title: Examination of Single-Walled Carbon Nanotubes Uptake and Toxicity from Dietary Exposure: Tracking Movement and Impacts in the Gastrointestinal System.
abstract: Previous studies indicate that exposure of fish to pristine single-walled carbon nanotubes (SWCNTs) by oral gavage, causes no overt toxicity, and no appreciable absorption has been observed. However, in the environment, SWCNTs are likely to be present in dietary sources, which may result in differential impacts on uptake and biological effects. Additionally, the potential of these materials to sorb nutrients (proteins, carbohydrates, and lipids) while present in the gastrointestinal (GI) tract may lead to nutrient depletion conditions that impact processes such as growth and reproduction. To test this phenomenon, fathead minnows were fed a commercial diet either with or without SWCNTs for 96 h. Tracking and quantification of SWCNTs using near-infrared fluorescence (NIRF) imaging during feeding studies showed the presence of food does not facilitate transport of SWCNTs across the intestinal epithelia. Targeting genes shown to be responsive to nutrient depletion (peptide transporters, peptide hormones, and lipases) indicated thatpept2, a peptide transporter, andcck, a peptide hormone, showed differential mRNA expression by 96 h, a response that may be indicative of nutrient limitation. The results of the current study increase our understanding of the movement of SWCNTs through the GI tract, while the changes in nutrient processing genes highlight a novel mechanism of sublethal toxicity in aquatic organisms.
authors.affiliation: Department of Environmental and Global Health, Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611, USA. jbisesi@phhp.ufl.edu.
authors.forename: Joseph H
authors.initials: JH
authors.lastname: Bisesi
authors.affiliation: Department of Environmental and Global Health, Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611, USA. tweetiebird@ufl.edu.
authors.forename: Thuy
authors.initials: T
authors.lastname: Ngo
authors.affiliation: Department of Environmental and Global Health, Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611, USA. sponnavolu@ufl.edu.
authors.forename: Satvika
authors.initials: S
authors.lastname: Ponnavolu
authors.affiliation: Department of Civil and Environmental Engineering, Nicholas School of the Environment, Duke University, Durham, NC 27708, USA. keira.liu@duke.edu.
authors.forename: Keira
authors.initials: K
authors.lastname: Liu
authors.affiliation: Department of Environmental and Global Health, Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611, USA. ndenslow@ufl.edu.|Department of Physiological Sciences, Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611, USA. ndenslow@ufl.edu.
authors.forename: Candice M
authors.initials: CM
authors.lastname: Lavelle
authors.affiliation: Department of Civil, Architectural, and Environmental Engineering, The University of Texas Austin, Austin, TX 78712, USA. afrooz@utexas.edu.
authors.forename: A R M Nabiul
authors.initials: AR
authors.lastname: Afrooz
authors.affiliation: Department of Civil, Architectural, and Environmental Engineering, The University of Texas Austin, Austin, TX 78712, USA. navid.saleh@utexas.edu.
authors.forename: Navid B
authors.initials: NB
authors.lastname: Saleh
authors.affiliation: Department of Civil and Environmental Engineering, Nicholas School of the Environment, Duke University, Durham, NC 27708, USA. lee.ferguson@duke.edu.
authors.forename: P Lee
authors.initials: PL
authors.lastname: Ferguson
authors.affiliation: Department of Physiological Sciences, Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611, USA. ndenslow@ufl.edu.
authors.forename: Nancy D
authors.initials: ND
authors.lastname: Denslow
authors.affiliation: Department of Environmental and Global Health, Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611, USA. sabo@phhp.ufl.edu.
authors.forename: Tara
authors.initials: T
authors.lastname: Sabo-Attwood
keywords: fish; gastrointestinal system; gene expression; near-infrared fluorescence (NIRF); nutrient transporters; single-walled carbon nanotubes(SWCNTs); sorption