DEVELOPMENT OF AN IN VITRO MODEL FOR THE PREDICTION OF SKIN IRRITATION POTENTIAL.

• TR Number: 145
• Authors: Bernhofer, L.P., Seiberg, M., Martin, K.M. Johnson & Johnson Consumer Products Worldwide, Skillman, NJ 08558.

Cytokines important to the inflammatory cascade were measured both at the level of transcription and secreted protein, from skin equivalents topically exposed to a panel of relevant consumer products. The response of a full thickness model, consisting of both keratinocytes and fibroblasts (Advanced Tissue Sciences’ SKIN2™), was compared to a keratinocyte only equivalent (Mattek’s Epi-Derm™) and to a co-culture model consisting of EpiDerm underseeded with dermal fibroblasts. Our results show that various materials trigger the release of different cytokine profiles from skin equivalents. This suggests that there are many mechanisms inducing irritation and modeling these, across product classes, in a simple system is problematic. The cytokine profile is also dependent on the model used, suggesting that some skin equivalents may be more appropriate for certain applications than others. We show that systems can be developed that are highly specific for a particular product class. For example, the measurement of IL-1ra from an epidermal equivalent seems to be useful for the prediction of surfactant based irritation.