TOMA Foundation for Burned Children

Skin Cloning

A California company is creating a new generation of spare body parts. Not by building them but by growing them in a laboratory. Jesus Segovia was burned in a gas fire last November. His wounds have healed well thanks, in part, to man made skin. John Hansbrough, M.D., UCSD Medical Center, San Diego: "We used this to place on the wounds in the operating room and it functioned as a temporary skin replacement for several weeks while the patient could be brought back and stabilised."

The manmade skin starts as a soupy mixture containing skin cells from the donated foreskins of new-borns. The mixture is pumped onto a plastic mesh scaffold. In seven days, the cells multiply and fill in the scaffold to produce a layer of skin. The skin can be grown in the lab to any size. Gail Naughton Ph.D., Dermagraft: "From one donor material, we can get 250,000 square feet of final product." The product, known as Dermagraft is sterile, so patients face fewer problems with infection and rejection that often occur with cadaver skin grafts John Hansbrough, M.D.: "They may reject that skin in a couple of weeks and have to go back to surgery just to have that skin replaced." In a study of 85 burn patients treated with Dermagraft, the need for surgery was cut in half, and hospital stays were shortened by months. But what does manmade skin feel like? Jesus Segovia, Burn Victim: "I feel the same like I did before. I feel that I never use another skin."

As Jesus healed, the dermagraft was replaced with Healthy skin from his back and legs. Dermagraft’s creators hope to engineer a permanent skin the may someday eliminate the need for human skin grafts. Also in the works, a permanent tissue plug for diabetic foot ulcers, man made cartilage and heart valves. All are currently in clinical studies.

BACKGROUND:

THE SEARCH FOR SKIN:
Millions of Americans suffer organ and tissue loss every year from accidents, birth defects and diseases such as cancer. Of the 2,000,000 serious burn victims in the United States each year, as many as 15,000 need skin grafts. The American Red Cross estimates that only one-sixth of the skin needed for burn victims is available from the nation’s tissue banks.

The donor cadaver skin that is available comes with plenty of complications. It can cost as much as $1,000 a square foot, and comes in thin strips that must be pieced together like a patchwork quilt. Cadaver skin also carries the risk of harbouring viruses including HIV.

CLONING HUMAN TISSUE:
Advanced Tissue Sciences, a tissue engineering company in La Jolla, California, has developed core technology to manufacture human tissues and organs for transplantation. The company uses human cells to develop safer, more cost effective alternatives to currently available treatments.

Dermagraft is a sheet of human dermal tissue, combined with a honeycombed synthetic mesh that acts as the epidermal or upper layer of skin. It has been successfully used as a transitional covering for severely burned patients. Cells called fibroblasts are taken from the foreskins of new-borns, discarded during circumcision. One donor foreskin contains enough material to grow 250,000 square feet of skin. The final product can be stored at -70 degrees for up to a year.

ADVANTAGES TO USING THIS TYPE OF SKIN:
Readily accessible for emergency burn treatment, Sterile, No risk of rejection by surrounding tissue, Can be grown and tailored to fit any size burn.

RESULTS:
Ten patients were enrolled at three burn centers. Each version was placed over a deep partial or full thickness burn. The grafts were left for 28 days. At Day 14, 98% of the wounds were covered with the new skin. All wounds were 100% closed in 21 days. The FDA is presently reviewing the treatment.

OTHER USES:
Other people who may benefit from Dermagraft are the 2.6 million people who suffer from chronic, slow-healing or non-healing skin ulcers. A piece of the skin would be plugged into the wound to promote the overgrowth of the patient’s own skin.

FOR MORE INFORMATION, PLEASE CONTACT:

Marie Burke,
Advanced Tissue Sciences, 10933 North Torrey Pines Road, La Jolla, CA 92037, 450-5802

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