title: Effect of detergents on the physicochemical properties of skin stratum corneum: a two-photon excitation fluorescence microscopy study.
abstract: OBJECTIVE
  Understanding the structural and dynamical features of skin is critical for advancing innovation in personal care and drug discovery. Synthetic detergent mixtures used in commercially available body wash products are thought to be less aggressive towards the skin barrier when compared to conventional detergents. The aim of this work is to comparatively characterize the effect of a mild synthetic cleanser mixture (SCM) and sodium dodecyl sulphate (SDS) on the hydration state of the intercellular lipid matrix and on proton activity of excised skin stratum corneum (SC).
  
  
  METHODS
  Experiments were performed using two-photon excitation fluorescence microscopy. Fluorescent images of fluorescence reporters sensitive to proton activity and hydration of SC were obtained in excised skin and examined in the presence and absence of SCM and SDS detergents.
  
  
  RESULTS
  Hydration of the intercellular lipid matrix to a depth of 10 μm into the SC was increased upon treatment with SCM, whereas SDS shows this effect only at the very surface of SC. The proton activity of SC remained unaffected by treatment with either detergent.
  
  
  CONCLUSIONS
  While our study indicates that the SC is very resistant to external stimuli, it also shows that, in contrast to the response to SDS, SCM to some extent modulates the in-depth hydration properties of the intercellular lipid matrix within excised skin SC.
authors: Membrane Biophysics and Biophotonics Group/MEMPHYS-Center, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230, Odense M, Denmark.
authors: M
authors: M
authors: Bloksgaard
authors: Membrane Biophysics and Biophotonics Group/MEMPHYS-Center, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230, Odense M, Denmark.
authors: J R
authors: JR
authors: Brewer
authors: Unilever R&D, 40 Merritt Blvd., Trumbull, CT, 06611, USA.
authors: E
authors: E
authors: Pashkovski
authors: Unilever R&D, 40 Merritt Blvd., Trumbull, CT, 06611, USA.
authors: K P
authors: KP
authors: Ananthapadmanabhan
authors: Department of Plastic Surgery, Odense University Hospital, DK-5000, Odense C, Denmark.
authors: J A
authors: JA
authors: Sørensen
authors: Membrane Biophysics and Biophotonics Group/MEMPHYS-Center, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230, Odense M, Denmark.
authors: L A
authors: LA
authors: Bagatolli
mesh_terms: D003902:Detergents / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D050356:Lipid Metabolism; D008856:Microscopy, Fluorescence / Q000379:methods*; D019301:Oleic Acid / Q000494:pharmacology; D017785:Photons; D012879:Skin Physiological Phenomena / Q000187:drug effects*; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology
chemical_list: D003902:Detergents; D019301:Oleic Acid; D012967:Sodium Dodecyl Sulfate
keywords: LAURDAN generalized polarization; detergents; fluorescence lifetime imaging; multiphoton excitation fluorescence microscopy; skin barrier; transdermal pathways