Graduate School of Biomedical Engineering, The University of New South Wales, Sydney NSW 2052, Australia.
Biomaterials. 2012 Nov;33(31):7915-24. doi: 10.1016/j.biomaterials.2012.07.024. Epub 2012 Jul 28.
Cerium oxide nanoparticles (nanoceria) are promising materials for intracellular oxygen free radical scavenging providing a potential therapy for reactive oxygen species (ROS)-mediated inflammatory processes. In this study rhombohedral-shaped nanoceria were synthesized by flame spray pyrolysis with tuneable particle diameters between 3 and 94 nm by changing the liquid precursor flow rate. Monocytes and macrophages are major players in inflammatory processes as their production of ROS species has important downstream effects on cell signalling. Therefore, this study examined the ability of the nanoceria to be internalised by the human monocytic cell line, U937, and scavenge intracellular ROS. U937 cells activated in the presence of phorbol 12-myristate 13-acetate (PMA) were found to be more responsive to the nanoceria than U937 cells, which may not be surprising given the role of monocyte/macrophages in phagocytosing foreign material. The smaller particles were found to contain more crystal lattice defects with which to scavenge ROS, however a greater proportion of both the U937 and activated U937 cell populations responded to the larger particles. Hence all nanoceria particle sizes examined in this study were equally effective in scavenging intracellular ROS.
氧化铈纳米颗粒（纳米氧化铈）是一种有前途的用于清除细胞内氧自由基的材料，为活性氧物质（ROS）介导的炎症过程提供了一种潜在的治疗方法。在这项研究中，通过火焰喷雾热解法合成了菱面体形状的纳米氧化铈，通过改变液体前体的流速可以调节粒径在 3 到 94nm 之间。单核细胞和巨噬细胞是炎症过程中的主要参与者，因为它们产生的 ROS 物质对细胞信号转导有重要的下游影响。因此，本研究研究了纳米氧化铈被人单核细胞系 U937 内化并清除细胞内 ROS 的能力。与 U937 细胞相比，在佛波醇 12-肉豆蔻酸 13-乙酸酯（PMA）存在下激活的 U937 细胞对纳米氧化铈的反应更敏感，考虑到单核细胞/巨噬细胞在吞噬外来物质中的作用，这可能并不奇怪。较小的颗粒被发现含有更多的晶格缺陷，以清除 ROS，然而，更大比例的 U937 和激活的 U937 细胞群体对较大的颗粒有反应。因此，本研究中检查的所有纳米氧化铈颗粒尺寸在清除细胞内 ROS 方面同样有效。
