Effects of physicochemical properties of TiO2 nanomaterials for pulmonary inflammation, acute phase response and alveolar proteinosis in intratracheally exposed mice

Pernille Høgh Danielsen, Kristina Bram Knudsen, Janez Štrancar, Polona Umek, Tilen Koklič, Maja Garvas, Esa Vanhala, Sauli Savukoski, Yaobo Ding, Anne Mette Madsen, Nicklas Raun Jacobsen, Ingrid Konow Weydahl, Trine Berthing, Sarah Søs Poulsen, Otmar Schmid, Henrik Wolff, Ulla Birgitte Vogel*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Nanomaterial (NM) characteristics may affect the pulmonary toxicity and inflammatory response, including specific surface area, size, shape, crystal phase or other surface characteristics. Grouping of TiO2 in hazard assessment might be challenging because of variation in physicochemical properties. We exposed C57BL/6 J mice to a single dose of four anatase TiO2 NMs with various sizes and shapes by intratracheal instillation and assessed the pulmonary toxicity 1, 3, 28, 90 or 180 days post-exposure. The quartz DQ12 was included as benchmark particle. Pulmonary responses were evaluated by histopathology, electron microscopy, bronchoalveolar lavage (BAL) fluid cell composition and acute phase response. Genotoxicity was evaluated by DNA strand break levels in BAL cells, lung and liver in the comet assay. Multiple regression analyses were applied to identify specific TiO2 NMs properties important for the pulmonary inflammation and acute phase response. The TiO2 NMs induced similar inflammatory responses when surface area was used as dose metrics, although inflammatory and acute phase response was greatest and more persistent for the TiO2 tube. Similar histopathological changes were observed for the TiO2 tube and DQ12 including pulmonary alveolar proteinosis indicating profound effects related to the tube shape. Comparison with previously published data on rutile TiO2 NMs indicated that rutile TiO2 NMs were more inflammogenic in terms of neutrophil influx than anatase TiO2 NMs when normalized to total deposited surface area. Overall, the results suggest that specific surface area, crystal phase and shape of TiO2 NMs are important predictors for the observed pulmonary effects of TiO2 NMs.
Original languageEnglish
Article number114830
JournalTOXICOLOGY AND APPLIED PHARMACOLOGY
Volume386
Number of pages18
ISSN0041-008X
DOIs
Publication statusPublished - 2020

Keywords

  • Titanium dioxide
  • Nanoparticles
  • Crystal phase
  • Inflammation
  • Acute phase response
  • Pulmonary alveolar proteinosis

Cite this