Skin wound healing in humans and mice: challenges in translational research

Skin, the first protective barrier of all animals, has evolved and specialized differently among fish, reptiles, birds and mammals[1]. Epidermis, the outermost layer, consists of a stratified squamous epithelium of keratinocytes delimited by the basal membrane, and contains melanocytes and Langerhans and Merkel cells. Dermis, the internal layer that provides structural integrity, elasticity, and nutrition, is a connective tissue composed by fibroblasts and extracellular matrix enriched in collagen and elastic fibers[2–4], and also contains blood and lymphatic vessels, sebaceous glands, sweat glands, nerve endings, and hair follicles invaginated from epidermis [5–7].