The ROC skin model: A robust skin equivalent for permeation and live cell imaging studies.

Rat epidermal keratinocyte (REK) Organotypic culture (ROC) is an epidermis model that is robust and inexpensive to develop and maintain, and it has in previous studies been shown to have permeability characteristics close to those of human skin. Here, we characterize the model further by structural comparison to native human and rat skin and by investigating functional characteristics of lipid packing, polarity, and permeability coefficients. We show that the ROC model has structural similarities to native human skin and observe human skin-like permeability coefficients for testosterone and mannitol.