）作为经典真核模式生物，被广泛用于研究各类因子（包括纳米材料）相关的潜在有害效应。本研究旨在为硼及氮化硼纳米管（BNNTs）的潜在抗氧化/抗遗传毒性特性，以及其他生物学终点提供全新实验数据。在最高暴露剂量（5、10 mM）下，研究结果显示，参与抗氧化防御的基因（CAT、SOD）以及与肠道屏障完整性相关的基因（Duox、Hml、Muc68D及PPO2）的表达水平发生显著变化。然而，本研究未观测到与暴露相关的毒性或遗传毒性效应。值得注意的是，氮化硼纳米管与硼可显著降低重铬酸钾（potassium dichromate, PDC）诱导的遗传毒性效应，同时下调细胞内活性氧（reactive oxygen species, ROS）水平。这表明观测到的生物学效应可归因于氮化硼纳米管与硼的抗氧化特性。本研究是首个针对氮化硼纳米管，在黑腹果蝇（D. melanogaster）幼虫体细胞中报道其抗遗传毒性/遗传毒性效应及基因表达数据的相关研究。