title: A Novel High-Throughput Approach to Measure Hydroxyl Radicals Induced by Airborne Particulate Matter.
abstract: Oxidative stress is one of the key mechanisms linking ambient particulate matter (PM) exposure with various adverse health effects. The oxidative potential of PM has been used to characterize the ability of PM induced oxidative stress. Hydroxyl radical (•OH) is the most destructive radical produced by PM. However, there is currently no high-throughput approach which can rapidly measure PM-induced •OH for a large number of samples with an automated system. This study evaluated four existing molecular probes (disodium terephthalate, 3'-p-(aminophenyl)fluorescein, coumarin-3-carboxylic acid, and sodium benzoate) for their applicability to measure •OH induced by PM in a high-throughput cell-free system using fluorescence techniques, based on both our experiments and on an assessment of the physicochemical properties of the probes reported in the literature. Disodium terephthalate (TPT) was the most applicable molecular probe to measure •OH induced by PM, due to its high solubility, high stability of the corresponding fluorescent product (i.e., 2-hydroxyterephthalic acid), high yield compared with the other molecular probes, and stable fluorescence intensity in a wide range of pH environments. TPT was applied in a high-throughput format to measure PM (NIST 1648a)-induced •OH, in phosphate buffered saline. The formed fluorescent product was measured at designated time points up to 2 h. The fluorescent product of TPT had a detection limit of 17.59 nM. The soluble fraction of PM contributed approximately 76.9% of the •OH induced by total PM, and the soluble metal ions of PM contributed 57.4% of the overall •OH formation. This study provides a promising cost-effective high-throughput method to measure •OH induced by PM on a routine basis.
authors.affiliation: Department of Environmental and Occupational Health, School of Public Health, Rutgers University, Piscataway, NJ 08854, USA. sonye@sph.rutgers.edu.
authors.forename: Yeongkwon
authors.initials: Y
authors.lastname: Son
authors.affiliation: Department of Pharmacology and Toxicology, Pharmacy College, Rutgers University, Piscataway, NJ 08854, USA. mishin@eohsi.rutgers.edu.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Mishin
authors.affiliation: Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, NJ 08854, USA. welshwj@rwjms.rutgers.edu.|Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA. welshwj@rwjms.rutgers.edu.
authors.forename: William
authors.initials: W
authors.lastname: Welsh
authors.affiliation: Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, NJ 08854, USA. shouen.lu@rutgers.edu.|Department of Biostatistics, School of Public Health, Rutgers University, Piscataway, NJ 08854, USA. shouen.lu@rutgers.edu.
authors.forename: Shou-En
authors.initials: SE
authors.lastname: Lu
authors.affiliation: Department of Environmental and Occupational Health, School of Public Health, Rutgers University, Piscataway, NJ 08854, USA. jlaskin@eohsi.rutgers.edu.|Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, NJ 08854, USA. jlaskin@eohsi.rutgers.edu.
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Laskin
authors.affiliation: Department of Environmental and Occupational Health, School of Public Health, Rutgers University, Piscataway, NJ 08854, USA. kipen@eohsi.rutgers.edu.|Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, NJ 08854, USA. kipen@eohsi.rutgers.edu.
authors.forename: Howard
authors.initials: H
authors.lastname: Kipen
authors.affiliation: Department of Environmental and Occupational Health, School of Public Health, Rutgers University, Piscataway, NJ 08854, USA. mengqi@sph.rutgers.edu.|Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, NJ 08854, USA. mengqi@sph.rutgers.edu.
authors.forename: Qingyu
authors.initials: Q
authors.lastname: Meng
mesh_terms: D000814:Aniline Compounds; D003374:Coumarins; D005452:Fluoresceins; D005456:Fluorescent Dyes; D017665:Hydroxyl Radical / Q000032:analysis*; D008670:Metals; D015336:Molecular Probe Techniques; D015335:Molecular Probes; D052638:Particulate Matter / Q000737:chemistry*; D010795:Phthalic Acids / Q000032:analysis; D020160:Sodium Benzoate
chemical_list: D000814:Aniline Compounds; D003374:Coumarins; D005452:Fluoresceins; D005456:Fluorescent Dyes; D008670:Metals; D015335:Molecular Probes; D052638:Particulate Matter; D010795:Phthalic Acids; C508569:aminophenyl fluorescein; D017665:Hydroxyl Radical; C406866:2-hydroxyterephthalic acid; C011363:terephthalic acid; D020160:Sodium Benzoate; C104227:coumarin-3-carboxylic acid
keywords: air pollution; exposure assessment; high throughput analysis; hydroxyl radical; molecular probe; oxidative potential; oxidative stress; particulate matter