“Tissue engineering doesn’t have a great history of making a clinical impact,” says Elisseeff. “So there’s a strong need to show we can do that and improve patient care.” As for when that last step will take place, Elisseeff estimates that technologies spawned from the center’s labs will begin to be introduced into clinical practice within the next five years to 10 years. Some, she says, are already in clinical testing.
Cornea transplantation is the most common transplant procedure. In the United States alone, surgeons perform 40,000 of the operations each year. Corneal tissue, however, is in tight supply in this country, and worldwide there is a dire shortage. But what if medical labs could manufacture artificial corneas from components that are easier to come by?
Another center scientist, assistant professor of biomedical engineering Warren Grayson, is focusing on a different type of tissue—bone. To build his constructs, Grayson begins with spongy bone from the cow knee joint. Through chemical processes, he removes all cells from the bone until only a mineral scaffold remains. Using a milling tool, he sculpts this material into the size and shape of the segment to be transplanted, and then he infuses the scaffolding with stem cells and places this material in a special compartment called a bioreactor that provides an environment conducive to the growth of stem cells. During the course of several weeks, the cells grow to fill in the scaffolding with bone tissue.
Yet another scientist at the center, Hai-Quan Mao, associate professor of materials science and engineering and biomedical engineering, is developing biomaterials and methods to regenerate and repair nerve tissue. Normally, nerve cells are surrounded by a scaffolding of proteins and sugar residues, which help regulate the growth of those cells. So Mao is attempting to replicate this extracellular microenvironment using biodegradable polymers. Through a method called electrospinning, he forms the polymer into minute fibers of diameters less than a micron. He then seeds neural stem cells onto the fibers.