Researchers in Boston have discovered a gel that could repair vocal cord damage and help people with hoarse voices to be heard again.
The artificial vocal cord material replaces a layer of the vocal structure to restore flexibility, allowing the vocal folds to vibrate more easily, which creates sound, said Dr.Steven Zeitels, director of the Center for Laryngeal Surgery and Voice Rehabilitation at Massachusetts General Hospital. He hopes for the biomaterial developed and tested with MIT chemical engineering professor Robert Langer to reach human trials next year.
Vocal chords can develop scarring a number of ways, including cancer and overuse from singing, but it can also come from normal wear and tear, such as shouting over a group of students every day in a classroom, Zeitels said.
"There's probably no part of the human body that sees more trauma in a lifetime," Zeitels said, adding that when he measured Steven Tyler's vocal cords during a concert in 2007, his vocal cords collided 7,800 times.
The vocal cords, or folds, are made up of three layers: a surface layer, the middle layer (gelatinous) and the deepest layer (muscle), said Dr. Milan Amin, who was not involved in Zeitels' research, but is the director of New York University's Voice Center. When the middle gel-like layer is damaged, the top layer sticks to the bottom layer and interrupts vibration, causing hoarseness, he said. This is called vocal scarring.
Zeitels said he hopes to inject the gel into the vocal folds' outer membrane to decrease stiffness from scarring. It would have to be replaced, but he hopes it will be long-lasting.
The throat surgeon treated singer Adele last year when she came to him with vocal bleeding, and Major League Baseball announcer Joe Buck, when a virus paralyzed his vocal nerve last spring. He also became Julie Andrews' doctor after a routine surgery ruined her famous singing voice in the 1990s.
But Zeitels said the gel, which he developed with MIT chemical engineering professor Robert Langer, won't make Julie Andrews sing like she did in "The Sound of Music" just yet. To restore vocal ranges like Andrews', he'll need an even more advanced gel, "the perfect material."
"Singers won't get this for ages," Zeitels said. "We have to fix the cancer patients first."
Roger Egan, an executive at open source company Red Hat, said he knows how important these treatments can be for cancer patients firsthand. He was diagnosed with vocal cord cancer in March.
Zeitels used laser technology to cut out the cancer and then injected fat from Egan's stomach into the middle layer of his vocal cords, where the gel would go, making it possible for him to speak again.
"If you had talked to me six weeks ago, it was an audible whisper," Egan said. "This is pretty personal. ... You don't know how valuable it is."
Egan said he may be a candidate for the gel when the fat needs to be replaced.
But given that the gel has not yet been tested on humans, it's not clear whether it will become a treatment for scarring at all.
Amin said even the most promising vocal scarring treatments can be problematic in human trials. It's hard to simulate human vocal cords in mammalian lab experiments because they're so unique, he said.
"We don't know yet," Amin said of whether Zeitels' gel will work. "The thing with treatments for scarring on the vocal cords is that many things have been developed over many years. They always look very promising in research."