Artificial skin offers promise, but so far little reward

BOSTON -- For many of the badly burned survivors of the Rhode Island nightclub disaster, the best hope for a successful recovery may lie in a substance that is manmade and half-alive.

Artificial skin nurtures the body's own skin cells, sometimes even deceiving them as they struggle to grow and replace burned tissue. The technology is promising -- but doctors warn it's costly and not always completely effective.

Covering a patient who is 50 percent burned can require $50,000 worth of the material, said Dr. Paul Taheri, director of the University of Michigan Trauma Burn Center. The new skin also remains vulnerable to infections.

"While it's awfully useful, it's not the thing that we hoped: to be able in one setting to completely replace skin that has burned," said Dr. Colleen Ryan, a co-director of the burn unit at Massachusetts General Hospital.

"It's never like God made it again," she added.

The Feb. 20 fire at The Station nightclub in West Warwick, R.I., killed 98 people and injured more than 180, many of whom were critically burned. Investigators believe a rock band's pyrotechnics ignited polyurethane foam used for soundproofing, causing the fast-moving blaze.

Burned, dead skin must be replaced with something that does everything the old skin did: regulate temperature, keep in fluids and keep out invaders like bacteria.

One option is to move a thin layer of healthy skin from elsewhere on the body to cover the burn. But if more than 50 percent of the body is burned, there obviously isn't enough healthy skin. Skin from cadavers can help temporarily, but after a few weeks will be rejected by the body's immune system.

Mixed success

Two companies that have attempted to market artificial skin have had mixed success.

San Diego-based Advanced Tissue Sciences Inc., the maker of one leading product called TransCyte, has been forced to turn production over to British firm Smith & Nephew after filing for bankruptcy protection.

The other leading product, Integra, by Integra LifeSciences of Plainsboro, N.J., reported record fourth-quarter profits last month, but its artificial skin product accounts for only $4.3 million of the company's $117.8 million in annual revenue, estimates First Albany analyst William J. Plovanic.

"There's a big difference between a good technology and a good business," Plovanic said.

TransCyte helps repair the upper, or epithelial, layer of skin, while Integra is used to reconstruct the lower layer, called the dermis.

TransCyte contains skin cells called fibroblasts, which act as a kind of skin stem cell, growing, if conditions allow, into the variety of tissues that comprise healthy skin.

But they don't just grow; they need something to cling to, and TransCyte is made of a kind of scaffolding, not unlike a garden lattice that encourages vines to grow up around it.

Patients with third-degree burns, however, may require Integra to replace the dermal skin layer. It also provides a kind of scaffolding that helps the dermis regenerate itself, in part by tricking it into thinking there are healthy epithelial cells above it.

Ryan and others recently completed the first major post-approval study on Integra's efficacy and found its median success rate was 95 percent, though 13 percent of patients experience some kind of infection.

Whether artificial skin actually saves lives is unclear, but for burn victims at particular risk -- the elderly or those with burns covering 40 percent or more of the body -- it appears to shorten hospital stays.

"This is version one," Taheri said. "My view is, sit tight, as we get more experienced and more knowledgeable, version four will be pretty good."

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On the Net

TransCyte: www.smith-nephew.com/businesses/W_TransCyte.html

Integra: www.integra-ls.com/index_java.html