title: Effects of Nano-CeO₂ with Different Nanocrystal Morphologies on Cytotoxicity in HepG2 Cells.
abstract: Cerium oxide nanoparticles (nano-CeO₂) have been reported to cause damage and apoptosis in human primary hepatocytes. Here, we compared the toxicity of three types of nano-CeO₂ with different nanocrystal morphologies (cube-, octahedron-, and rod-like crystals) in human hepatocellular carcinoma cells (HepG2). The cells were treated with the nano-CeO₂ at various concentrations (6.25, 12.5, 25, 50, 100 μg/mL). The crystal structure, size and morphology of nano-CeO₂ were investigated by X-ray diffractometry and transmission electron microscopy. The specific surface area was detected using the Brunauer, Emmet and Teller method. The cellular morphological and internal structure were observed by microscopy; apoptotic alterations were measured using flow cytometry; nuclear DNA, mitochondrial membrane potential (MMP), reactive oxygen species (ROS) and glutathione (GSH) in HepG2 cells were measured using high content screening technology. The scavenging ability of hydroxyl free radicals and the redox properties of the nano-CeO₂ were measured by square-wave voltammetry and temperature-programmed-reduction methods. All three types of nano-CeO₂ entered the HepG2 cells, localized in the lysosome and cytoplasm, altered cellular shape, and caused cytotoxicity. The nano-CeO₂ with smaller specific surface areas induced more apoptosis, caused an increase in MMP, ROS and GSH, and lowered the cell's ability to scavenge hydroxyl free radicals and antioxidants. In this work, our data demonstrated that compared with cube-like and octahedron-like nano-CeO₂, the rod-like nano-CeO₂ has lowest toxicity to HepG2 cells owing to its larger specific surface areas.
authors.affiliation: Chinese Academy of Inspection and Quarantine, Beijing 100123, China. yyf2009319@foxmail.com.|Graduate University of Chinese Academy of Science, Beijing 100049, China. yyf2009319@foxmail.com.
authors.forename: Lili
authors.initials: L
authors.lastname: Wang
authors.affiliation: Chinese Academy of Inspection and Quarantine, Beijing 100123, China. aiwenchao126@163.com.
authors.forename: Wenchao
authors.initials: W
authors.lastname: Ai
authors.affiliation: Graduate University of Chinese Academy of Science, Beijing 100049, China. yyf2009319@foxmail.com.
authors.forename: Yanwu
authors.initials: Y
authors.lastname: Zhai
authors.affiliation: Chinese Academy of Inspection and Quarantine, Beijing 100123, China. lihs@aqsiqch.ac.cn.
authors.forename: Haishan
authors.initials: H
authors.lastname: Li
authors.affiliation: Graduate University of Chinese Academy of Science, Beijing 100049, China. kebinzh@163.com.
authors.forename: Kebin
authors.initials: K
authors.lastname: Zhou
authors.affiliation: Chinese Academy of Inspection and Quarantine, Beijing 100123, China. chenhm01@163.com.
authors.forename: Huiming
authors.initials: H
authors.lastname: Chen
mesh_terms: D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D002563:Cerium / Q000737:chemistry / Q000633:toxicity*; D004577:Electron Probe Microanalysis; D005978:Glutathione / Q000378:metabolism; D056945:Hep G2 Cells; D006801:Humans; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry / Q000633:toxicity; D010084:Oxidation-Reduction; D017382:Reactive Oxygen Species / Q000737:chemistry
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D002563:Cerium; C030583:ceric oxide; D005978:Glutathione
keywords: GSH; MMP; ROS; antioxidant; apoptosis; cytotoxicity; nano-CeO2