A schematic diagram of a desirable full-thickness TES. (a) The relatively thin keratinized epidermal layer provides protective function that prevents infection and fluid loss. (b) A much thicker dermal layer underlies the upper layer and consists of abundant mesenchymal cells and ECM proteins, forming the basal body of TES. (c) To increase the survival of TES, a well-vascularized layer containing nerve receptors should be integrated under the dermal capillary network. (d) Skin appendages including hair follicles and sweat glands embedded in the dermal layer are also indispensable parts of full-thickness TES that best mimic the function as well as appearance of normal skin.