Background: Nonablative lasers are used for dermal collagen remodeling. Although clinical improvements have been reported using various laser devices, the mechanism of dermal collagen remodeling remains unknown.
Objective: To investigate the effects of energy fluences of the long-pulsed neodymium-doped yttrium aluminum garnet (Nd:YAG) nonablative laser on dermal collagen remodeling and evaluate the dermal collagen remodeling mechanism.
Materials and methods: Hairless mice were pretreated with ultraviolet B irradiation to produce photo-damage. The laser treatment used a long-pulse 1,064-nm Nd:YAG laser at energy fluences of 20, 40, and 60 J/cm(2) . The amount of dermal collagen and expressions of transforming growth factor beta (TGF-β), matrix metalloproteinase-1 (MMP-1), and tissue inhibitor of metalloproteinase-1 (TIMP-1) of laser treated skin were compared with those of nontreated control skin.
Results: The long-pulse Nd:YAG laser treatment increased dermal collagen and significantly increased TGF-β expression. The expression of MMP-1 decreased with low energy fluence. The expression of TIMP-1 was not significantly different.
Conclusion: Long-pulsed 1,064-nm Nd:YAG laser increases the dermal collagen in association with the increased expression of TGF-β.
© 2012 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.