title: Use of a rapid cytotoxicity screening approach to engineer a safer zinc oxide nanoparticle through iron doping.
abstract: The establishment of verifiably safe nanotechnology requires the development of assessment tools to identify hazardous nanomaterial properties that could be modified to improve nanomaterial safety. While there is a lot of debate of what constitutes appropriate safety screening methods, one approach is to use the assessment of cellular injury pathways to collect knowledge about hazardous material properties that could lead to harm to humans and the environment. We demonstrate the use of a multiparameter cytotoxicity assay that evaluates toxic oxidative stress to compare the effects of titanium dioxide (TiO(2)), cerium oxide (CeO(2)), and zinc oxide (ZnO) nanoparticles in bronchial epithelial and macrophage cell lines. The nanoparticles were chosen on the basis of their volume of production and likelihood of spread to the environment. Among the materials, dissolution of ZnO nanoparticles and Zn(2+) release were capable of ROS generation and activation of an integrated cytotoxic pathway that includes intracellular calcium flux, mitochondrial depolarization, and plasma membrane leakage. These responses were chosen on the basis of the compatibility of the fluorescent dyes that contemporaneously assess their response characteristics by a semiautomated epifluorescence procedure. Purposeful reduction of ZnO cytotoxicity was achieved by iron doping, which changed the material matrix to slow Zn(2+) release. In summary, we demonstrate the utility of a rapid throughput, integrated biological oxidative stress response pathway to perform hazard ranking of a small batch of metal oxide nanoparticles, in addition to showing how this assay can be used to improve nanosafety by decreasing ZnO dissolution through Fe doping.
authors.affiliation: Department of Medicine-Division of NanoMedicine, University of California, Los Angeles, California, USA.
authors.forename: Saji
authors.initials: S
authors.lastname: George
authors.forename: Suman
authors.initials: S
authors.lastname: Pokhrel
authors.forename: Tian
authors.initials: T
authors.lastname: Xia
authors.forename: Benjamin
authors.initials: B
authors.lastname: Gilbert
authors.forename: Zhaoxia
authors.initials: Z
authors.lastname: Ji
authors.forename: Marco
authors.initials: M
authors.lastname: Schowalter
authors.forename: Andreas
authors.initials: A
authors.lastname: Rosenauer
authors.forename: Robert
authors.initials: R
authors.lastname: Damoiseaux
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Bradley
authors.forename: Lutz
authors.initials: L
authors.lastname: Mädler
authors.forename: André E
authors.initials: AE
authors.lastname: Nel
mesh_terms: D000818:Animals; D002417:Cattle; D002460:Cell Line; D015195:Drug Design; D057166:High-Throughput Screening Assays; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D008856:Microscopy, Fluorescence; D053758:Nanoparticles / Q000737:chemistry*; D018384:Oxidative Stress / Q000187:drug effects; D015203:Reproducibility of Results; D012449:Safety; D013997:Time Factors; D015034:Zinc Oxide / Q000138:chemical synthesis / Q000737:chemistry* / Q000633:toxicity*
chemical_list: D007501:Iron; D015034:Zinc Oxide