Tissue Engineering: The Organ Builder
Joseph Vacanti has already engineered skin and bone, but what he really hopes is to grow whole, functional organs.
Denise Bosco for Proto
Joseph P. Vacanti, surgeon-in-chief at MassGeneral Hospital for Children, is widely considered a pioneer in the field of tissue engineering. Already having developed applications ranging from rebuilding the deformed sternum of a 12-year-old boy to using cells and sea coral to give a man a new thumb, he continues in pursuit of his holy grail: three-dimensional, fully functional organs.
Q: What is tissue engineering?
A: It’s the process of building tissue using a combination of living cells and nonliving materials—for example, encouraging cells to grow outside the body on scaffolds made of biodegradable polymers.
Q: What are the potential uses?
A: There are many—for instance, skin replacement patches to help heal persistent wounds or ulcers. Corneas, bladders and bronchial tubes are now being tested in clinical trials. Ultimately, though, the goal is to create entire organs that could eliminate the need for donors. And because organs could be customized from a recipient’s own cells, there would be no chance of rejection.
Q: What’s the actual construction process like?
A: Nanotechnology enables us to create silicon templates etched with networks of vessels. We make a cast from polymer. Then the tiny grooves in the polymer are seeded with endothelial cells, the cells that form blood vessels in the body. Within a few days, the cells grow and form capillary-like tubes.
Q: When might whole organs be ready for testing in humans?
A: I ask myself that question every day. More likely in the near term are mechanical devices that can be implanted to help a diseased organ function better. We’re working right now on an implantable lung-assist device that has a vascular structure. For a person suffocating from lung disease, the device could help the lung exchange oxygen and carbon dioxide in the blood. Depending on funding, we could be ready for animal trials within two years.