Tissue Engineering of Skin

Abstract

This chapter explores the functions of the skin and injury responses, explains the role of tissue engineering (TE) in healing the skin, and discusses currently available technologies. The mature epidermis is composed primarily of keratinocytes arising from a layer of basal cells situated on the basement membrane. As the keratinocytes differentiate they form a stratified squamous epithelium. As the cells undergo terminal differentiation they lose their nuclei and form a highly cross-linked protein-based layer of keratin. The dermis is mainly connective tissue, predominantly collagen, with elastin seen in the superficial papillary dermis. The essential factors to achieve healing are a source of cells capable of differentiating into the tissue and an extracellular matrix capable of supporting the cells. The practice of tissue expansion is a well-established surgical tool for the development of skin by subcutaneous insertion of inflatable devices in vivo, which can be serially enlarged with the resulting development of the skin as demonstrated by cell proliferation. The tissue-expanded skin has all layers and the complete characteristics of the donor site including retention of functional innervation. The process of harvesting cells from the dermal-epidermal junction by enzymatic and physical dissociation is used for immediate delivery of a noncultured cell population to the wound. The maintenance of the melanocytes allows the development of appropriate pigmentation. The cells adhere, migrate, and proliferate across the wound surface and then differentiate and self-organize into a mature epidermis.