Environmental Biogeochemistry and Ecotoxicology, Institute F.-A. Forel, Earth and Environmental Sciences, Faculty of Sciences, University of Geneva, 10 route de Suisse, 1290 Versoix, Switzerland; Laboratory of Environmental Toxicology, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn, Estonia.
Laboratory of Environmental Toxicology, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn, Estonia.
Environ Pollut. 2014 Jul;190:58-64. doi: 10.1016/j.envpol.2014.03.021. Epub 2014 Apr 13.
Protozoa as phagocytizing cells have been shown to integrate engineered nanoparticles (NPs), while the mechanism, dynamics and extent of such uptake are unclear. Here our fluorescence microscopy data showed that CdSe/ZnS quantum dots (QDs) with primary size of 12 nm were readily phagocytized into the food vacuoles of Tetrahymena thermophila in a time- and dose-dependent manner. Twenty hours after the exposure to QDs in sublethal concentration the clearance of the QDs from the cells was incomplete suggesting that phagocytosis of QDs into food vacuoles was not the only pathway of uptake by T. thermophila. This was further proven by the results that the inhibition of phagocytosis did not block the internalization of QDs into protozoans. This study provides a new insight into uptake and cellular trafficking of subtoxic concentrations of nanoparticles that may, due to prolonged retention times in the cells, pose risks by potentially becoming available to higher trophic levels.
已经证明，原生动物作为吞噬细胞可以整合工程纳米颗粒（NPs），而这种摄取的机制、动力学和程度尚不清楚。在这里，我们的荧光显微镜数据显示，粒径为 12nm 的 CdSe/ZnS 量子点（QDs）可以在时间和剂量依赖的方式下被原生动物四膜虫的食物泡轻易吞噬。在亚致死浓度的 QDs 暴露 20 小时后，细胞内 QDs 的清除不完全，这表明 QDs 被吞噬到食物泡中不是四膜虫摄取 QDs 的唯一途径。这一结果进一步证明，吞噬作用的抑制并不能阻止 QDs 进入原生动物体内。这项研究为亚毒性浓度的纳米颗粒的摄取和细胞内转运提供了新的见解，由于这些纳米颗粒在细胞内的滞留时间延长，它们可能会通过潜在地进入更高的营养级而带来风险。
