Claudia Castillo, whose lungs had been ravaged by tuberculosis, has a new trachea. She made it herself . . . sort of.

Doctors in Spain took stem-cells from Claudia Castillo's bone marrow and had them form a section of trachea based on the trachea of an organ donor. The scientists transplanted the 2.75-inch piece and published the results in The Lancet:

The graft immediately provided the recipient with a functional airway, improved her quality of life, and had a normal appearance and mechanical properties at 4 months. The patient had no anti-donor antibodies and was not on immunosuppressive drugs.

The results show that we can produce a cellular, tissue-engineered airway with mechanical properties that allow normal functioning, and which is free from the risks of rejection.

Castillo is the first person to have an engineered trachea transplant, The Guardian says. She has had her new windpipe for several months without immunosuppressants - a breakthrough in surgery.

Besides giving hope to those who need transplants, Castillo's case is also important to the debate over whether to allow stem-cell research which destroys embryos.

"Engineering new tissues and organs from stem cells has long been a goal of researchers, because it would help overcome a chronic shortage of donor organs." NPR says. "But controversies over the source of stem cells have slowed research in the United States."

However the transplant, rather than highlighting limitations, is another victory for ethical (and legal) stem-cell research. In its Q&A on stem-cells, CNN says "In the past, because adult stem cells were considered stuck in their ways, the focus had been on embryonic cells but now scientists and doctors will be wanting to see if adult cells can be used to treat a wider range of conditions."