Bioengineered skin was developed because of the need to cover extensive burn injuries in patients who no longer had enough skin for grafting. Not so long ago, a patient with third degree burns over 50% of his body surface usually died from his injuries. That is no longer the case. Today, even someone with 90% TBSA has a good chance of surviving. With the array of bioengineered skin and skin substitutes available today, such products are also finding use for chronic wounds, in order to prevent infection, speed healing and provide improved cosmetic results.
Skin used in wound care may be autograft (from the patient’s own body, as is often the case with burn patients), allograft (cadaver skin), xenogeneic (from animals such as pigs or cows), or a combination of these. Bioengineered skin substitutes are synthetic, although they, too, may be combined with other products. It consists of an outer epidermal layer and (depending on the product) a dermal layer, which are embedded into an acellular support matrix. This product may be autogenic, or from other sources. Currently most commercial bioengineered skin is sheets of cells derived from neonatal allogenic foreskin. This source is chosen for several reasons: because the cells come from healthy newborns undergoing circumcision, and therefore the tissue would have been discarded anyway; foreskin tissue is high in epidermal keratinocyte stem cells, which grow vigorously; and because allergic reactions to this tissue is uncommon.
Selected Bioengineered Skin & Skin Substitutes