Differential long-term stimulation of type I versus type III collagen after infrared irradiation.
BACKGROUND
The dermis is composed primarily of type I (soft) and type III (rigid scar-like) collagen. Collagen degradation is considered the primary cause of skin aging. Studies have proved the efficacy of infrared irradiation on collagen stimulation but have not investigated the differential long-term effects of infrared irradiation on type I and type III collagen.


OBJECTIVE
To determine differential long-term stimulation of type I and type III collagen after infrared (1,100-1,800 nm) irradiation.


METHODS
In vivo rat tissue was irradiated using the infrared device. Histology samples were analyzed for type I and III collagen stimulation, visual changes from baseline, and treatment safety up to 90 days post-treatment.


RESULTS
Infrared irradiation provided long-term stimulation of type I collagen and temporary stimulation of type III collagen. Treatment also created long-term smoothing of the epidermis, with no observed complications.


CONCLUSIONS
Infrared irradiation provides safe, consistent, long-term stimulation of type I collagen but only short-term stimulation in the more rigid type III collagen. This is preferential for cosmetic patients looking for improvement in laxity and wrinkles while seeking smoother, more youthful skin.
Department of Plastic and Reconstructive Surgery, School of Medicine, Shinshu University, Matsumoto, Japan. info@clinicatanaka.jp
Yohei
Y
Tanaka
Kiyoshi
K
Matsuo
Shunsuke
S
Yuzuriha
Hiroshi
H
Shinohara
D000818:Animals; D024042:Collagen Type I / Q000096:biosynthesis*; D024061:Collagen Type III / Q000096:biosynthesis*; D007259:Infrared Rays; D008297:Male; D023421:Models, Animal; D051381:Rats; D017208:Rats, Wistar; D012867:Skin / Q000473:pathology / Q000528:radiation effects*
D024042:Collagen Type I; D024061:Collagen Type III