人工沉积物中四氧化三铁纳米颗粒对斑马鱼胚胎发育和氧化应激水平的影响

Effects of Fe_(3)O_(4)Nanoparticles on Development and Oxidative Stress in Zebrafish Embryo Exposed to Artificial Sediment

由于天然水体中合成的四氧化三铁纳米颗粒(Fe_(3)O_(4)NPs)含量未有可靠数据,因此就其安全阈值开展研究。本研究以模式动物斑马鱼为受试生物,将2 hpf的斑马鱼胚胎暴露在含有不同浓度Fe_(3)O_(4)NPs的沉积物中,96 hpf后考察其对斑马鱼胚胎发育和氧化应激水平的影响。结果显示,随着沉积物中Fe_(3)O_(4)NPs浓度的增加,斑马鱼胚胎及幼鱼的死亡率、畸形率呈现上升趋势,孵化率则呈现下降趋势。斑马鱼胚胎的死亡率、孵化率在0.8 mg·g^(-1)Fe_(3)O_(4)NPs的暴露下开始显著下降(P<0.05),畸形率则在0.4 mg·g^(-1)Fe_(3)O_(4)NPs暴露下开始显著上升(P<0.05)。96 hpf斑马鱼幼鱼体内活性氧(ROS)和丙二醛(MDA)含量随着沉积物中Fe_(3)O_(4)NPs浓度的增加而升高。超氧化物歧化酶(SOD)活性在1.6 mg·g^(-1)和3.2 mg·g^(-1)Fe_(3)O_(4)NPs暴露下显著下降(P<0.05),总抗氧化能力(T-AOC)在Fe_(3)O_(4)NPs最高浓度组(3.2 mg·g^(-1))显著下降(P<0.05)。随着沉积物中Fe_(3)O_(4)NPs浓度的增加,96 hpf的斑马鱼幼鱼体内Fe_(3)O_(4)NPs含量呈上升趋势,从0.4 mg·g^(-1)Fe_(3)O_(4)NPs开始与对照组相比具有显著差异(P<0.05)。因此,沉积物中Fe_(3)O_(4)NPs含量≤0.2 mg·g^(-1)是安全的,≥0.4 mg·g^(-1)是不安全的,沉积物中Fe_(3)O_(4)NPs的安全阈值范围是0.2~0.4 mg·g^(-1)。

Since there is no available analytical data for the content of synthesized Fe_(3)O_(4)nanoparticles(NPs)in natural water,the safety threshold was studied in this paper.A model animal zebrafish was used as the test organism,and 2 hpf zebrafish embryos were exposed to sediments containing different concentrations of Fe_(3)O_(4)NPs.After exposure until 96 hpf,the mortality and malformation rates of zebrafish embryos increased and the hatching rate decreased with the increase of Fe 3 O 4 NPs in the artificial sediment.Fe_(3)O_(4)NPs decreased the hatching rate of zebrafish embryos significantly(P<0.05)at the exposure concentration of 0.8 mg·g^(-1),and increased the malformation rates significantly(P<0.05)at 0.4 mg·g^(-1).With the increase of Fe_(3)O_(4)NPs content in sediment,the reactive oxygen species(ROS)and malondialdehyde(MDA)levels in zebrafish juvenile were increased,while the superoxide dismutase(SOD)activity was decreased at 1.6 mg·g^(-1)and 3.2 mg·g^(-1)(P<0.05).The total antioxidant capacity(T-AOC)reduced significantly in the highest concentration group(3.2 mg·g^(-1))(P<0.05).Iron accumulation in zebrafish showed an upward trend,and it was significantly higher at 0.4 mg·g^(-1)than that in the control group(P<0.05).The results indicate that it is safe for the content of Fe_(3)O_(4)NPs in sediments to be less than or equal to 0.2 mg·g^(-1),and higher than or equal to 0.4 mg·g^(-1)is unsafe.Therefore,the concentration range for the safety threshold of Fe_(3)O_(4)NPs in the sediment is from 0.2 mg·g^(-1)to 0.4 mg·g^(-1).