Micro-PIXE characterization of different skin models

Because of the large natural inter-individual variability and of some difficulties in obtaining material from surgery or from healthy volunteers, the use of human native skin in experimentation comes up against fierce competition from experimental models, such as reconstituted epidermis or human skin grafted in animals. In this study, micro-PIXE was used in association with other ion beam microanalysis techniques to characterize different epidermis models on a microscopic scale. The ionic species were found to be highly compartmentalized in the different strata of human skin with a distribution that can be explained in the frame of the homeostatic barrier function. Reconstituted epidermis obtained from airlifted culture, epidermis of mice foot sole and human forehead skin grafts transplanted into mice are the models investigated and compared with human native skin. Very similar inorganic ion patterns were observed in all epidermis, suggesting comparable permeability barrier mechanisms and validating their use as alternative approaches to native skin experimentation. In the near future, we plan to use some of these models in penetration studies and for investigating effects of exposure to different environmental stresses. Copyright (c) 2005 John Wiley & Sons, Ltd.