Assessment of skin barrier function and biochemical changes of ex vivo human skin in response to physical and chemical barrier disruption

Topical dermatotherapy is intended to be used on diseased skin. Novel drug delivery systems even address differences between intact and diseased skin underlining the need for pre-clinical assessment of different states of barrier disruption. Herein, we studied how short-term incubation in culture media compared to incubation in humidified chambers affects human skin barrier function and viability. On both models we assessed different types and intensities of physical and chemical barrier disruption methods with regard to structural integrity, biophysical parameters and cytokine levels. Tissue degeneration and proliferative activity limited the use of tissue cultures to 48 h. Viability is better preserved in cultured tissue. Tape-stripping (50xTS) and 4 h sodium lauryl sulfate (SLS) pretreatment were identified as highly reproducible and effective procedures for barrier disruption. Transepidermal water loss (TEWL) values reproducibly increased with the intensity of disruption while sebum content and skin surface pH were of limited value. Interleulkin (IL)-6/8 and various chemokines and proteases were increased in tape-stripped skin which was more pronounced in SLS-treated skin tissue extracts. Thus, albeit limited to 48 h, cultured full-thickness skin maintained several barrier characteristics and responded to different intensities of barrier disruption. Potentially, these models can be used to assess pre-clinically the efficacy and penetration of anti-inflammatory compounds. (C) 2016 Elsevier B.V. All rights reserved.