A highly resistant structure between the cuticle and the cortex of human hair III: Characterzation of the structure CARB

Abstract

Objective It was previously reported that a highly resistant structure, which functions as a barrier against the penetration of dyes, is present at the interface between the cuticle and the cortex of human hair. That structure was named CARB, cuticle anchored resistant base. The goal of this study was to clarify the formation and composition of the structure CARB. Methods Cuticular substructures were observed from the keratinized area of each hair to its root end. The positions where the CARB structure appeared were isolated, and the barrier ability before and after that structure was evaluated. The distributions of glycolipid and cystine were measured using a nano‐IR and a transmission electron microscope (TEM). Results Cuticular substructures were fully constructed several mm from the hair bulb of the hairs observed. The results show that keratinization at the distal side of the cuticle cell precedes that of the proximal side, and CARB is fully constructed last among the substructures. Glycolipid was preferentially distributed at CARB in the keratinized area. The cystine content of CARB is lower than that of the A‐layer; however, it is slightly higher than that of the exocuticle and the inner layer. Conclusion These results demonstrate that CARB is produced in the final stage of keratinization of the cuticle layers. The rich contents of glycolipid and cystine might contribute to its resistant property.

Recent Progress in Hair Science and Trichology

“…Each sheet is approximately 0.5 µm thick and roughly 100 µm× 50 µm in size with rounded corners, resulting in an overall cuticle thickness up to 5 µm (shown in Fig. 2 (a) ) 17,19,20,22,23) . The longitudinal direction that the overlapping sheets are tilted at is approximately 3-5° to the hair s growth axis.…”

“…Recently, Takahashi has proposed a new structure named CARB (cuticle anchored resistant base) , which is located at the interface between the cuticle and cortex and is just one outer layer from the cuticle-cortex CMC 22,23) . According to Takahashi, the penetration barrier at the interface between the cuticle and cortex is not the CMC, but the CARB.…”

“…In the first section of this review, the latest reports regarding the structure and mechanical properties of hair are summarized. The structure of hair has been investigated mainly by using small angle X-ray scattering (SAXS) 16−18) , atomic force microscopy (AFM) 17, 19−21) , transmission electron microscopy (TEM) 17,22,23) , Fourier transform infrared spectroscopy (FT-IR) 24−29) , and Raman spectroscopy 30−34) . In addition to these techniques, atomic force microscopy integrated with infrared spectroscopy (AFM-IR) 35,36) , focused ion beam scanning electron microscopy (FIB-SEM) 37) , and scanning transmission electron microscopy (STEM) 37) have been recently applied in hair research.…”

Rice Derivatives in Hair Protecting

“…Microscopy and image analyses are used to study the structure of the hair, the penetration of materials, and the presence of substances deposited on the hair and to evaluate its damage [6]. Various studies have been performed by fluorescence microscopy (conventional and confocal) [6,8], by scanning electron microscopy (SEM) [7,9,10], by transmission electron microscopy (TEM) [7,11,12], and by atomic force microscopy (AFM) [13,14].…”

“…Pavani et al [15] applied fluorescence spectroscopy for the assessment of hair photo-induced damage. Fourier transform infrared spectroscopy can be applied for the detection of molecules that bind to the hair, for the study of structural and morphological variations of the hair due to bleaching and/or coloring and for the study of the state of hydration induced by the application of a conditioning product [11,16].…”