School of Environment, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Henan Normal University, Xinxiang 453007, China.
School of Environment, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Henan Normal University, Xinxiang 453007, China.
J Hazard Mater. 2024 Mar 5;465:133204. doi: 10.1016/j.jhazmat.2023.133204. Epub 2023 Dec 12.
Hexagonal boron nitride (h-BN) nanomaterials have attracted numerous attentions for application in various fields, including environmental governance. Understanding the environmental implications of h-BN is a prerequisite for its safe and sustainable use; nevertheless, information on the negative effect of h-BN on aquatic organisms and the underlying toxicity mechanisms is scarce. The present study found that low exposure doses (0.1-1 μg/mL) of micron-sized h-BN lamella apparently suppressed (maximally 45.3%) the growth of Chlorella vulgaris (a freshwater alga) via membrane damages and metabolic reprogramming. Experimental and simulation results verified that h-BN can penetrate into and then extract phospholipids from the cell membrane of algae due to the strong hydrophobic interactions between h-BN nanosheets and lipids, resulting in membrane permeabilization and integrity reduction. Oxidative stress-triggered lipid peroxidation also contributes to membrane destruction of algae. Metabolomics assay demonstrated that h-BN down-regulated the CO-fixation associated Calvin cycle and glycolysis/gluconeogenesis pathways in algae, thereby inhibiting energy synthesis and antioxidation process. Despite releasing soluble B inside cells, the B species exhibited negligible toxicity. These findings highlight the phenomena and mechanisms of h-BN toxicity in photosynthetic algae, which have great implications for guiding their safe use under the scenarios of global carbon neutrality.
六方氮化硼（h-BN）纳米材料因其在各个领域（包括环境治理）的应用而备受关注。了解 h-BN 对环境的影响是其安全和可持续利用的前提；然而，关于 h-BN 对水生生物的负面影响及其潜在毒性机制的信息却很少。本研究发现，低暴露剂量（0.1-1μg/mL）的微米级 h-BN 薄片明显通过膜损伤和代谢重编程来抑制（最大 45.3%）淡水藻类小球藻的生长。实验和模拟结果证实，由于 h-BN 纳米片与脂质之间的强疏水相互作用，h-BN 可以穿透并从藻类细胞膜中提取脂质，导致膜通透性增加和完整性降低。氧化应激引发的脂质过氧化也有助于藻类细胞膜的破坏。代谢组学分析表明，h-BN 下调了藻类中与 CO2 固定相关的卡尔文循环和糖酵解/糖异生途径，从而抑制了能量合成和抗氧化过程。尽管细胞内释放了可溶性 B，但 B 物种的毒性可以忽略不计。这些发现强调了 h-BN 在光合作用藻类中的毒性现象和机制，这对于指导在全球碳中和情景下安全使用 h-BN 具有重要意义。
