Advanced

Stratum corneum molecular mobility in the presence of natural moisturizers.

Björklund, Sebastian LU ; Andersson, Jenny LU ; Pham, Dat LU ; Nowacka, Agnieszka LU ; Topgaard, Daniel LU and Sparr, Emma LU (2014) In Soft Matter 10(25). p.4535-4546
Abstract
The outermost layer of the skin, the stratum corneum (SC), is a lipid-protein membrane that experiences considerable osmotic stress from a dry and cold climate. The natural moisturizing factor (NMF) comprises small and polar substances, which like osmolytes can protect living systems from osmotic stress. NMF is commonly claimed to increase the water content in the SC and thereby protect the skin from dryness. In this work we challenge this proposed mechanism, and explore the influence of NMF on the lipid and protein components in the SC. We employ natural-abundance (13)C solid-state NMR methods to investigate how the SC molecular components are influenced by urea, glycerol, pyrrolidone carboxylic acid (PCA), and urocanic acid (UCA), all of... (More)
The outermost layer of the skin, the stratum corneum (SC), is a lipid-protein membrane that experiences considerable osmotic stress from a dry and cold climate. The natural moisturizing factor (NMF) comprises small and polar substances, which like osmolytes can protect living systems from osmotic stress. NMF is commonly claimed to increase the water content in the SC and thereby protect the skin from dryness. In this work we challenge this proposed mechanism, and explore the influence of NMF on the lipid and protein components in the SC. We employ natural-abundance (13)C solid-state NMR methods to investigate how the SC molecular components are influenced by urea, glycerol, pyrrolidone carboxylic acid (PCA), and urocanic acid (UCA), all of which are naturally present in the SC as NMF compounds. Experiments are performed with intact SC, isolated corneocytes and model lipids. The combination of NMR experiments provides molecularly resolved qualitative information on the dynamics of different SC lipid and protein components. We obtain completely novel molecular information on the interaction of these NMF compounds with the SC lipids and proteins. We show that urea and glycerol, which are also common ingredients in skin care products, increase the molecular mobility of both SC lipids and proteins at moderate relative humidity where the SC components are considerably more rigid in the absence of these compounds. This effect cannot be attributed to increased SC water content. PCA has no detectable effect on SC molecular mobility under the conditions investigated. It is finally shown that the more apolar compound, UCA, specifically influences the mobility of the SC lipid regions. The present results show that the NMF components act to retain the fluidity of the SC molecular components under dehydrating conditions in such a way that the SC properties remain largely unchanged as compared to more hydrated SC. These findings provide a new molecular insight into how small polar molecules in NMF and skin care products act to protect the human skin from drying. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Soft Matter
volume
10
issue
25
pages
4535 - 4546
publisher
Royal Society of Chemistry
external identifiers
  • pmid:24817485
  • wos:000337113100015
  • scopus:84902096162
ISSN
1744-6848
DOI
10.1039/c4sm00137k
language
English
LU publication?
yes
id
961b7678-0516-444a-8532-a97ad81ce983 (old id 4455364)
date added to LUP
2014-06-18 14:57:44
date last changed
2017-01-29 03:02:35
@article{961b7678-0516-444a-8532-a97ad81ce983,
  abstract     = {The outermost layer of the skin, the stratum corneum (SC), is a lipid-protein membrane that experiences considerable osmotic stress from a dry and cold climate. The natural moisturizing factor (NMF) comprises small and polar substances, which like osmolytes can protect living systems from osmotic stress. NMF is commonly claimed to increase the water content in the SC and thereby protect the skin from dryness. In this work we challenge this proposed mechanism, and explore the influence of NMF on the lipid and protein components in the SC. We employ natural-abundance (13)C solid-state NMR methods to investigate how the SC molecular components are influenced by urea, glycerol, pyrrolidone carboxylic acid (PCA), and urocanic acid (UCA), all of which are naturally present in the SC as NMF compounds. Experiments are performed with intact SC, isolated corneocytes and model lipids. The combination of NMR experiments provides molecularly resolved qualitative information on the dynamics of different SC lipid and protein components. We obtain completely novel molecular information on the interaction of these NMF compounds with the SC lipids and proteins. We show that urea and glycerol, which are also common ingredients in skin care products, increase the molecular mobility of both SC lipids and proteins at moderate relative humidity where the SC components are considerably more rigid in the absence of these compounds. This effect cannot be attributed to increased SC water content. PCA has no detectable effect on SC molecular mobility under the conditions investigated. It is finally shown that the more apolar compound, UCA, specifically influences the mobility of the SC lipid regions. The present results show that the NMF components act to retain the fluidity of the SC molecular components under dehydrating conditions in such a way that the SC properties remain largely unchanged as compared to more hydrated SC. These findings provide a new molecular insight into how small polar molecules in NMF and skin care products act to protect the human skin from drying.},
  author       = {Björklund, Sebastian and Andersson, Jenny and Pham, Dat and Nowacka, Agnieszka and Topgaard, Daniel and Sparr, Emma},
  issn         = {1744-6848},
  language     = {eng},
  number       = {25},
  pages        = {4535--4546},
  publisher    = {Royal Society of Chemistry},
  series       = {Soft Matter},
  title        = {Stratum corneum molecular mobility in the presence of natural moisturizers.},
  url          = {http://dx.doi.org/10.1039/c4sm00137k},
  volume       = {10},
  year         = {2014},
}