Researchers Score Advance in Quest to Grow Replacement Organs

But the Massachusetts team, according to the Globe, has grown a new circulatory system to feed the organs. They created a vast network of tiny plastic tubes, many smaller than a human hair, and then coaxed cells to line the insides and form a network of live capillaries. The plastic tubes would ultimately dissolve in the body.

To create a liver, the team would alternate thin layers of capillary networks with thin layers of liver cells.

Recently, the Globe reported, the team has had several successes, including an experiment that showed the capillaries could successfully handle blood flow from a living rat for hours.

The new blood vessels are the product of the Center for Integration of Medicine and Innovative Technology, an unusual collaboration that coordinates the work of doctors, chemists, physicists, and engineers.

''This would not be possible without a team that came together across disciplines,'' said Jeffrey T. Borenstein, a physicist at Draper Laboratory who builds the tiny tubes where the capillaries grow.

Dr. Joseph P. Vacanti, a pediatric transplant surgeon at Massachusetts General Hospital who leads the team, said the researchers have yet to implant the capillaries into an animal to show they can keep tissue alive.

While he expressed optimism, Vacanti also emphasized that the technology is still years from helping patients.