Hamburg 2009 – scientific programme
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MO: Fachverband Molekülphysik
MO 2: Biomoleküle 1
MO 2.8: Talk
Monday, March 2, 2009, 15:45–16:00, VMP 6 HS-F
Quantitative detection of cholesterol in stratum corneum model systems by coherent anti-Stokes Raman scattering microspectroscopy — •Gregor Hehl1, Alexander Kovalev2, Patincharath Nandakumar3, and Andreas Volkmer1 — 13rd Insitute of Physics, University of Stuttgart, Stuttgart, Germany — 2MPI für Metallforschung, Stuttgart, Germany — 3Physics Department, Birla Institute of Technology and Science, Pilani-Goa, India
We report on the hyperspectral coherent anti-Stokes Raman scattering (CARS) imaging of lipids in stratum corneum, the top most barrier on the epidermis that prevents the penetration of external reagents through the skin. Investigations are carried out on mixtures consisting of ceramide, stearic acid and cholesterol, the three main lipid species of stratum corneum. Multiplex CARS microspectroscopy [1] is used for spatially and frequency resolved spectroscopic measurements with sub-micron and 5 cm-1 resolution, respectively. The reconstruction of linear Raman spectra from recorded multiplex CARS spectra is achieved by phase retrieval using the Maximum Entropy method [2]. Based on the characteristic Raman bands of cholesterol, ceramide and stearic acid in the C=C and C-H stretch region, we demonstrate the quantitative determination of the respective species concentrations, and the formation of cholesterol-rich domain structures in the electroporated stratum corneum model system.
[1] A. Volkmer, J. Phys. D: Appl. Phys. 38 (2005), R59-R81
[2] E. Vartiainen, K.-E. Peiponen, T. Asakura, Appl. Spectrosc. 50 (1996), 1283-1289