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Proceedings Paper

A possible mechanism for visible-light-induced skin rejuvenation
Author(s): Leonardo Longo; Rachel Lubart; Harry Friedman; R. Lavie
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Paper Abstract

In recent years there has been intensive research in the field of non-ablative skin rejuvenation. This comes as a response to the desire for a simple method of treating rhytids caused by aging, UV exposure and acne scars. In numerous studies intense visible light pulsed systems (20-30J/cm2) are used. The mechanism of action was supposed to be a selective heat induced denaturalization of dermal collagen that leads to subsequent reactive synthesis. In this study we suggest a different mechanism for photorejuvenation based on light induced Reactive Oxygen Species (ROS) formation. We irradiated collagen in-vitro with a broad band of visible light, 400-800 nm, 12-22J/cm2, and used the spin trapping coupled with electron paramagnetic resonance (EPR) spectroscopy to detect ROS. In vivo, we used dose 30 J in average (35 for acnis scars, 25 for wrinkles and redness). Irradiated collagen results in hydroxyl and methyl radicals formation. We propose, as a new concept, that visible light at the intensity used for skin rejuvenation, 20-30J/cm2, produces high amounts of ROS which destroy old collagen fibers encouraging the formation of new ones. On the other hand at inner depths of the skin, where the light intensity is much weaker, low amounts of ROS are formed which are well known to stimulate fibroblast proliferation.

Paper Details

Date Published: 10 September 2004
PDF: 7 pages
Proc. SPIE 5610, Laser Florence 2003: A Window on the Laser Medicine World, (10 September 2004); doi: 10.1117/12.584393
Show Author Affiliations
Leonardo Longo, Univ. deglie Studi di Siena (Italy)
Rachel Lubart, Bar-Ilan Univ. (Israel)
Harry Friedman, Bar-Ilan Univ. (Israel)
R. Lavie, Bar-Ilan Univ. (Israel)


Published in SPIE Proceedings Vol. 5610:
Laser Florence 2003: A Window on the Laser Medicine World
Leonardo Longo; Alfons G. Hofstetter; Mihail-Lucian Pascu; Wilhelm R. A. Waidelich, Editor(s)

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