title: Investigation of dyeing behavior of oxidative dye in fine structures of the human hair cuticle by nanoscale secondary ion mass spectrometry.
abstract: OBJECTIVE
  In oxidative coloring, the hair cuticle layers are not only the penetration pathway for active ingredients but also one of the most important dyeing regions. The dyeing mechanism of oxidative dyes in fine structures of the cuticle remains unclear. To investigate the dyeing behavior of oxidative dyes in fine structures of the cuticle, hair cross-sections were analyzed by nanoscale secondary ion mass spectrometry (NanoSIMS).
  
  
  METHODS
  The preparation method of hair cross-section for NanoSIMS measurement was improved. Improved hair cross-sections were analyzed using NanoSIMS.
  
  
  RESULTS
  The cuticle layer thickness of the hair cross-section could be widened. It was confirmed that (12) C(-) ions were more strongly detected from endocuticle than from other fine structures of cuticle. The NanoSIMS (12) C(-) image and hue saturation intensity (HSI) D(-) /(1) H(-) ratio image of the hair, dyed with deuterium-labeled oxidative dye, indicated that the endocuticle had a higher D(-) /(1) H(-) ratio than the other fine structures of the cuticle. It was substantiated that more colored chromophores were fixated in the endocuticle than in other fine structures of the cuticle.
  
  
  CONCLUSIONS
  The dyeing behavior of oxidative dyes in fine structures of hair cuticle was substantiated by NanoSIMS analysis using the improved hair cross-section preparation method.
authors.affiliation: General Research & Development Institute, Hoyu Co., Ltd., Nagakute, Aichi, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kojima
authors.affiliation: General Research & Development Institute, Hoyu Co., Ltd., Nagakute, Aichi, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Yamada
authors.affiliation: General Research & Development Institute, Hoyu Co., Ltd., Nagakute, Aichi, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Saito
authors.affiliation: General Research & Development Institute, Hoyu Co., Ltd., Nagakute, Aichi, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Nawa
authors.affiliation: General Research & Development Institute, Hoyu Co., Ltd., Nagakute, Aichi, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Isobe
authors.affiliation: General Research & Development Institute, Hoyu Co., Ltd., Nagakute, Aichi, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan.
authors.forename: D
authors.initials: D
authors.lastname: Aoki
authors.affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Matsushita
authors.affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Fukushima
mesh_terms: D065966:Absorption, Physicochemical; D006197:Hair / Q000737:chemistry* / Q000648:ultrastructure*; D006202:Hair Dyes / Q000737:chemistry*; D006801:Humans; D007564:Japan; D036103:Nanotechnology / Q000379:methods; D016877:Oxidants / Q000737:chemistry*; D010655:Phenylenediamines / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D014018:Tissue Distribution
chemical_list: D006202:Hair Dyes; D016877:Oxidants; D010655:Phenylenediamines
keywords: NanoSIMS; cuticle; dyeing behavior; human hair; oxidative dye