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035 a| (Sirsi) o794383442;

035 a| (OCoLC)794383442;

040 a| EREc| EREd| EREd| UtOrBLW;

049 a| EREE;

090 a| RA1270.N36;

100 1 a| Armstrong, Michael Christopher.?| UNAUTHORIZED;

245 10 a| Toxicity of metal oxide nanoparticles to Caenorhabditis elegans /c| by Michael Christopher Armstrong.;

260 a| [Greenville, N.C.] :b| East Carolina University,c| 2012.;

300 a| 89 pages :b| illustrations (color), digital, PDF file;

336 a| text2| rdacontent;

337 a| computer2| rdamedia;

338 a| online resource2| rdacarrier;

538 a| System requirements: Adobe Reader.;

538 a| Mode of access: World Wide Web.;

502 b| M.S.c| East Carolina Universityd| 2012.;

500 a| Presented to the faculty of the Department of Biology.;

500 a| Advisor: Xiaoping Pan.;

500 a| Title from PDF t.p. (viewed June 1, 2012).;

520 3 a| The increase in manufacturing and use of nanoparticles is expected to elevate levels of exposure to humans and other organisms. Presently, there is little understanding of the potential toxic effects of nanoparticle exposure. Nano-sized metal oxides, for example, may adversely affect biological systems due to their unique physiochemical properties. However, current findings are largely inconclusive and need further examination. The purpose of this study is to address the current knowledge gaps in metal oxide nanoparticle toxicity and to provide insight into the molecular mechanisms involved in exposure response. We evaluated the in vivo toxicity of CuO, ZnO, and TiO₂ nanoparticles to the soil nematode Caenorhabditis elegans (C. elegans). Metal oxide nanoparticle toxicity was assessed by using nematode mortality, fertility, and gene expression as endpoints. For toxicity assays, age-synchronized worms were exposed to nanoparticle treatments of various concentrations (range: 1-100 mg/L) and then evaluated for potential dose and/or time-dependent effects. The results of the lethality and fertility assays suggest that CuO and ZnO nanoparticles are more toxic than TiO₂ nanoparticles, causing increased nematode mortality as well as reduced offspring yields. Both CuO and ZnO nanoparticles were found to exhibit comparable toxicity to C. elegans within the tested dose range. In addition, ZnO nanoparticle-induced expression of select nematode genes was investigated using quantitative real-time PCR (qRT-PCR). Expression analysis revealed that gcs-1 was significantly up-regulated compared to the control after exposure to ZnO nanoparticles. As gcs-1 serves an important role in oxidative stress defense, functioning through the p38 mitogen-activated protein kinase (MAPK) pathway, these results might provide further insight into the molecular mechanisms involved in the response to metal oxide nanoparticle exposure.;

504 a| Includes bibliographical references.;

650 0 a| Nanoparticlesx| Toxicology.=| ^A210009;

650 0 a| Nanoparticlesx| Research.=| ^A210009;

650 0 a| Toxicity testingx| In vivo.=| ^A1113466;

650 0 a| Caenorhabditis elegans.=| ^A627930;

650 0 a| Copper oxidex| Toxicity testing.=| ^A1113089;

650 0 a| Zinc oxidex| Toxicity testing.=| ^A762265;

650 0 a| Titanium dioxidex| Toxicity testing.=| ^A275214;

653 a| Biology;

700 1 a| Pan, Xiaopingc| (Professor of biology),e| degree supervisor.=| ^A1443924;

710 2 a| East Carolina University.b| Department of Biology.=| ^A637467;

856 40 z| Access via ScholarShipu| http://hdl.handle.net/10342/3826;

949 o| jgml;

994 a| C0b| ERE;

596 a| 1 4;

998 a| 3063746;

999 a| CLICK ON WEB ADDRESSw| ASISc| 1i| 3063746-1001l| JNETm| JOYNERr| Ys| Yt| JNE3ETDu| 5/29/2012x| ETDz| JERESOURCE;

999 a| CLICK ON WEB ADDRESSw| ASISc| 1i| 3063746-2001l| HSLELECm| HSLr| Ys| Yt| HEETDu| 5/29/2012x| ETDz| HERESOURCE;

Toxicity of metal oxide nanoparticles to Caenorhabditis elegans / by Michael Christopher Armstrong.

Author/creator	Armstrong, Michael Christopher
Other author	Pan, Xiaoping (Professor of biology), degree supervisor.
Other author	East Carolina University. Department of Biology.
Format	Theses and dissertations
Publication Info	[Greenville, N.C.] : East Carolina University, 2012.
Description	89 pages : illustrations (color), digital, PDF file
Supplemental Content	Access via ScholarShip
Subjects	Nanoparticles--Toxicology. Nanoparticles--Research. Toxicity testing--In vivo. Caenorhabditis elegans. Copper oxide--Toxicity testing. Zinc oxide--Toxicity testing. Titanium dioxide--Toxicity testing.

Summary	The increase in manufacturing and use of nanoparticles is expected to elevate levels of exposure to humans and other organisms. Presently, there is little understanding of the potential toxic effects of nanoparticle exposure. Nano-sized metal oxides, for example, may adversely affect biological systems due to their unique physiochemical properties. However, current findings are largely inconclusive and need further examination. The purpose of this study is to address the current knowledge gaps in metal oxide nanoparticle toxicity and to provide insight into the molecular mechanisms involved in exposure response. We evaluated the in vivo toxicity of CuO, ZnO, and TiO₂ nanoparticles to the soil nematode Caenorhabditis elegans (C. elegans). Metal oxide nanoparticle toxicity was assessed by using nematode mortality, fertility, and gene expression as endpoints. For toxicity assays, age-synchronized worms were exposed to nanoparticle treatments of various concentrations (range: 1-100 mg/L) and then evaluated for potential dose and/or time-dependent effects. The results of the lethality and fertility assays suggest that CuO and ZnO nanoparticles are more toxic than TiO₂ nanoparticles, causing increased nematode mortality as well as reduced offspring yields. Both CuO and ZnO nanoparticles were found to exhibit comparable toxicity to C. elegans within the tested dose range. In addition, ZnO nanoparticle-induced expression of select nematode genes was investigated using quantitative real-time PCR (qRT-PCR). Expression analysis revealed that gcs-1 was significantly up-regulated compared to the control after exposure to ZnO nanoparticles. As gcs-1 serves an important role in oxidative stress defense, functioning through the p38 mitogen-activated protein kinase (MAPK) pathway, these results might provide further insight into the molecular mechanisms involved in the response to metal oxide nanoparticle exposure.
General note	Presented to the faculty of the Department of Biology.
General note	Advisor: Xiaoping Pan.
General note	Title from PDF t.p. (viewed June 1, 2012).
Dissertation note	M.S. East Carolina University 2012.
Bibliography note	Includes bibliographical references.
Technical details	System requirements: Adobe Reader.
Technical details	Mode of access: World Wide Web.

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Toxicity of metal oxide nanoparticles to Caenorhabditis elegans / by Michael Christopher Armstrong.

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