NanoImpact ( IF 4.9 ) Pub Date : 2021-04-19 , DOI: 10.1016/j.impact.2021.100318 NicholasJ Niemuth 1 , Denise N Williams 2 , Arielle C Mensch 3 , Yi Cui 3 , Galya Orr 3 , Ze'ev Rosenzweig 2 , Rebecca D Klaper 1
Surface properties of engineered nanomaterials (ENMs) have been shown to influence their interaction with biological systems. However, studies to date have largely focused on hydrophilic materials, likely due to biocompatibility concerns and aqueous exposure conditions necessary for many model systems. Therefore, a knowledge gap exists in nanotoxicity literature for impacts of hydrophobic ENMs, with studies of hydrophobic materials largely limited to carbon ENMs. Here we demonstrate testing of hydrophobic quantum dots (QDs) using the nematode C. elegans, a model soil organism cultured on solid media and amenable to hydrophobic exposures. To evaluate the influence of hydrophobicity, we compared CdSe/ZnS QDs functionalized with hydrophobic trioctylphosphine oxide (TOPO) to identical QDs functionalized with hydrophilic dihydrolipoic acid-polyethylene glycol (DHLA-PEG) and alternative hydrophobic CdSe/ZnS QDs functionalized with oleic acid (OA). Results show that hydrophobic TOPO QDs are significantly more toxic than hydrophilic DHLA-PEG QDs, and substitution of TOPO with OA yields relatively non-toxic hydrophobic QDs. Fluorescence microscopy shows TOPO QDs loosely associated with the organism's cuticle, but atomic force microscopy shows no difference in cuticle structure from exposure. Importantly, TOPO ligand alone is as toxic as TOPO QDs, and our data suggests that TOPO may impact neuromuscular function, perhaps upon displacement from the QD surface. This study demonstrates the importance of examining ligand-specific impacts of hydrophobic ENMs and indicates OA-functionalized QDs as a potential alternative to TOPO QDs for reduced toxicity.
中文翻译:
疏水量子点的重新设计减轻了线虫中的配体依赖性毒性 C. elegans
工程纳米材料 (ENM) 的表面特性已被证明会影响它们与生物系统的相互作用。然而,迄今为止的研究主要集中在亲水性材料上,这可能是由于生物相容性问题和许多模型系统所需的水暴露条件。因此,纳米毒性文献中存在关于疏水性 ENM 影响的知识空白,对疏水性材料的研究主要限于碳 ENM。在这里,我们展示了使用线虫C. elegans测试疏水性量子点 (QD),一种在固体培养基上培养的模型土壤有机体,适合疏水暴露。为了评估疏水性的影响,我们将疏水性三辛基氧化膦 (TOPO) 功能化的 CdSe/ZnS 量子点与亲水性二氢硫辛酸-聚乙二醇 (DHLA-PEG) 功能化的相同量子点和油酸 (OA) 功能化的替代疏水 CdSe/ZnS 量子点进行了比较。 )。结果表明,疏水性 TOPO QDs 的毒性明显高于亲水性 DHLA-PEG QDs,并且用 OA 替代 TOPO 会产生相对无毒的疏水性 QDs。荧光显微镜显示 TOPO 量子点与生物体的角质层松散相关,但原子力显微镜显示暴露的角质层结构没有差异。重要的是,单独的 TOPO 配体与 TOPO 量子点一样有毒,我们的数据表明,TOPO 可能会影响神经肌肉功能,可能是在从 QD 表面移位时。这项研究证明了检查疏水 ENM 的配体特异性影响的重要性,并表明 OA 功能化 QD 作为 TOPO QD 的潜在替代品以降低毒性。