Toxicology Section, National Institute for Occupational Health, Johannesburg, South Africa; School of Pathology, University of the Witwatersrand, Johannesburg, South Africa.
Toxicol Appl Pharmacol. 2019 Jan 15;363:131-141. doi: 10.1016/j.taap.2018.11.014. Epub 2018 Dec 5.
Physico-chemical characteristics of nanoparticles have been shown to alter the uptake and toxicity of nanoparticles. This study investigated the uptake of six gold nanoparticles (AuNPs) into the human bronchial epithelial cell line BEAS-2B. The AuNPs studied included colloidal citrate-stabilised AuNPs of 14 nm in diameter; and 14 nm AuNPs conjugated to functional groups via polyethylene glycol (PEG), namely hydroxyl-PEG (POH), carboxyl-PEG (PCOOH), biotin-PEG (PBtn), nitrilotriacetic acid-PEG (PNTA), and azide-PEG (PAZ). Uptake was visualised by dark field microscopy using the CytoViva Hyperspectral Imaging system and after a 2 hour incubation at 37 °C, uptake was observed in cells treated with the citrate-stabilised and PCOOH AuNPs. However, no uptake was observed for the POH, PBtn, PNTA, or PAZ AuNPs, even after 24 h of incubation. An investigation into the energy dependence of uptake of the citrate-stabilised and PCOOH AuNPs showed that uptake was an active process. Cells pre-treated with either chlorpromazine or genistein as endocytosis inhibitors for clathrin- and caveolae-mediated pathways respectively, prior to addition of AuNPs, suggested a caveolae-dependent mechanism of endocytosis. These results further support recent findings on the mechanism of intracellular uptake and localisation and the subsequent toxicity of nanoparticles.
纳米粒子的物理化学特性已被证明会改变纳米粒子的摄取和毒性。本研究调查了六种金纳米粒子（AuNPs）进入人支气管上皮细胞系 BEAS-2B 的摄取情况。所研究的 AuNPs 包括直径为 14nm 的胶体柠檬酸盐稳定的 AuNPs；以及通过聚乙二醇（PEG）与官能团偶联的 14nm AuNPs，即羟基-PEG（POH）、羧基-PEG（PCOOH）、生物素-PEG（PBtn）、氮川三乙酸-PEG（PNTA）和叠氮-PEG（PAZ）。通过使用 CytoViva 高光谱成像系统的暗场显微镜观察摄取情况，在 37°C 孵育 2 小时后，在用柠檬酸盐稳定的和 PCOOH AuNPs 处理的细胞中观察到摄取。然而，在用 POH、PBtn、PNTA 或 PAZ AuNPs 孵育 24 小时后，没有观察到摄取。对柠檬酸盐稳定的和 PCOOH AuNPs 摄取的能量依赖性的研究表明，摄取是一个主动过程。在用氯丙嗪或染料木黄酮预处理细胞之前，作为网格蛋白和小窝介导途径的内吞作用抑制剂，然后加入 AuNPs，表明存在小窝依赖的内吞作用机制。这些结果进一步支持了关于纳米粒子细胞内摄取和定位以及随后毒性的机制的最新发现。
