Three-dimensional human tissue models of wounded skin.

Human skin equivalents (HSEs) are in vitro tissues in which a fully differentiated, stratified squamous epithelium is grown at an air-liquid interface on a Type I collagen gel harboring human dermal fibroblasts. HSEs now provide experimental human tissue models to study factors that direct re-epithelialization and epithelial-mesenchymal cross-talk following wounding. This chapter describes the fabrication of HSEs from human keratinocytes and fibroblasts and how HSEs can be modified to characterize the response of the human epithelium during wound repair. The protocols outlined first describe techniques for the generation of human tissues that closely approximate the architectural features, differentiation, and growth of human skin. This will be followed by a description of a protocol that enables HSEs to be adapted to monitor their response following wounding. These engineered human tissues provide powerful tools to study biological process in tissues that mimic the healing of human skin and of the epithelial tissue.