Skin Grafts

Artificial Skin Grafts

In extreme burn cases, where 80 or 90 percent of a victim's body is scorched by second- and third-degree burns, there often isn't enough healthy donor skin available to perform an autograft. Beginning in the late 1970s, medical researchers began experimenting with sheets of artificial skin that could be permanently grafted onto patients who have no other viable option.

As we explained in the article, How Lab-grown Skin Works, two Boston surgeons debuted a successful new artificial skin design in 1981 that's now known as Integra. Interestingly, Integra technically isn't "artificial skin." Instead of replicating the function of healthy skin, Integra "tricks" real skin cells to grow in the damaged dermis.

Integra functions as artificial "scaffolding" around which new skin cells can grow. The scaffolding is made of shark cartilage and cow-derived collagen, the protein found in all connective tissue. The bottom layer of the collagen scaffolding -- the part that makes contact with the wound surface -- is covered with a sugar molecule called glycosaminoglycan. The sticky sugar coating mimics the texture of the lower surface of the dermis [source: NIGMS].

Apparently, this texture is enough to trick skin cells in the body called fibroblasts to start generating human collagen on contact. As the body produces more and more collagen, the connective tissue begins to work its way up the artificial scaffolding, slowly building a new dermis. Meanwhile, the artificial scaffolding simply dissolves away, leaving no trace of the implant.

Integra does not replace the epidermis. Instead, the product comes with a thin silicon coating that can be pealed away once the dermis has fully regenerated. To replace the epidermis, doctors rely on lab-grown skin. They examine a piece of skin from the patient and place it in a culture spiked with mouse-derived fibroblasts. Over the course of a few weeks, the fibroblasts generate a thin sheet of epidermis that can be placed over the new dermis.

The latest breakthroughs in artificial skin point to full skin replacements -- epidermis, dermis and even blood vessels -- grown entirely in the lab. A German company has successfully grown bi-layer skin samples (both epidermis and dermis) in a lab and California researchers have successfully grown blood vessels from a skin sample [sources: Maugh and ScienceDaily]. Scientists hope to produce a fully-functional, lab-produced artificial skin graft in the near future.

For lots more information on amazing medical procedures and the science of skin, take a look at the links on the next page.