title: Cellular uptake and reactive oxygen species modulation of cerium oxide nanoparticles in human monocyte cell line U937.
abstract: 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.
authors: Graduate School of Biomedical Engineering, The University of New South Wales, Sydney NSW 2052, Australia. m.lord@unsw.edu.au
authors: Megan S
authors: MS
authors: Lord
authors: MoonSun
authors: M
authors: Jung
authors: Wey Yang
authors: WY
authors: Teoh
authors: Cindy
authors: C
authors: Gunawan
authors: James A
authors: JA
authors: Vassie
authors: Rose
authors: R
authors: Amal
authors: John M
authors: JM
authors: Whitelock
mesh_terms: D002470:Cell Survival; D002563:Cerium / Q000737:chemistry*; D004705:Endocytosis; D005434:Flow Cytometry; D005453:Fluorescence; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D009000:Monocytes / Q000166:cytology* / Q000378:metabolism*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013059:Spectrum Analysis, Raman; D013696:Temperature; D020298:U937 Cells
chemical_list: D017382:Reactive Oxygen Species; D002563:Cerium; C030583:ceric oxide