Human Skin Equivalent Model

Skin, the largest organ in the body, performs many important roles including protection against physical and chemical insults, regulation of temperature and fluid loss, and immunity and sensory roles. Once damaged, skin cannot perform these normal tasks and numerous complications such as infection or fluid loss can occur. To restore these roles, the body needs to close the wound as quickly as possible while retaining functionality and integrity. Our current understanding of the biological processes underlying wound closure, along with maintenance of skin function and integrity, is limited. This lack of fundamental knowledge has arisen in part from the less than ideal in vitro and ex vivo models available to facilitate skin research. For example, 2-dimensional (2D) in vitro cell culture studies do not accurately reflect the complex interactions that occur between the multiple cells present in the 3D in vivo skin environment. Similarly, in vivo studies in rodents and other small animals do not translate well to the human situation due to differences in anatomical structure, abundance of hair, and the fact these species are “loose-skinned” and heal wounds by contracture. In contrast, human skin heals via re-epithelialisation. The development of improved models is therefore critical to advancing our understanding of human skin repair, regeneration and maintenance processes.