title: Comparison of cellular toxicity caused by ambient ultrafine particles and engineered metal oxide nanoparticles.
abstract: OBJECTIVE
  The development of nanotechnology has spurred concerns about the health effects of exposure to nanoparticles (NPs) and ultrafine particles (UFPs). Toxicological data on NPs and UFPs may provide evidence to support the development of regulations to reduce the risk of particle exposure. We tried to provide fundamental data to determine differences in cytotoxicity induced by ambient UFPs and engineered metal oxide NPs (ZnO, NiO, and CeO2).
  
  
  METHODS
  UFPs were sampled by using of a nano micro-orifice uniform deposit impactor. Physicochemical characterization of the UFPs and nano metal oxide particles were studied by scanning electron microscopy and transmission electron microscopy. Cellular toxicity induced by the different particles was assessed by using of comprehensive approaches and compared after A549 cells were exposured to the particles.
  
  
  RESULTS
  All of the measured particles could damage A549 cells at concentrations ranging from 25 to 200 μg/mL. The lowest survival ratio and the highest lactate dehydrogenase level were caused by nano-ZnO particles, but the highest levels of intracellular reactive oxygen species (ROS) and percentages of apoptosis were observed in cells treated with the soluble fraction of ambient fine particles (PM1.8) at 200 μg/mL. Relatively high concentrations of anthropogenic metals, including Zn, Ni, Fe, and Cu, may be responsible for the higher toxicity of fine ambient particles compared with the ambient coarse particles and UFPs. The selected heavy metals (Zn, Ni, Fe, and Cu) were found to be located in the perinuclear and cytoplasmic areas of A549 cells. The distribution pattern of metals from ambient particles showed that distributions of the metals in A549 cells were not uniform and followed the pattern Cu>Zn>Fe>Ni, suggesting that Cu was absorbed by A549 cells more easily than the other metals.
  
  
  CONCLUSIONS
  Metal nanoparticles oxides and UFPs at low concentration could damage to cells, but the manufactured metal oxide nanoparticles are not highly toxic to lung cells compared to environmental particles. The local concentration effect of heavy metals in A549 cells, as well as the induction of oxidative stress by the particles, may be responsible for the damage observed to the cells.
authors.affiliation: School of environmental and chemical engineering, Shanghai University, No.333, Nanchen Rd, Shanghai, 200444, China. senlinlv@staff.shu.edu.cn.
authors.forename: Senlin
authors.initials: S
authors.lastname: Lu
authors.affiliation: School of environmental and chemical engineering, Shanghai University, No.333, Nanchen Rd, Shanghai, 200444, China. wenchzh@shu.edu.cn.
authors.forename: Wenchao
authors.initials: W
authors.lastname: Zhang
authors.affiliation: School of environmental and chemical engineering, Shanghai University, No.333, Nanchen Rd, Shanghai, 200444, China. ruizhang@shu.edu.cn.
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.affiliation: School of environmental and chemical engineering, Shanghai University, No.333, Nanchen Rd, Shanghai, 200444, China. pinwei@shu.edu.cn.
authors.forename: Pinwei
authors.initials: P
authors.lastname: Liu
authors.affiliation: School of environmental and chemical engineering, Shanghai University, No.333, Nanchen Rd, Shanghai, 200444, China. qxwang@shu.edu.cn.
authors.forename: Qiangxiang
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Institute for Environmental pollution and health, Shanghai University, Shanghai, 200444, China. yshang@shu.edu.cn.
authors.forename: Yu
authors.initials: Y
authors.lastname: Shang
authors.affiliation: School of environmental and chemical engineering, Shanghai University, No.333, Nanchen Rd, Shanghai, 200444, China. mhwu@staff.shu.edu.cn.
authors.forename: Minghong
authors.initials: M
authors.lastname: Wu
authors.affiliation: University of Edinburgh, Edinburgh, UK. ken.donaldson@edu.ac.uk.
authors.forename: Ken
authors.initials: K
authors.lastname: Donaldson
authors.affiliation: School of Science and Engineering, Saitama University, Saitama, 338-8570, Japan. seiyo@mail.saitama-u.ac.jp.
authors.forename: Qingyue
authors.initials: Q
authors.lastname: Wang
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002563:Cerium / Q000032:analysis / Q000737:chemistry / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D006801:Humans; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000032:analysis / Q000737:chemistry / Q000633:toxicity*; D009532:Nickel / Q000032:analysis / Q000737:chemistry / Q000633:toxicity*; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis / Q000737:chemistry / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013499:Surface Properties; D015034:Zinc Oxide / Q000032:analysis / Q000737:chemistry / Q000633:toxicity*
chemical_list: D052638:Particulate Matter; D017382:Reactive Oxygen Species; D002563:Cerium; C030583:ceric oxide; D009532:Nickel; C028007:nickel monoxide; D015034:Zinc Oxide