U.S. Environmental Protection Agency, Office of Research and Development, Center for Public Health and Environmental Assessment, Public Health and Integrated Toxicology Division, Reproductive and Developmental Toxicology Branch, Research Triangle Park, Durham, NC, United States of America.
PLoS One. 2020 Dec 1;15(12):e0240268. doi: 10.1371/journal.pone.0240268. eCollection 2020.
During studies on the absorption and interactions between silver nanoparticles and mammalian cells grown in vitro it was observed that large extracellular rings of silver nanoparticles were deposited on the microscope slide, many located near post-mitotic cells. Silver nanoparticles (AgNP, 80nm), coated with citrate, were incubated at concentrations of 0.3 to 30 μg/ml with a human-derived culture of retinal pigment epithelial cells (ARPE-19) and observed using darkfield and fluorescent microscopy, 24 h after treatment. Approximately cell-sized extracellular rings of deposited AgNP were observed on the slides among a field of dispersed individual AgNP. The mean diameter of 45 nanoparticles circles was 62.5 +/-12 microns. Ring structures were frequently observed near what appeared to be post-mitotic daughter cells, giving rise to the possibility that cell membrane fragments were deposited on the slide during mitosis, and those fragments selectively attracted and retained silver nanoparticles from suspension in the cell culture medium. These circular structures were observable for the following technical reasons: 1) darkfield microscope could observe single nanoparticles below 100 nm in size, 2) a large concentration (108 and 109) of nanoparticles was used in these experiments 3) negatively charged nanoparticles were attracted to adhesion membrane proteins remaining on the slide from mitosis. The observation of silver nanoparticles attracted to apparent remnants of cellular mitosis could be a useful tool for the study of normal and abnormal mitosis.
在体外培养的哺乳动物细胞中研究银纳米粒子的吸收和相互作用时，观察到大量的银纳米粒子在显微镜载玻片上形成了细胞外大环，这些大环许多位于有丝分裂后细胞附近。用柠檬酸包覆的银纳米粒子（AgNP，80nm）以 0.3 至 30μg/ml 的浓度与源自人视网膜色素上皮细胞（ARPE-19）的培养物一起孵育，并在处理后 24 小时用暗场和荧光显微镜观察。在分散的单个 AgNP 场中，在载玻片上观察到大约与细胞大小相当的沉积 AgNP 的细胞外大环。45 个纳米粒子环的平均直径为 62.5 +/-12 微米。环结构经常在似乎是有丝分裂后子细胞附近观察到，这使得细胞膜片段在有丝分裂期间沉积在载玻片上，并且这些片段从细胞培养液中的悬浮中选择性地吸引和保留银纳米粒子成为可能。这些环状结构可以通过以下技术原因观察到：1）暗场显微镜可以观察到小于 100nm 的单个纳米粒子，2）在这些实验中使用了大量的纳米粒子（108 和 109），3）带负电荷的纳米粒子被吸引到有丝分裂后留在载玻片上的粘附膜蛋白上。观察到银纳米粒子被吸引到细胞有丝分裂的明显残留物上，这可能是研究正常和异常有丝分裂的有用工具。
