A team at Massachusetts Institute of Technology (MIT) and Harvard Medical School, including an Indian-origin researcher, has developed a polymer gel that can mimic the vibrations of human vocal cords.
The gel, which could be implanted into scarred vocal cords to restore their normal functioning, could benefit millions of people with voice disorders.
Steven Zeitels, a professor of laryngeal surgery at Harvard Medical School, had started developing a new material that could be implanted into scarred vocal cords to restore them before singer Julie Andrews came to him seeking help in 1997.
The actress had lost her singing voice following surgery to remove noncancerous lesions from her vocal cords.
In 2002, he enlisted the help of MIT’s Robert Langer, the David H. Koch Institute Professor in the Department of Chemical Engineering, an expert in developing polymers for biomedical applications.
The team led by Langer and Zeitels has now developed a polymer gel with the help of former MIT researcher Sandeep Karajanagi, who is now an instructor of surgery at Harvard Medical School.
The team chose polyethylene glycol (PEG) as its starting material, in part because it is already used in many FDA-approved drugs and medical devices.
By altering the structure and linkage of PEG molecules, the researchers can control the material’s viscoelasticity.
For use in vocal cords, the researchers created and screened many variations of PEG and selected one with the right viscoelasticity, which they called PEG30.
In laboratory tests, they showed that the vibration that results from blowing air on a vocal-fold model of PEG30 is very similar to that seen in human vocal folds.
Also, tests showed that PEG30 could restore vibration to stiff, non-vibrating vocal folds such as those seen in human patients suffering from vocal-fold scarring.
Researchers hope to start testing of the gel in a small clinical trial next year.
The finding is published recently in the Annals of Otology, Rhinology and Laryngology.