( s of pregnant women elect to have amnio...)Cells from amniotic fluid used to tissue-engineer a new trachea

"In many cases, the amniotic fluid is collected anyway," says Fauza. "It's a precious resource that's thrown out now, but shouldn't be."

Less than two tablespoons of amniotic fluid provide enough fetal cells to repair a malformation in utero or after birth potentially, even years later, Fauza says. He envisions a future in which amniotic fluid is banked for everyone's use. "Fetal cells are the best cells you can have for tissue engineering," he says. "They grow very well, and they're very plastic you can coach them to do what you want."

Last year, Fauza reported using similar techniques in newborn lambs to repair congenital diaphragmatic hernia (CDH), or a hole in the diaphragm that separates the lungs from the visceral organs. If the hole is large enough, the stomach and other visceral organs can end up in the chest cavity, crowding the lungs and stunting their growth. Using mesenchymal stem cells from amniotic fluid, Fauza's team engineered a tendon patch for the diaphragm; a year later, the lambs' diaphragms showed good healing.

The FDA is now reviewing Fauza's application to conduct a clinical trial in human babies with a prenatal ultrasound diagnosis of CDH; the amniotic fluid would be collected several months before birth and a tissue-engineered patch made ready for use soon after delivery. His team is also working on stem-cell-based, tissue-engineered grafts to fix spina bifida (in which the spinal column doesn't close fully during fetal development) and structural cardiac defects, using similar principles.