Document Type
Article
Publication Date
2014
College/Unit
Statler College of Engineering and Mining Resources
Department/Program/Center
Mechanical and Aerospace Engineering
Abstract
Background
Surface modification strategies to reduce engineered nanomaterial (ENM) bioactivity have been used successfully in carbon nanotubes. This study examined the toxicity and inflammatory potential for two surface modifications (humic acid and carboxylation) on titanium nanobelts (TNB).
Methods
The in vitro exposure models include C57BL/6 alveolar macrophages (AM) and transformed human THP-1 cells exposed to TNB for 24 hrs in culture. Cell death and NLRP3 inflammasome activation (IL-1β release) were monitored. Short term (4 and 24 hr) in vivo studies in C57BL/6, BALB/c and IL-1R null mice evaluated inflammation and cytokine release, and cytokine release from ex vivo cultured AM.
Results
Both in vitro cell models suggest that the humic acid modification does not significantly affect TNB bioactivity, while carboxylation reduced both toxicity and NLRP3 inflammasome activation. In addition, short term in vivo exposures in both C57BL/6 and IL-1R null mouse strains demonstrated decreased markers of inflammation, supporting the in vitro finding that carboxylation is effective in reducing bioactivity. TNB instillations in IL-1R null mice demonstrated the critical role of IL-1β in initiation of TNB-induced lung inflammation. Neutrophils were completely absent in the lungs of IL-1R null mice instilled with TNB for 24 hrs. However, the cytokine content of the IL-1R null mice lung lavage samples indicated that other inflammatory agents, IL-6 and TNF-α were constitutively elevated indicating a potential compensatory inflammatory mechanism in the absence of IL-1 receptors.
Conclusions
Taken together, the data suggests that carboxylation, but not humic acid modification of TNB reduces, but does not totally eliminate bioactivity of TNB, which is consistent with previous studies of other long aspect ratio nanomaterials such as carbon nanotubes.
Digital Commons Citation
Hamilton, Raymond F.; Wu, Nianqiang; Xiang, Chengcheng; Li, Ming; Yang, Feng; Wolfarth, Michael; Porter, dale W.; and Holian, Andrij, "Synthesis, characterization, and bioactivity of carboxylic acid-functionalized titanium dioxide nanobelts" (2014). Faculty & Staff Scholarship. 2475.
https://researchrepository.wvu.edu/faculty_publications/2475
Source Citation
Hamilton, R.F., Wu, N., Xiang, C. et al. Synthesis, characterization, and bioactivity of carboxylic acid-functionalized titanium dioxide nanobelts. Part Fibre Toxicol 11, 43 (2014). https://doi.org/10.1186/s12989-014-0043-7
Comments
© 2014 Hamilton et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.