Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: FRIDAY, October 20, 1995 TAG: 9510200062
SECTION: NATIONAL/INTERNATIONAL PAGE: A-1 EDITION: METRO
SOURCE: ROBERT S. BOYD KNIGHT-RIDDER/TRIBUNE
DATELINE: WASHINGTON LENGTH: Medium
The idea is to use living cells to reconstruct lost or damaged tissues instead of replacing them with artificial products made of metal, ceramics or plastic.
``We want to build on the body's own natural healing processes,'' said Linda Cima, a chemical engineer at the Massachusetts Institute of Technology, who is building a substitute liver out of real veins, arteries and liver cells.
This grow-your-own-organ approach - a marriage of biology, chemistry and physics - is called ``tissue engineering.'' Along with gene therapy, it is a hot spot for researchers on the frontiers of health care.
If successful, tissue engineering ``will forever change the medical landscape,'' predicted Harold Alexander, head of the Department of Bioengineering at the Hospital for Joint Diseases in New York City.
For example, U.S. surgeons currently perform more than 1 million operations a year to replace torn or missing cartilage, using artificial metal or plastic prostheses. The devices often fail or have unpleasant side effects.
In experiments on animals, tissue engineers take a small piece of cartilage, say from a rabbit's knee, grow it in the laboratory on a temporary ``scaffold'' of a biodegradable material, and re-implant it in the knee.
``Some day we'll be able to replace a whole joint with nothing but human tissue,'' said Gail Naughton, president of Advanced Tissue Sciences Inc. of La Jolla, Calif.
By the end of the decade, according to Alexander, natural replacements will be attempted for knee and hip joints, tendons and ligaments, heart and blood vessels, livers, pancreases, kidneys and intestines.
For some people, tissue engineering might be a matter of life or death. Robert Langer, a professor of chemical and biomedical engineering at MIT, said 30,000 Americans died for lack of a liver transplant last year. Fewer than 3,000 liver donors were available.
Even advocates of tissue engineering caution that their science is in its infancy and success is not guaranteed. Most of the products under development are still being tested in laboratory dishes or on animals. Only a few human trials are under way, and the results are mixed.
``We have to have reasonable expectations,'' said Peter Eisenberger, a Princeton University materials scientist and co-chairman of a workshop on tissue engineering sponsored by the National Institutes of Health this week.
Despite the uncertainties, the NIH is spending $90 million a year on tissue engineering. The Food and Drug Administration, which is responsible for the safety of medical devices, also supports this emerging technology.
``In the next few years, I'm confident we are going to see such products'' in medical practice, said Dr. Kiki Hellman, the FDA's manager of biotechnology products. ``The human trials are very encouraging.''
One reason for the government's enthusiasm is that tissue engineering eventually could lower the cost of health care by reducing the need for expensive surgery and hospitalization. By some estimates, organ and tissue loss cost as much as $400 billion a year.
by CNB