In vivo investigation of the evolution of skin barrier repair after mechanical injury

Abstract

The stratum corneum (SC) serves a primary function of skin barrier and its maintenance is vital for the existence of terrestrial life. Few studies have been performed for evaluation of human SC repair in vivo, non-invasively. In the present study tape stripping was performed on the arms and legs of seven volunteers until all the SC was removed. The injured site and a control adjacent site were measured over a period of 10 days after the injury to assess functionality and repair. Transepidermal water loss (TEWL), tryptophan fluorescence and reflectance confocal microscopy were used to determine permeability of the skin barrier, cell turnover and epidermis morphology, respectively. The results show an exponential rate of recovery for the skin permeability (TEWL) which contrasted with a linear increase in the thickness of the SC as determined by confocal microscopy. Cell turnover increased rapidly immediately after the injury to 2.5 times the levels of the control site, attaining a maximum of 3.5-4 times greater levels after three days and slowly returned to baseline levels after the ten days. Correlation of the cell turnover to the thickness of the viable epidermis was observed and further studies are under way to interpret these results.