Tissue engineering of the human vocal folds
Dr. Titze is joined by research scientists and students at The University of Iowa (Sarah Klemuk, Xiaoying Lu and Sanyu Jaiswal) and by collaborators at the University of Wisconsin (Dr. Susan Thibeault) to study the effects of vibration on vocal fold tissues. Much of the work will soon also be conducted in the new Tramway facility in Denver.
Synthetic materials (like sponges and foams) are used to begin the engineering process. These materials, which are porous, are seeded with cells that produce their own products (various protein fibers and fluid-like protein substances) to fill the spaces in the sponges or foam. All of this is happening in a so-called bioreactor, which is a device that allows cells to react to imposed environmental forces (Figure 1). In this case, the forces are vibrational forces. The tissue is cultured between two plates (see Figure 2), like a hamburger patty between two buns. One of the plates rotates back and forth at frequency's up to 100 Hz. In this way, the cells and their protein products are exposed to rather violent vibratory forces, not unlike those experienced in the human vocal cords during loud voice production. The objective of the research is to determine the underlying molecular causes for voice disorders related to excessive use of the voice.