Artificial Skin - Background

Background

The skin is the largest organ in the human body. Skin is made up of two layers, the epidermis and the dermis. The epidermis is the outer layer of skin that keeps vital fluids in and harmful bacteria out of the body. The dermis is the inner layer of skin that contains blood vessels, nerves, hair follicles, oil, and sweat glands. Severe damage to large areas of skin exposes the human organism to dehydration and infections that can result in death.

Traditional ways of dealing with large losses of skin have been to use skin grafts or from a different person/cadaver. The former approach has the disadvantage that there may not be enough skin available, while the latter suffers from the possibility of rejection or infection. Until the late twentieth century, skin grafts were constructed from the patient's own skin. This became a problem when skin was too far damaged or when too much of the organ was ruined.

Synthetic skin was invented by John F. Burke, chief of Trauma Services in Massachusetts General Hospital. He was assisted by Ioannis V. Yannas, a chemistry professor at Massachusetts Institute of Technology, Cambridge, Massachusetts. In the 1970s, they created a polymer with collagen fibers and sugar molecules. A small porous was formed. When the porous was placed on the wound, skin cells around it seemed to encourage a faster healing process. This allowed the healing process to continue at a much faster rate. They also created a skin from shark cartilage and cowhide. When this skin dried and was sterilized, it could be made into a thin membrane in which materials could pass through like with the original dermis. Silicon was then added to create a protective top layer to represent the epidermis. This added layer protected the new dermis as well as the inner fluids of the body. The synthetic dermis allowed blood vessels to grow, but couldn’t produce hair follicles or sweat glands.

In the late 1970s, medical researchers began experimenting with sheets of artificial skin that could be permanently grafted onto patients who have no other options. Two Boston surgeons discovered a successful new artificial skin design in 1981 that is known as Integra. Instead of replicating the function of healthy skin, Integra “tricks” real skin cells into growing a new dermis, which would replace the damaged dermis.