The science fiction image of organs growing in vats may not remain fiction much longer.
One of the most promising areas of research to utilize stem cell technologies is tissue engineering, in which researchers work to “build” new tissues that can be used to reconstruct or replace damaged body parts.
“Unlike a damaged car, a damaged person can’t just be rebuilt using spare parts, but that could be changing soon,” said Dr. Antonios Mikos, associate professor of biological and chemical engineering at Rice University and tissue engineering researcher.
In 1986, Dr. Joseph Vacanti and Dr. Robert Langer developed the method now used in most tissue engineering projects. A biodegradable polymer is shaped into a scaffold in which stem cells are nurtured and grown.
The whole structure of cells and scaffold is transplanted into a patient. As the cells replicate and form new tissue, the polymer breaks down, leaving only the new tissue or organ, indistinguishable from its surroundings.
Today, doctors can treat victims of severe burns with lab-grown skin taken from a plastic bag. In other cases, patients have had cartilage grown and implanted into knees and other joints.
Meanwhile, Mikos and his team are working to develop bone tissue. Unlike skin and cartilage, bone requires an extensive blood supply, something which is proving difficult to create in engineered tissue.
Mikos is making progress, however, and he has now developed mature bone tissue in a matrix that was inserted into a sheep ribcage.
Other researchers have already grown simple organs such as bladders, and an international consortium of scientists known as Living Implants from Engineering, or LIFE,, has vowed to grow human hearts within the next decade.
The heart will probably be grown in four parts – valve, muscle, blood vessels, and conduits -and then brought together.
Researchers have already created rudimentary blood vessels, heart valves and heart muscles.
For now, the biggest limiting factor for tissue engineering may
be money.
The LIFE heart initiative alone is expected to need $5 billion in research funding.
But even as a new field with limited funds, encouraging results are being reported.
“I really feel that it’s not unrealistic to say that we will eventually be able to recreate any organ,” Mikos said. “This is the beginning of a field that will change the way medicine is done.”