Exploring a biological tissue from atomic to macroscopic scale using synchrotron radiation: example of hair.

The study utilized synchrotron radiation-based diffraction and infrared microspectrometry to analyze hair structure and composition at various scales. It revealed that proteins and lipids, the main components of hair, are unevenly distributed and structurally distinct depending on their location within the hair fiber. The cuticle zone was found to be primarily composed of lipid granules, while the cortex and medulla zones consisted mainly of alpha-keratin. Infrared microspectroscopy showed differences in protein structure between the cuticle and cortex and a higher concentration of lipids in the medulla. The research demonstrated the complementary nature of these techniques and their potential applications in biological studies.