Molecular mechanisms underlying nanomaterial toxicity or biocompatibility
EMSL Project ID
47722
Abstract
Accumulating observations demonstrate the potential of engineered nanoparticles (NPs) to induce adverse effects in vivo and in vitro, but the properties that make a particle toxic or biocompatible are still unclear. Distinct physical and chemical properties of the NP engage and activate distinct proteins and cellular pathways that, in turn, govern the fate of the NP and its impact on the cell and ultimately on human health. The relationships between particle properties and these key cellular processes and response are far from being understood. This proposal covers research conducted under the NIEHS- and LDRD-funded projects, as well as the NSF-funded Center for Sustainable Nanotechnology, where we address the above questions. We will focus on NP types that have been widely used in industrial and commercial applications and therefore pose a potential for human exposure. These include cerium oxide and titanium dioxide NPs, as well as carbon nanotubes. In some of the studies, we will expose alveolar epithelial cells, grown at the air-liquid interface, to precise doses of mono-dispersed and well-defined aerosolized NPs. This approach will mimic the exposure conditions to inhaled NPs in vivo and gain new insights to airborne NP properties and cellular mechanisms governing their toxicity or biocompatibility. We will use time-lapse fluorescence imaging with single-molecule sensitivity, together with molecular biology techniques, to follow individual NPs or nano-scale aggregates in live cells and identify cellular interaction dynamics relevant to nanomaterial. We will also developed super resolution fluorescence microscopy techniques to determine the internalization pathways and intracellular fate of individual NPs with 10-20 nanometer resolution, and establish the use of helium ion microscopy to study individual NPs at the cell surface with sub-nanometer resolution. Our work will be guided by the working hypothesis that the exposure of alveolar cells to airborne NPs elicits cellular responses that inversely correlate with the ability of the particles to assimilate into the cellular environment. We will categorize the NPs as toxic, pro-inflammatory or biocompatible by quantifying pro-inflammatory gene and protein expression, oxidative stress response, membrane integrity and cell death. By correlating this information with the molecular processes inside the cell, it will be possible to identify NP properties that are toxic or biocompatible and understand the underlying mechanism.
Project Details
Start Date
2012-11-05
End Date
2013-11-17
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Eraso JM, LM Markillie, HD Mitchell, RC Taylor, G Orr, and W Margolin. 2014. "The highly conserved MraZ protein is a transcriptional regulator in Escherichia coli." Journal of Bacteriology 196(11):2053-2066. doi:10.1128/JB.01370-13
Gunsolus IL, D Hu, C Mihai, SE Lohse, CS Lee, M Torelli, RJ Hamers, C Murphy, G Orr, and CL Haynes. 2014. "Facile method to stain the bacterial cell surface for super-resolution fluorescence microscopy." Analyst 139(12):3174-3178. doi:10.1039/c4an00574k
Tilton SC, NJ Karin, A Tolic, Y Xie, X Lai, RF Hamilton, KM Waters, A Holian, Ph.D., FA Witzmann, and G Orr. 2014. "Three Human Cell Types Respond to Multi-walled Carbon Nanotubes and Titanium Dioxide Nanobelts with Cell-Specific Transcriptomic and Proteomic Expression patterns." Nanotoxicology 8(5):533-548. doi:10.3109/17435390.2013.803624