Funding sources None.
Depth profiling of stratum corneum biophysical and molecular properties
Article first published online: 26 APR 2011
© 2011 The Authors. BJD © 2011 British Association of Dermatologists
British Journal of Dermatology
Volume 164, Issue 5, pages 957–965, May 2011
How to Cite
Mohammed, D., Matts, P.J., Hadgraft, J. and Lane, M.E. (2011), Depth profiling of stratum corneum biophysical and molecular properties. British Journal of Dermatology, 164: 957–965. doi: 10.1111/j.1365-2133.2011.10211.x
Conflicts of interest None declared.
- Issue published online: 26 APR 2011
- Article first published online: 26 APR 2011
- Accepted manuscript online: 11 JAN 2011 12:38AM EST
- Accepted for publication 27 December 2010
Background The barrier function of the skin may be characterized by a number of biophysical and molecular methods. Variation in the barrier properties as a function of depth has not been explored in detail.
Objectives To characterize changes in corneocyte surface area, corneocyte maturity, selected protease activities and transepidermal water loss (TEWL) in the ventral forearm with increasing depth.
Methods The left mid-ventral forearm of 22 healthy volunteers was selected as the study site. After tape stripping, corneocyte maturity and surface area were assessed. The protease activity of the desquamatory kallikrein proteases, KLK5 and KLK7, and inflammatory tryptase was measured using a fluorogenic probe assay. Protein content and TEWL were also recorded.
Results Corneocyte maturity and surface area decreased with increasing number of tape strippings, i.e. depth into the skin. More mature corneocytes were typically larger than less mature corneocytes. The protease activities of both the desquamatory and inflammatory enzymes together with the protein content were highest in the outer layers of the stratum corneum and decreased with depth. As expected, TEWL increased as more stratum corneum layers were removed. There were no statistical differences between men and women or caucasian and black subjects for all of the parameters studied.
Conclusions The techniques used in this study provide rapid noninvasive measures of the spatial distribution of corneocyte maturity and surface area as well as protease activity and protein content within different levels of the stratum corneum layers. The methods used will allow mechanistic insight into the effects of formulation excipients and active ingredients on epidermal turnover and skin barrier function.