Stiffness of Human Hair Correlates with the Fractions of Cortical Cell Types

Ezawa, Yusuke and Nagase, Shinobu and Mamada, Akira and Inoue, Shigeto and Koike, Kenzo and Itou, Takashi (2019) Stiffness of Human Hair Correlates with the Fractions of Cortical Cell Types. Cosmetics, 6 (2). p. 24. ISSN 2079-9284

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Abstract

(1) Background: The objective of this work was to elucidate the hair microstructure which correlates with the stiffness of human hair fibers. (2) Methods: Bending moduli of hair fibers were evaluated for the hair samples from 156 Japanese female subjects. Hair transverse sections were dual-stained with fluorescent dyes which can stain para- and ortho-like cortical cells separately, and observed under a fluorescence light microscope. Atomic force microscopy nanoindentation measurements were performed to examine the modulus inside macrofibrils. (3) Results: The difference in bending moduli between the maximum and the minimum values was more than double. The hair of high bending modulus was rich in para-like cortical cells and the bending modulus significantly correlated with the fraction of para-like cortical cells to the whole cortex. On the other hand, the elastic moduli inside macrofibrils were almost same for the para- and ortho-like cortical cells. (4) Conclusions: Hair bending modulus depends on the fractions of the constitutional cortical cell types. The contribution of the intermacrofibrillar materials, which differed in their morphologies and amounts of para- and ortho-like cortical cells, is plausible as a cause of the difference in the modulus of the cortical cell types.

Item Type: Article
Subjects: Journal Eprints > Medical Science
Depositing User: Managing Editor
Date Deposited: 22 Mar 2023 05:46
Last Modified: 31 Jul 2024 12:23
URI: http://repository.journal4submission.com/id/eprint/906

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