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Proceedings Paper

Cutaneous porphyrins exhibit anti-stokes fluorescence that is detectable in sebum (Conference Presentation)
Author(s): Giselle Tian; Haishan Zeng; Jianhua Zhao; Zhenguo Wu; Mohammed Al Jasser; Harvey Lui; David I. Mclean

Paper Abstract

Porphyrins produced by Propionibacterium acnes represent the principal fluorophore associated with acne, and appear as orange-red luminescence under the Wood’s lamp. Assessment of acne based on Wood’s lamp (UV) or visible light illumination is limited by photon penetration depth and has limited sensitivity for earlier stage lesions. Inducing fluorescence with near infrared (NIR) excitation may provide an alternative way to assess porphyrin-related skin disorders. We discovered that under 785 nm CW laser excitation PpIX powder exhibits fluorescence emission in the shorter wavelength range of 600-715 nm with an intensity that is linearly dependent on the excitation power. We attribute this shorter wavelength emission to anti-Stokes fluorescence. Similar anti-Stokes fluorescence was also detected focally in all skin-derived samples containing porphyrins. Regular (Stokes) fluorescence was present under UV and visible light excitation on ex vivo nasal skin and sebum from uninflamed acne, but not on nose surface smears or sebum from inflamed acne. Co-registered CW laser-excited anti-Stokes fluorescence and fs laser-excited multi-photon fluorescence images of PpIX powder showed similar features. In the skin samples because of the anti-Stokes effect, the NIR-induced fluorescence was presumably specific for porphyrins since there appeared to be no anti-Stokes emission signals from other typical skin fluorophores such as lipids, keratins and collagen. Anti-Stokes fluorescence under NIR CW excitation is more sensitive and specific for porphyrin detection than UV- or visible light-excited regular fluorescence and fs laser-excited multi-photon fluorescence. This approach also has higher image contrast compared to NIR fs laser-based multi-photon fluorescence imaging. The anti-Stokes fluorescence of porphyrins within sebum could potentially be applied to detecting and targeting acne lesions for treatment via fluorescence image guidance.

Paper Details

Date Published: 27 April 2016
PDF: 1 pages
Proc. SPIE 9689, Photonic Therapeutics and Diagnostics XII, 968910 (27 April 2016); doi: 10.1117/12.2217210
Show Author Affiliations
Giselle Tian, The BC Cancer Agency Research Ctr. (Canada)
Haishan Zeng, The BC Cancer Agency Research Ctr. (Canada)
Jianhua Zhao, The BC Cancer Agency Research Ctr. (Canada)
Zhenguo Wu, The BC Cancer Agency Research Ctr. (Canada)
Mohammed Al Jasser, Photomedicine Institute (Canada)
The Univ. of British Columbia (Canada)
Harvey Lui, Photomedicine Institute, The Univ. of British Columbia (Canada)
David I. Mclean, Photomedicine Institute (Canada)
The Univ. of British Columbia (Canada)

Published in SPIE Proceedings Vol. 9689:
Photonic Therapeutics and Diagnostics XII
Hyun Wook Kang; Guillermo J. Tearney M.D.; Melissa C. Skala; Bernard Choi; Andreas Mandelis; Brian J. F. Wong M.D.; Justus F. Ilgner M.D.; Nikiforos Kollias; Paul J. Campagnola; Kenton W. Gregory M.D.; Laura Marcu; Haishan Zeng, Editor(s)

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