Biomarker Discovery for Exposure of Macrophage Cells to Nanoparticles
S.K. Sundaram, T.J. Weber, R.S. Addleman, B.J. Riley and A.A. Schepmoes
Pacific Northwest National Laboratory, US
live lung cells, nanoparticles, toxicity, FTIR spectroscopy, flurescence microscopy
Harmful effects of particles to macrophage cells depend on their surface area and intrinsic toxicity of chemicals adsorbed on the surface. As particles become smaller, it is more likely they will harm the lung. For example, nanoparticles may gain access to sites, which larger particles cannot reach. Increasing commercialization and use of nanomaterials will result in increased exposure to nanoparticles through inhalation, ingestion, skin uptake, and injection of engineered nanomaterials. The complexity of issues relating nanoparticle composition, size, deposition in the lung, and cellular responses necessitates monitoring the health impacts and developing methods that can capture the multifaceted nature of this problem. We are developing capabilities to monitor health effects of nanoparticles in a variety of cell types using live cell infrared (IR) [e.g., attenuated total reflectance (ATR)] spectroscopy and fluorescence imaging techniques. In situ IR spectroscopy has desirable features since this technique does not require knowledge of the biological endpoint to monitor a priori and is not dependent on contrast agents for detection of the biological response. ATR measurements require the long term culture of cells on an IR-transparent substrate in a spatially restrictive manner. Specifically, ATR measurements capture information localized within about 1 m off the crystal surface. We have engineered an FT-IR system for live cell monitoring using ATR spectroscopy. We will present current progress on the development of surface functionalization chemistries to promote cell attachment and maintain cell viability within the spatial constraints necessary for ATR measurements. We examined dynamic changes in ATR spectra associated with treatment of RAW 264.7 macrophage-like cells with bacterial endotoxin (lipopolysaccharide, LPS) and carbon nanotubes. Specific chemical bond changes at a variety of wave numbers were observed and will be summarized. Based on our initial investigations, we are optimistic our combinatorial approach can contribute to our understanding of the health effects of nanoparticles.
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Nanotech 2006 Conference Program Abstract