V. YASHUNSKY – 24 Mai

Over the past few years we study live cells using a unique infrared surface plasmon spectroscopy method. We measure infrared reflection spectrum in the vicinity of the critical angle using highrefractive index prism coated with semitransparent gold film.  This optical configuration, that also known as Kretschmann geometry, allows excitation of surface plasmon polaritons which traveling through the cells cultured on the gold film. By tracking the resonant wavelength and attenuation of the  surface  plasmon we characterize  the morphology  of cell  cultures  and  resolve  different phases in cell organization.
In addition to surface plasmon resonance in infrared range, we discovered a novel bio-optical phenomenon of waveguide modes propagating inside living cells. We found that such waveguide modes can be observed in intact epithelial cell monolayers and thus can provide complimentary information about cell connectivity and cell layer thickness.
Combined together surface plasmon and waveguide modes enable precise structural analysis of cell  populations  in  real-time  and  in  label-free  manner.  This  has  great  importance  for understanding the collective behavior of cells in the context of tissues and organs.

Reférences :
1.  Yashunsky, V. et al.  Real-Time Sensing of Enteropathogenic E. coli-Induced Effects on Epithelial Host Cell Height, Cell-Substrate Interactions, and Endocytic Processes by Infrared Surface Plasmon Spectroscopy . PloS ONE 8, e78431 (2013).
2.  Yashunsky, V. et al. Surface plasmon-based infrared spectroscopy for cell biosensing. Journal of Biomedical Optics 17, 081409-1-081409-8 (2012).
3.  Yashunsky, V. et al. Real-Time Sensing of Cell Morphology by Infrared Waveguide Spectroscopy. PloS ONE 7, e48454 (2012).
4.  Yashunsky, V., Lirtsman, V., Golosovsky, M., Davidov, D. & Aroeti, B. Real-time monitoring of epithelial cellcell  and  cell-substrate  interactions  by  infrared  surface  plasmon  spectroscopy.  Biophysical  Journal  99,  4028-4036 (2010).
5.  Yashunsky, V. et al. Real-time monitoring of transferrin-induced endocytic vesicle formation by mid-infrared surface plasmon resonance. Biophysical Journal 97, 1003-1012 (2009).