Synthesis, characterization, and bioactivity of carboxylic acid-functionalized titanium dioxide nanobelts

Details

• Personal Author:
  Hamilton RF Jr. ; Holian A ; Li M ; Porter DW ; Wolfarth M ; Wu N ; Xiang C ; Yang F
• Description:
  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-a 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. [Description provided by NIOSH]
• Subjects:
  Acids Cells, Cultured Chelating Agents Environmental Monitoring Hazardous Substances Immune System Lung Occupational Health Respiratory System Safety
• Keywords:
  Alveolar-cells Bioactivation Carboxylic-acids Cell-cultures Chelating-agents Dioxides Exposure-assessment Immune-reaction In-vitro-study In-vivo-study Nanotechnology Toxic-effects

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• ISSN:
  1743-8977
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  Montana ; OSHA Region 3 ; OSHA Region 8 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  43
• Volume:
  11
• NIOSHTIC Number:
  nn:20045074
• Citation:
  Part Fibre Toxicol 2014 Sep; 11:43
• Contact Point Address:
  Andrij Holian, Center for Environmental Health Sciences, Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT 59812, USA
• Email:
  andrij.holian@umontana.edu
• CAS Registry Number:
  Humic acids (CAS RN 1415-93-6) ; Titania (CAS RN 13463-67-7)
• Federal Fiscal Year:
  2014
• NORA Priority Area:
  Manufacturing
• Peer Reviewed:
  True
• Source Full Name:
  Particle and Fibre Toxicology
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:f9bd5e4900eeb754abe3ac99d53af90e1eb78d0bbd70adde7093edaade47b56c374e43ef7e1d08aef8b94d68b306d16f6c48a8012d9c77abd9e1f8b371d4a022
• Download URL:
  https://stacks.cdc.gov/view/cdc/200606/cdc_200606_DS1.pdf
• File Type:
  [PDF - 1.85 MB ]