title: In vivo observation of age-related structural changes of dermal collagen in human facial skin using collagen-sensitive second harmonic generation microscope equipped with 1250-nm mode-locked Cr:Forsterite laser.
abstract: In vivo visualization of human skin aging is demonstrated using a Cr:Forsterite (Cr:F) laser-based, collagen-sensitive second harmonic generation (SHG) microscope. The deep penetration into human skin, as well as the specific sensitivity to collagen molecules, achieved by this microscope enables us to clearly visualize age-related structural changes of collagen fiber in the reticular dermis. Here we investigated intrinsic aging and/or photoaging in the male facial skin. Young subjects show dense distributions of thin collagen fibers, whereas elderly subjects show coarse distributions of thick collagen fibers. Furthermore, a comparison of SHG images between young and elderly subjects with and without a recent life history of excessive sun exposure show that a combination of photoaging with intrinsic aging significantly accelerates skin aging. We also perform image analysis based on two-dimensional Fourier transformation of the SHG images and extracted an aging parameter for human skin. The in vivo collagen-sensitive SHG microscope will be a powerful tool in fields such as cosmeceutical sciences and anti-aging dermatology.
authors.affiliation: Osaka University, Graduate School of Engineering Science, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan. yasui.takeshi@tokushima-u.ac.jp
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yasui
authors.forename: Makoto
authors.initials: M
authors.lastname: Yonetsu
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Tanaka
authors.forename: Yuji
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Shu-ichiro
authors.initials: S
authors.lastname: Fukushima
authors.forename: Toyonobu
authors.initials: T
authors.lastname: Yamashita
authors.forename: Yuki
authors.initials: Y
authors.lastname: Ogura
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Hirao
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Murota
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Araki
mesh_terms: D000328:Adult; D002610:Cheek; D024022:Fibrillar Collagens / Q000737:chemistry* / Q000648:ultrastructure*; D005583:Fourier Analysis; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007834:Lasers; D008297:Male; D008875:Middle Aged; D061848:Optical Imaging / Q000379:methods*; D012867:Skin / Q000737:chemistry*; D015595:Skin Aging / Q000502:physiology*; D013472:Sunlight; D014466:Ultraviolet Rays
chemical_list: D024022:Fibrillar Collagens