Vocal cords grown from human cells

Laboratory grown vocal cord tissue that produces realistic sounds is a step toward creating new vocal cords for patients suffering from diseases such as cancer or injuries that damage their voice. Vocal cords that produce voice sounds have been grown in the laboratory from human cells. Details of the research are reported in the journal Science Translational Medicine.

Investigators from the University of Wisconsin in Madison harvested connective tissue and lining cells from the vocal cords of four patients whose voice boxes had been removed for medical reasons, and one human cadaver. They grew those cells onto scaffolds that produced strong elastic tissue similar to the one in the natural voice box.  After two weeks of allowing the cells to grow in the laboratory, the cells assemble into layers that resembled the structure of healthy vocal cords.

To test the freshly-grown tissue folds, scientists implanted them into one side of voice boxes taken from dogs, and attached them to an artificial windpipe and blew humidified air through them. When air was blown over the tissue it vibrated, producing sounds that had the same characteristics as those made by natural dog vocal cords. High speed digital imaging showed that the cords vibrated like natural tissue too. In follow-up studies using mice the transplants tissue were not rejected during a three months follow-up.  It is unlikely that replacement voice boxes will be created from vocal cord tissue from patients with cancer.  However, vocal cords could be created from stem cells that are turned into muscle and lining cells to form the cords.

Laboratory grown replacements for damaged vocal cords are still years away and more research is needed in animals to show that they work well and do not provoke an immune response, and the process must be performed with clinical grade cells before the implants can be tried in humans.

Normal vocal cords