Vocal Cord Tissue Grown in Lab
Scientists at the University of Wisconsin-Madison say they've been able to grow vocal cord tissue in a lab--tissue that can produce sound when grafted on to an artificial windpipe.
In addition, noted the bioengineers who worked on the project, the cords, which were created from human tissue, also were not rejected by the body when transplanted into mice with “humanized” immune systems.
Current estimates are that 7.5 million people in the U.S. have trouble using their voices, as nerves become damaged from injury, surgery, viral infection or cancer. Collagen injections and other materials are currently used to help temporarily restore vocal cord mucosal linings, but there's still no solution for those who have suffered nerve damage or have had their vocal cords removed.
For this project, vocal cord cells were isolated from a deceased person, purified, and then grown in layers on a 3-D collagen scaffold. It was similar to the process used to make artificial skin. Within two weeks,the tissue was strong, flexible, and held many of the same qualities and proteins as healthy vocal cord tissue.
Scientists transplanted the tissue into voice boxes of cadaver dogs, with the lab grown tissue on one side and natural tissue on the other. The tissue not only produced sound, but vibrated in a similar way to the natural vocal cords. The lab-grown cords even began to grow the same protective membrane normally found on healthy cords.
The researchers acknowledged that they still have a long way to go before such tissues can be transplanted into humans. But the research offers hope that one day those who’ve lost their voices can have them restored.