[16a-PA03-1~6] 3.3 Biomedical optics (formerly 3.4)

▲ [16a-PA03-5] Bio-Raman research on straight perm treatment of human grey hair

〇(M1)Jianhai He¹, Kazuyuki Suzuta², Len Ito², Mana Nemoto³, Shin-ichi Morita¹ (1.Graduate School of Science, Tohoku University, 2.Research & Development Department, Milbon, 3.Graduate School of Engineering, Tohoku University)

Keywords:Raman microscopy, human hair, protein secondary structure

In daily life, straight perm treatment is frequently used to change appearance of human hair, improving quality of life. The treatment is mainly by the chemical reactions (reduction and oxidization of S-S linkages) and the iron heating that accompanies sides effects to hair such as dryness, hair breakage, and loss of elasticity. We considered that research on the microscopic mechanism is effective to find a better condition for the straight perm, but the studies have been limitedly reported. Raman imaging is one of the powerful analytical techniques to characterize human hair at the molecular level. The purpose of this presentation is to investigate the microscopic mechanism of the straight perm treatment using Raman microscopy.
For spectral pretreatments, the baselines were corrected using polynomials; then the background (glue) was removed. After the perm treatment, the S-S signals became weaker. After the straight perm treatment, the signals became stronger especially for the center part in the image. The α-helix component corresponds to the ordered structure in the protein. It is interesting that, by the straight perm treatment, the protein in the cortex part became more ordered. The α-helix component in the amide I band may be used as a microscopic indicator to find a better condition for the straight perm treatment.