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Characterization, nanosafety, and cellular imaging of carbon nanotubes.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	Characterization, nanosafety, and cellular imaging of carbon nanotubes./
Author:	Braun, Elizabeth Irene.
Description:	1 online resource (160 pages)
Notes:	Source: Dissertation Abstracts International, Volume: 77-12(E), Section: B.
Subject:	Analytical chemistry. -
Online resource:	click for full text (PQDT)
ISBN:	9781369062106

Characterization, nanosafety, and cellular imaging of carbon nanotubes.
Braun, Elizabeth Irene.

Characterization, nanosafety, and cellular imaging of carbon nanotubes. - 1 online resource (160 pages)

Source: Dissertation Abstracts International, Volume: 77-12(E), Section: B.

Thesis (Ph.D.)--The University of Texas at Dallas, 2016.

Includes bibliographical references

This dissertation presents three important contributions to the field of carbon nanotube (CNT) environmental health and safety (EH&S). The first concerns aqueous CNT samples purified by centrifugation, the importance of thorough CNT sample characterizations, and improving the comparability of CNT toxicity assessments. Herein, using carboxylated multi-walled CNTs (cMWCNTs) suspended in water without a surfactant, a Boehm titrimetric method was developed and used to show for the first time that the surface acidity of oxidized carbon materials in aqueous cMWCNT suspensions was enriched by ~40% by a single low-speed centrifugation step. This significant difference in surface acidity between un-centrifuged and centrifuged cMWCNT suspensions has not been previously appreciated and is important because the degree of surface acidity is known to affect the interactions of cMWCNTs with biological systems. The second concerns the lack of CNT exposure data from laboratories where dry CNT powders are handled, the need to fully understand CNT release scenarios to make accurate EH&S risk assessments and to implement effective control measures, and the lack of chemical specificity with the current suite of instrumentation used to monitor the release of CNTs in workplaces. Herein, the first demonstration of Raman spectroscopy to unequivocally identify whether particulate matter collected from a multi-user analytical balance workstation comprised CNTs is presented. The approach revealed CNT contamination at this workstation, led to the identification of the exact CNT products, the users who handled these CNTs, and an improved protocol for safely weighing CNTs. The third concerns the need to more thoroughly understand how macrophage cells, the primary responders to foreign particles, process the CNTs that they accumulate. Herein, the distribution of poloxamer-coated, pristine and carboxylated MWCNTs within murine RAW 264.7 macrophage cells is assessed using Raman microscopy to image MWCNTs and immunofluorescence microscopy to image phagolysosomes. In both cases, MWCNTs were observed to co-localize in phagolysosomes, which supports the hypothesis that these cells can accumulate MWCNTs by phagocytosis. This evidence has implications with respect to the proper functioning of phagolysosomes in maintaining cellular health, as well as, being able to rationally design novel approaches to remediate potential chronic toxicity by accumulated MWCNTs.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2018

Mode of access: World Wide Web

ISBN: 9781369062106Subjects--Topical Terms:

1182118
Analytical chemistry.
Index Terms--Genre/Form:

554714
Electronic books.

Characterization, nanosafety, and cellular imaging of carbon nanotubes.
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100 1 $a Braun, Elizabeth Irene. $3 1189257
245 1 0 $a Characterization, nanosafety, and cellular imaging of carbon nanotubes.
264 0 $c 2016
300 $a 1 online resource (160 pages)
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500 $a Source: Dissertation Abstracts International, Volume: 77-12(E), Section: B.
500 $a Adviser: Paul Pantano.
502 $a Thesis (Ph.D.)--The University of Texas at Dallas, 2016.
504 $a Includes bibliographical references
520 $a This dissertation presents three important contributions to the field of carbon nanotube (CNT) environmental health and safety (EH&S). The first concerns aqueous CNT samples purified by centrifugation, the importance of thorough CNT sample characterizations, and improving the comparability of CNT toxicity assessments. Herein, using carboxylated multi-walled CNTs (cMWCNTs) suspended in water without a surfactant, a Boehm titrimetric method was developed and used to show for the first time that the surface acidity of oxidized carbon materials in aqueous cMWCNT suspensions was enriched by ~40% by a single low-speed centrifugation step. This significant difference in surface acidity between un-centrifuged and centrifuged cMWCNT suspensions has not been previously appreciated and is important because the degree of surface acidity is known to affect the interactions of cMWCNTs with biological systems. The second concerns the lack of CNT exposure data from laboratories where dry CNT powders are handled, the need to fully understand CNT release scenarios to make accurate EH&S risk assessments and to implement effective control measures, and the lack of chemical specificity with the current suite of instrumentation used to monitor the release of CNTs in workplaces. Herein, the first demonstration of Raman spectroscopy to unequivocally identify whether particulate matter collected from a multi-user analytical balance workstation comprised CNTs is presented. The approach revealed CNT contamination at this workstation, led to the identification of the exact CNT products, the users who handled these CNTs, and an improved protocol for safely weighing CNTs. The third concerns the need to more thoroughly understand how macrophage cells, the primary responders to foreign particles, process the CNTs that they accumulate. Herein, the distribution of poloxamer-coated, pristine and carboxylated MWCNTs within murine RAW 264.7 macrophage cells is assessed using Raman microscopy to image MWCNTs and immunofluorescence microscopy to image phagolysosomes. In both cases, MWCNTs were observed to co-localize in phagolysosomes, which supports the hypothesis that these cells can accumulate MWCNTs by phagocytosis. This evidence has implications with respect to the proper functioning of phagolysosomes in maintaining cellular health, as well as, being able to rationally design novel approaches to remediate potential chronic toxicity by accumulated MWCNTs.
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2018
538 $a Mode of access: World Wide Web
650 4 $a Analytical chemistry. $3 1182118
650 4 $a Chemistry. $3 593913
655 7 $a Electronic books. $2 local $3 554714
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690 $a 0485
710 2 $a ProQuest Information and Learning Co. $3 1178819
710 2 $a The University of Texas at Dallas. $b Chemistry. $3 1189258
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10151446 $z click for full text (PQDT)