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Uptake and toxic effects of surface modified nanomaterials in freshwater aquatic organisms.

机译：表面改性纳米材料在淡水水生生物中的吸收和毒性作用。

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摘要

Nanomaterials are a class of materials with unique properties due to their size, and the association of these properties with the toxicity of nanomaterials is poorly understood. The present study assessed the toxic effects of stable aqueous colloidal suspensions of three distinctly different classes of nanomaterials in aquatic organisms. The fullerene, C70, was stabilized through non-covalent surface modification with gallic acid. Toxicity of C70-gallic acid was confirmed to exhibit similar toxic effects as C60-fullerene, including changes in antioxidative processes in Daphnia magna. Daphnia magna fecundity was significantly reduced in 21d bioassays at C70-gallic concentrations below quantifiable limits (0.03 mg/L C70). Antioxidant enzyme activities of glutathione peroxidase and superoxide dismutase as well as lipid peroxidation suggested that exposed organisms experienced oxidative stress.;Carbon dots are a class of nanomaterials proposed for use as nontoxic alternatives to semiconductor quantum dots for photoluminescent applications, because of the difference in toxicity of their core components: carbon as opposed to heavy metals. In vivo analysis of treated organisms by confocal fluorescence microscopy revealed carbon dots were absorbed and systemically distributed regardless of particle size. The present study did not find any evidence of acute toxicity at concentrations up to 10mg/L carbon dots. These concentrations also failed to produce negative effects in Ceriodaphnia dubia bioassays to predict chronic toxicity. Carbon dots also failed to elicit developmental toxic effects in zebrafish.;The toxic effects of semiconductor quantum dots have been partially attributed to the release of heavy metals with their degradation, particularly cadmium. Laser ablation inductively coupled mass spectrometry was used to compare the uptake of cadmium, selenium and zinc in Daphnia magna treated to CdSe/ZnS quantum dots or CdCl2. These quantum dots were observed to accumulate primarily in the gut lumen and no evidence of uptake of intact quantum dots was observed. Evidence suggests degradation of the quantum dots release of component ions with accumulation of Cd and Zn in the gut epithelia. Quantum dots elicited acute toxicity at 0.66 mg/L Cd but promoted increased reproduction at 40 microg/L.
机译：纳米材料是一类由于其尺寸而具有独特性能的材料，人们对这些性能与纳米材料毒性之间的联系了解甚少。本研究评估了三种明显不同类别的纳米材料在水生生物中稳定的水性胶体悬浮液的毒性作用。通过用没食子酸的非共价表面改性来稳定富勒烯C70。证实C70-没食子酸的毒性表现出与C60-富勒烯类似的毒性作用，包括大型蚤中抗氧化过程的变化。在低于可量化限值（0.03 mg / L C70）的C70-大蒜浓度下，第21天生物测定中的大型蚤（Daphnia magna）的繁殖力显着降低。谷胱甘肽过氧化物酶和超氧化物歧化酶的抗氧化酶活性以及脂质过氧化表明暴露的生物体经历了氧化应激。碳点是一类纳米材料，由于毒性的不同，被提议用作光致发光应用的半导体量子点的无毒替代品。它们的核心成分：碳，而不是重金属。通过共聚焦荧光显微镜对处理过的生物进行体内分析表明，无论颗粒大小如何，碳点均被吸收并系统分布。本研究未发现任何浓度高达10mg / L碳点的急性毒性证据。这些浓度也未能在杜鹃花生物测定法中产生不利影响以预测慢性毒性。碳点也未能引起斑马鱼的发育毒性作用。半导体量子点的毒性作用部分归因于重金属的释放及其降解，特别是镉的释放。激光烧蚀电感耦合质谱法用于比较处理CdSe / ZnS量子点或CdCl2处理的水蚤中镉，硒和锌的吸收。观察到这些量子点主要聚集在肠腔中，没有观察到完整量子点被摄取的迹象。有证据表明随着肠道上皮中镉和锌的积累，组分离子的量子点释放变差。量子点在0.66 mg / L Cd时引起急性毒性，但在40 microg / L时促进繁殖增加。

著录项

  • 作者

    Seda, Brandon Casey.;

  • 作者单位

    Clemson University.;

  • 授予单位 Clemson University.;
  • 学科 Health Sciences Toxicology.;Engineering Materials Science.
  • 学位 Ph.D.
  • 年度 2012
  • 页码 120 p.
  • 总页数 120
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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