FTIR Spectroscopy for Real-time Screening of Cell Response to Nanomaterial Exposure
PNNL uses Fourier transform infrared spectroscopy for real-time, live-cell, in situ screening of cellular responses to nano-particle exposure.
PNNL researchers have established a dedicated facility for live-cell FTIR spectroscopy for studying nanotoxicity and collected several spectra on different nano-systems. Research in this facility will help to discover biomarkers for a variety of biological responses to a variety of stresses, using infrared spectroscopy and microscopy.
Initial efforts demonstrated that attenuated total reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy has the sensitivity to monitor real-time changes in the response of macrophages to endotoxin, an important component of particulate matter. This was done by tracking the response of macrophages to lipopolysaccharide (LPS) in real-time.
Recent research:
- FTIR Spectra of RAW 264.7 Cells Treated with LPS: LPS induces an inflammatory response in macrophages, which in turn, is associated with protein carbonyl formation. We observe an increase in a peak at wave number 1652, corresponding to carbonyl bond (C=O), in LPS-treated macrophages, consistent with the inflammatory response.
- FTIR Observable Particokinetics: We have demonstrated that FTIR can observe and quantify the settling of 1 m silica particles with rates that tightly match predictions made using a physical particokinetic model.
- Advanced FTIR Data Analysis: We have completed an initial evaluation of FTIR spectra using advanced statistical methods, including principal component analysis (PCA). Our results indicate that the spectra associated with endotoxin- and 10 nm silica-treated cells can be clearly resolved using the PCA.
- Importance of Adsorbed Proteins in Guiding Nanomaterial Uptake and Toxicity: Studies with single-wall carbon nanotubes (SWCNTs) and silica nanoparticles indicate that proteins adsorbed to their surface significantly influence nanomaterial uptake and toxicity. These studies will ultimately be used to advance detailed interpretation of FTIR observable signatures associated with nanomaterial treated cells.
- Role of Albumin: Albumin was identified as the major fetal bovine or human serum/plasma protein adsorbed onto SWCNTs, while a distinct protein adsorption profile was observed when plasma from the Nagase analbuminemic rat was used. Damaged or structurally altered albumin is rapidly cleared from systemic circulation by scavenger receptors.
Publication:
Dutta D, SK Sundaram, BJ Riley, LS Fifield, JM Jacobs, GA Kaysen, BM Moudgil, and TJ Weber. 2007. "Adsorbed Proteins Influence the Biological Activity and Molecular Targeting of Nanomaterials," Toxicological Sciences, 10(1), 303-315.
Contact: SK Sundaram