Making Visible the Lipids in Human Hair Using ASE-SEM

The lipids in the cell membrane complex (CMC) of human hair play a role in permeation and diffusion of chemicals in hair, in cell cohesion, and in the mechanical strength of hair. Until recently, however, there was no known way to render CMC lipids visible to microscopic observation. We solved this problem by preparing a smooth cross section of a single hair and subjecting it to argon sputter etching (ASE), followed by observation using scanning electron microscopy (SEM). We were able to discern a characteristic stitch pattern, and we also demonstrated that this pattern is related to the lipids in the CMC (J Cosmet Sci 56 (2005) 297). By visualizing the lipids in human hair through ASE-SEM, we will be able to clarify their microstructure and elucidate the role and functions of the CMC.

A scientific paper outlining these findings won the Joseph P. Ciaudelli Award for excellence among papers of Journal of Cosmetic Science 2005, dealing with hair care technology.