School of Freshwater Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA.
Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA.
Environ Toxicol Chem. 2023 Jul;42(7):1451-1462. doi: 10.1002/etc.5617. Epub 2023 May 17.
Complex metal oxide nanomaterials, like lithiated cobalt oxide (LCO) nanosheets, are among the most widespread classes of nanomaterials on the market. Their ubiquitous application in battery storage technology drives their production to rates of environmental significance without sufficient infrastructure for proper disposal/recycling, thus posing a risk to ecosystem health and sustainability. The present study assesses the general toxicological impacts of LCO when exposed to Raphidocelis subcapitata; physiological endpoints relating to growth and energy production are considered. Algal growth inhibition was significantly increased at concentrations as low as 0.1 µg ml , while exhibiting a median effect concentration of 0.057 µg ml . The average biovolume of cells was significantly enlarged at 0.01 µg ml , thus indicating increased instances of cell cycle arrest in LCO-treated cells. In addition, LCO-treated cells produced significantly less carbon biomass while significantly overproducing neutral lipid content starting at 0.1 µg ml , thus indicating interference with CO assimilation chemistry and/or carbon partitioning. However, the relative abundance of chlorophyll was significantly increased, likely to maximize light harvesting and compensate for photosynthetic interference. Cells that were treated with dissolved Li /Co ions did not significantly impact any of the endpoints tested, suggesting that LCO phytotoxicity is mainly induced through nano-specific mechanisms rather than ion-specific ones. These results indicate that this type of nanomaterial can significantly impact the way this alga proliferates, as well as the way it produces and stores its energy, even at lower, sublethal, concentrations. Furthermore, impairments to crucial cellular pathways, like carbon assimilation, could potentially cause implications at the ecosystem level. Thus, in future work, it will be important to characterize the molecular mechanisms of LCO at the nano-bio interface. Environ Toxicol Chem 2023;42:1451-1462. © 2023 SETAC.
复杂的金属氧化物纳米材料，如层状钴酸锂（LCO）纳米片，是市场上最广泛应用的纳米材料之一。由于其在电池储能技术中的广泛应用，其生产速度达到了具有环境意义的水平，但却没有足够的基础设施来进行适当的处置/回收，因此对生态系统健康和可持续性构成了风险。本研究评估了暴露于莱茵衣藻（Raphidocelis subcapitata）中的 LCO 的一般毒理影响；考虑了与生长和能量产生相关的生理终点。在浓度低至 0.1μg/ml 时，藻类生长抑制显著增加，而表现出的中值效应浓度为 0.057μg/ml。在 0.01μg/ml 时，细胞的平均生物体积显著增大，表明 LCO 处理细胞中的细胞周期停滞增加。此外，LCO 处理的细胞产生的碳生物量显著减少，而中性脂质含量显著增加，起始浓度为 0.1μg/ml，表明 CO 同化化学和/或碳分配受到干扰。然而，相对叶绿素含量显著增加，可能是为了最大限度地提高光捕获并补偿光合作用干扰。用溶解的 Li/Co 离子处理的细胞没有显著影响测试的任何终点，这表明 LCO 的植物毒性主要是通过纳米特异性机制而不是离子特异性机制引起的。这些结果表明，这种类型的纳米材料可以显著影响藻类的增殖方式，以及它产生和储存能量的方式，即使在较低的、亚致死的浓度下也是如此。此外，对关键细胞途径（如碳同化）的损害可能会对生态系统水平产生影响。因此，在未来的工作中，在纳米-生物界面表征 LCO 的分子机制将非常重要。Environ Toxicol Chem 2023;42:1451-1462. © 2023 SETAC.
