What makes the hair so strong?
Research & Innovation

Hair Resistance Outside

The answer is in a recent publication of a transdisciplinary team of L’Oréal and University Paris-Sud Solid Physics Laboratory in PNAS “Keratin network modification lead to the mechanical stiffening of the hair follicle fiber”.

This paper unveils a deeper understanding of mechanics of hair and reveals its dynamic supramolecular organization.

The hair fiber is endowed with unique mechanical property that is resistance to breakage and elongation. 
 
To understand the origin of this unique mechanical property, a transdisciplinary team of L’Oréal investigated the progressive maturation of the hair fiber, starting from the lower bulb.
 
Using atomic force microscopy the progressive organization of keratin microfibril network was evidenced, with concomitant increase in diameter of keratin microfibril, the continuous compaction and increasingly parallel orientation. Together with progressive biological supramolecular organization, a progressive mechanical stiffening of the fiber was recorded.
 
This study confirmed that keratin microfibril network is first likely stabilized by isopeptide bonds and in 2nd step by cysteine cross-linking network.
 
This study will give clues to further identify and design active compounds, aimed at modulating hair fiber mechanical properties.

Read the full publication here: http://www.pnas.org/content/113/21/5940.long
 
Learn more about our Hair research and contribution to the latest World Hair Congress: http://www.congress.loreal.com/2015-whrc.php

About PNAS Proceedings of the National Academy of Science http://www.pnas.org/site/aboutpnas/index.xhtml