Long-term evaluation of collagen and elastin following infrared (1100 to 1800 nm) irradiation.
BACKGROUND
Infrared irradiation stimulates collagen production, but histological differences in its long-term effects on type I versus type III collagen and elastin in human tissue are unclear.


OBJECTIVE
To investigate the effects of infrared irradiation.


METHODS
In vivo human tissues in sun-protected and sun-exposed areas were irradiated with infrared. Histological samples were analyzed, and visual changes were assessed up to 90 days post-treatment.


RESULTS
Infrared irradiation provided long-term increases in collagen and elastin levels on post-irradiation days 30, 60 and 90 compared to controls. Significant increases in type I collagen persisted until 30 and 60 days, and in sun-protected and exposed skin biopsies, respectively. Significant increases in type III collagen and elastin persisted until 90 days in both sun-protected and sun-exposed skin biopsies.


CONCLUSIONS
Infrared irradiation provides safe and effective long-term stimulation of collagen I and III and elastin, which is beneficial for improving skin laxity and wrinkles.
Tanaka
Yohei
Y
Department of Plastic and Reconstructive Surgery, Shinshu University School of Medicine, Matsumoto, Japan. yoheimd@yahoo.co.jp
Matsuo
Kiyoshi
K
Yuzuriha
Shunsuke
S
D000328:Adult; D024042:Collagen Type I / Q000378:metabolism / Q000528:radiation effects*; D024061:Collagen Type III / Q000378:metabolism / Q000528:radiation effects*; D004549:Elastin / Q000378:metabolism / Q000528:radiation effects*; D005260:Female; D006801:Humans; D007259:Infrared Rays; D008297:Male; D011829:Radiation Dosage; D012867:Skin / Q000378:metabolism / Q000528:radiation effects; D013997:Time Factors
D024042:Collagen Type I; D024061:Collagen Type III; D004549:Elastin