Engineering pliable, new vocal cord tissue to replace scarred, rigid tissue in these petite, yet powerful organs is the goal of a new University of Delaware (UD) research project. It is funded by a 5-year, $1.8 million grant from the National Institutes of Health's National Institute on Deafness and Other Communication Disorders.
Xinqiao Jia, UD assistant professor of materials science and engineering, is leading the project. Jia's research focuses on developing intelligent biomaterials that closely mimic the molecular composition, mechanical responsiveness, and nanoscale organization of natural extracellular matrices—the structural materials that serve as scaffolding for cells. These novel biomaterials, combined with defined biophysical cues and biological factors, are being used for functional tissue regeneration.
According to Jia, the vocal cords are more accurately defined as “vocal folds.” Each vocal fold is a laminated structure consisting of a pliable vibratory layer of connective tissue, known as the lamina propria, sandwiched between a membrane (epithelium) and a muscle. These flexible folds of tissue, coated in mucous to keep them moist, operate like an elevator door and must come together to produce a sound.
When you talk or sing, the folds may vibrate more than 100 times a second from the air that is forced up from the lungs through the trachea. However, excessive use or abuse of the voice can lead to scarring of the vocal fold lamina propria, which disrupts their natural pliability, resulting in hoarseness and other symptoms of vocal dysfunction.
“The combination of vocal fold fibroblasts, elastic and bioactive artificial extracellular matrices, and a dynamic bioreactor offers an exciting opportunity for in vitro tissue engineering of vocal fold lamina propria,” Jia noted.
Illustration: UD scientists Xinqiao Jia and Randall Duncan (co-investigator and senior mentor) are shown with the novel bioreactor that Jia designed. The device can simulate the demanding, high-frequency environment in which vocal cord cells live, vibrating back and forth at up to 100 hertz (100 times a second). --Kathy F. Atkinson.
University of Delaware Press Release (07/31/07)
Medical News Today (08/02/07)
Science Daily (08/03/07)