Thumbnail Image
Publication

An investigation into the mechanism of toxicity of zinc oxide nanoparticles.

Sharma, Vyom
Publication Date
2012-04-19
End of Embargo
Supervisor
Anderson, Diana
Dhawan, A.
Keywords
Zinc oxide, Nanoparticles, Toxicity, Exposure, Human health, Cellular interactions, Human epidermal keratinocytes, Human epidermal cells, Human liver cells, Environmental health and safety, Mouse model
Rights
Creative Commons License
The University of Bradford theses are licenced under a Creative Commons Licence.
Peer-Reviewed
Open Access status
Accepted for publication
Institution
University of Bradford
Department
School of Life Sciences
Awarded
2011
Embargo end date
Collections
Theses
Show all metadata
Files
Thumbnail Image
Vyom PhD thesis-final submission.pdf
Adobe PDF, 10.47 MB
Additional title
Abstract
The wide scale use of ZnO nanoparticles (NPs) in the world consumer market has resulted in likelihood of exposure to human beings. The present study was aimed to assess the in vitro and in vivo interactions of ZnO NPs in the mammalian system and to elucidate the possible mechanism of their toxicity. Our in vitro results using human epidermal cells (A431), primary human epidermal keratinocytes and human liver cells (HepG2) demonstrated that cells exposed to ZnO NPs exhibit a decrease in cell viability which was independent of NP dissolution. ZnO NPs also induced oxidative DNA damage as evidenced by an increase in the Fpg sensitive sites. The reactive oxygen species triggered a decrease in mitochondrial membrane potential and an increase in the ratio of Bax/Bcl2 leading to apoptosis through the intrinsic pathway. In addition, ZnO NPs induced phosphorylation of JNK, P38 and P53ser15. The results from our in vivo studies using a mouse model showed that ZnO NPs induce lipid peroxidation, oxidative DNA damage and apoptosis in liver which further confirmed our in vitro findings. The data from the present study provide valuable insights into the cellular interactions of ZnO NPs and the underlying molecular mechanism of their toxicity. The results also stress the need for a comprehensive environmental health and safety assessment of engineered nanomaterials to ensure safer nanotechnology based products.
URI
http://hdl.handle.net/10454/5421
Version
Citation
Link to publisher’s version
Link to published version
Link to Version of Record
Type
Thesis
Qualification name
PhD
Notes