‘Pruney’ Skin Physics Revealed | Chemical & Engineering News
Volume 92 Issue 5 | p. 26 | Concentrates
Issue Date: February 3, 2014

‘Pruney’ Skin Physics Revealed

Drivers of skin swelling and shrinking are pinpointed by theoretical study
Department: Science & Technology
News Channels: Biological SCENE
Keywords: skin, keratin, water
[+]Enlarge
A lattice of interwoven keratin filaments swells in the presence of water.
Credit: Phys. Rev. Lett.
This image shows compact and swollen structures of keratin intermediate filaments in skin cells.
 
A lattice of interwoven keratin filaments swells in the presence of water.
Credit: Phys. Rev. Lett.

We’re all familiar with the wrinkled, “pruney” skin we get from spending too much time in a bath or pool. A theoretical study provides new details about what happens when our outer skin cells absorb water, causing skin to look shriveled (Phys. Rev. Lett. 2014, DOI: 10.1103/physrevlett.112.038102). The cells in that outer layer contain so-called keratin intermediate filaments that have a helical structure and are hydrophilic. The filaments are interwoven into an ordered, three-dimensional lattice. Studying the thermodynamics of water-induced filament lattice swelling, Myfanwy E. Evans of the University of Erlangen-Nürnberg and Roland Roth of the University of Tübingen, both in Germany, found that the swollen state sits in a global energy minimum: Given water, the lattice will expand, although there is a limit to how far the filaments will stretch. Unlike the hard keratin in hair and nails, the filaments in skin are not cross-linked and instead have a thin layer of water between them that serves as lubrication. As the structures absorb water and swell, the stretching of filaments induces tension, akin to stretching a spring. Consequently, only a small force, such as that provided by water evaporation, is necessary for the lattice to shrink back to its “dry” state.

 
Chemical & Engineering News
ISSN 0009-2347
Copyright © American Chemical Society

Leave A Comment

*Required to comment