Vocal cords are small and complex — and, when badly damaged, they're difficult to treat.
Now, scientists at the University of Wisconsin-Madison have engineered lab-grown vocal cord tissue for the first time.
The tissue appears to be functional, the researchers report, although so far it has only been tested outside of an animal's body.
The Associated Press explains the researchers' process:
Welham's team started with some rare donations of vocal cords from four patients who had had their larynx removed for non-cancerous reasons, and from one deceased donor. The researchers culled two types of cells that made up most of the tissue, and grew a large supply of them.
Then they arranged the cells on 3-D collagen scaffolding, and the two cell types began mixing and growing. In 14 days, the result was tissue with the shape and elasticity of human vocal cords, and with similar chemical properties.
But could it work? To tell, the researchers turned to a technique that sounds, well, strange but is a staple in voice research. They took a larynx that had been removed from a large dog after its death and attached it to a plastic "windpipe" that blew in warm air to simulate breath. ... The researchers cut out one of the native canine vocal folds and glued a piece of the new bioengineered tissue in its place.
The result was a buzzing sound, "almost like a kazoo," the AP reports — approximately the same sound that the original dog larynx made under the same conditions, which suggested the possibility of lab-grown vocal cords working inside a body.
Vocal impairment, either temporary or permanent, affects about 20 million people in the U.S. at any given time, reports Science. Vocal cords that have been scarred by surgery or radiation are particularly difficult to treat. People with that kind of damage could benefit from a lab-grown replacement, especially if such a surgery would require fewer immunosuppressants than receiving cords from cadavers, as Wired reports.
But the researchers note that the engineered tissue is still in the early research stages, and significant more study is required before the tissue can be tested in humans.