Division of Toxicology, Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, Laurel, MD 20708, USA,
Int J Nanomedicine. 2018 Dec 12;13:8365-8378. doi: 10.2147/IJN.S174184. eCollection 2018.
Nanoparticles exhibit unique physiochemical characteristics that provide the basis for their utilization. The diversity of potential and actual applications compels a thorough understanding regarding the consequences of their containment within the cellular environment.
This paper presents a flow cytometric examination of the biologic effects associated with the internalization of citrate-buffered silver (Ag) nanoparticles (NP) by the murine macrophage cell line, RAW264.7.
Cells were cultured with varying concentrations of citrate-buffered Ag nanoparticle and analyzed for changes in cellular volume, fluorescence emissions, and surface receptor expression.
Notable changes in side scatter (SSC) signal occurred following the phagocytosis of citrate-buffered Ag NP representative of the 10 nm, 50 nm, and 100 nm particle size by cultured RAW 264.7 cells. A characteristic associated with the internalization of all the citrated Ag NP sizes tested, was the detection of emitted infra-red and near-infrared wavelength emissions. This characteristic consistently permitted the detection of 10 nm, 50 nm, and 100 nm Ag NP particles internalized within the RAW cells by flow cytometry. A functional distinction between monocyte subsets within the RAW 264.7 cell line was noted as Ag NP are taken up by the F4/80+ subset of cells within the culture. Further, the internalization of Ag NP by the cells resulted in an increased cell surface expression of the Toll-like receptor (TLR) 3, but not TLR4.
Taken together, these results implicate the more mature macrophage in the ingestion of Ag NP; and an influence upon at least one of the Toll receptors present in macrophages following exposure to Ag NP. Further, our flow cytometric approach presents a potentially viable detection method for the identification of occult Ag NP material using an indicator cell line.
纳米粒子表现出独特的物理化学特性，为其应用提供了基础。由于其在细胞环境中存在的潜在和实际应用的多样性，需要彻底了解其后果。
本文通过流式细胞术研究了柠檬酸缓冲银（Ag）纳米粒子（NP）被 RAW264.7 鼠巨噬细胞系内化所引起的生物学效应。
用不同浓度的柠檬酸缓冲 Ag 纳米粒子培养细胞，并分析细胞体积、荧光发射和表面受体表达的变化。
在吞噬柠檬酸缓冲 Ag NP 后，RAW264.7 细胞的侧向散射（SSC）信号发生了明显变化，代表了 10nm、50nm 和 100nm 粒径的 NP。所有测试的柠檬酸化 Ag NP 内化的一个特征是检测到发射的红外和近红外波长发射。这一特征始终允许通过流式细胞术检测到内吞的 10nm、50nm 和 100nm Ag NP 颗粒。在 RAW264.7 细胞系中，单核细胞亚群之间存在功能上的区别，因为 Ag NP 被培养物中的 F4/80+细胞亚群摄取。此外，细胞内吞 Ag NP 导致细胞表面 Toll 样受体（TLR）3 的表达增加，但 TLR4 没有增加。
综上所述，这些结果表明，Ag NP 的摄取更依赖于成熟的巨噬细胞；并且在暴露于 Ag NP 后，巨噬细胞中至少有一种 Toll 受体受到影响。此外，我们的流式细胞术方法提出了一种潜在可行的检测方法，用于使用指示细胞系识别隐匿的 Ag NP 材料。
