1 / 18

Department of Dermatology and Allergy Charité - Universitätsmedizin Berlin

Department of Dermatology and Allergy Charité - Universitätsmedizin Berlin. Overview of noninvasive methods for determination of carotenoid concentrations in mammalian skin. M.E. Darvin , J. Lademann Charité-Universitätsmedizin Berlin, Center of Experimental and Applied Cutaneous

amir-bryan
Télécharger la présentation

Department of Dermatology and Allergy Charité - Universitätsmedizin Berlin

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Department of Dermatology and Allergy Charité - Universitätsmedizin Berlin Overview of noninvasive methods for determination of carotenoid concentrations in mammalian skin M.E. Darvin, J. Lademann Charité-Universitätsmedizin Berlin, Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, Venerology and Allergology, Berlin, Germany

  2. Carotenoidsareknowntobe powerful antioxidantsactingeffectivelyagainstreactiveoxygenspecies. The abilityofcarotenoidstoquenchoxygenradicals (includingsingletoxygen) isrelatedtotheconjugatedcarbon double-bond system, andmaximumprotectionisprovidedbythosehavingnineormore double bonds. Most prominent carotenoidsbeingaccumulated in human skinare beta-carotene (9 double bonds) andlycopene (11 double bonds) andtheirisomers.

  3. High-performance liquid chromatography (HPLC) is a widely used „gold standard“ method for determination of carotenoids. This method is highly invasive, time-consuming and expansive. Moreover, the oxidation of carotenoids during the sample preparation cannot be excluded. For analyzing the kinetics of carotenoids in the skin noninvasive methods are irreplaceable and should be performed.

  4. Carotenoids cannot be detected in the skin using fluorescence analyses because their fluorescence efficiency is very low (10-4-10-5). Optical methods for noninvasive determination of carotenoids in mammalian skin: 1. resonance Raman spectroscopy 2. Raman microscopy 3. reflection spectroscopy 4. skin color measurements

  5. Resonance Raman spectroscopy 1 – Ar+ laser; 2 – lens system; 3 – filter (488nm/514.5nm); 4, 9 – optical fiber; 5 – excitation channel; 6 – optical imaging system; 7 – skin; 8 – receiving channel; 10 – spectrometer; 11 – CCD; 2 – computer; 13 – photo detector Darvin et al. J. Biomed. Opt. 18(6), 061230, 2013

  6. Fiber optic-based resonance Raman spectroscopy for endoscopic measurement of carotenoid oxidative breakdown in living tissue Excitation wavelength 488 nm Brandon et al. Cancer Prev. Res. 3(4): 529-538, 2010

  7. Resonance Raman spectroscopy Advantages: - measurement quickness - high sensitivity - selectivity between beta-carotene and lycopene - increasing the measurement accuracy using photobleaching effect - measurement stability - transportability Limitations: - influence of other carotenoids - reabsorption of Raman signal at 527.2 nm by lycopene Darvin et al. J. Biomed. Opt. 18(6), 061230, 2013

  8. Raman microscopy 1 – laser (NIR or VIS); 2 – short-pass filter; 3 – objective; 4 – mirrors; 5 – skin; 6 – laser rejection filter; 7 – lens; 8 – optical fiber; 9 – spectrometer; 10 – CCD; 11 – computer Darvin et al. J. Biomed. Opt. 18(6), 061230, 2013

  9. Raman microscopy Advantages: - measurementof axial distributionofcarotenoids in theskin Limitations: - lowandverylowcarotenoidconcentrationsare not detectableunder non-resonant excitation - bulkysize - high price Darvin et al. J. Biomed. Opt. 18(6), 061230, 2013

  10. Reflectancespectroscopy 1 – LED (440 - 490 nm); 2 – skin; 3 – focusing system; 4 – replicated holographic grating spectrometer; 5 – Bluetooth Darvin et al. J. Biophotonics 5(7): 550-558, 2012

  11. „Scanner“ in use

  12. Reflectancespectroscopy Advantages: - lowprice - measurementstability - compactsize(easy totransport) - independencefromelectricmains Limitations: - lowcarotenoidconcentrationsare not detectable - couldbeappliedonly on thenaland plantar skinareaswheretheepidermisisthickenoughandinfluence of melaninandbloodchromophoresislesspronounced Darvin et al. J. Biophotonics 5(7): 550-558, 2012 Darvin et al. J. Biomed. Opt. 18(6), 061230, 2013

  13. Skin colormeasurements b*-valuecharacterizingyellowness oftheskinservesas a measuring parameterfor epidermal carotenoids Bersha. Master Thesis, University of Eastern Finland, 21 June 2010

  14. b*-value was foundtocorrelate withconcentrationofcarotenoids in human epidermis Alaluf et al. Journal of Nutrition 132(3), 399-403, 2002

  15. Skin colormeasurements Advantages: - lowprice - compactsize(easy totransport) - independencefromelectricmains Limitations: - lowcarotenoidconcentrationsare not detectable - couldbeappliedonly on thenaland plantar skinareaswheretheepidermisisthickenoughandinfluenceofmelaninandbloodchromophoresislesspronounced - measurementstabilityis not high enough Darvin et al. J. Biomed. Opt. 18(6), 061230, 2013

  16. Conclusions Comparison of optical methods for measurement of carotenoids in human skin

  17. Thank you for your attention

More Related