Dental scientists are pushing tissue engineering technology to new levels, investigating a combination of therapies to more efficiently regenerate facial skin and bone, according to a University of Michigan dental scientist.
Tissue engineering typically involves harvesting a small sample of cells, treating them in the lab, and then reintroducing the cells into a damaged area, such as a jawbone damaged so severely from disease or trauma that it cannot heal on its own. A tiny, biodegradable scaffold or template helps direct the engineered cells to the right place, dissolving once the cells begin to generate to fill in the wound.
However, there are obstacles in craniofacial regeneration for some patients, according to Paul H. Krebsbach, DDS, PhD, associate professor, University of Michigan's School of Dentistry and chair of its Department of Biologic and Material Sciences.
"Regenerating the jawbone of a person undergoing radiation therapy for cancer, means managing the constant bombardment of mouth bacteria and damage from radiation," he says. "Gene therapy may overcome the damaging effects of radiation, but we foresee the potential of obtaining maximal results through a combination of therapies."
Potential of unrelated therapies
He told attendees today at the American Dental Association's national media conference that he and fellow researchers are focusing on the potential of combining unrelated therapies to help overcome such obstacles, improving the benefits of tissue engineering.
For example, he says, parathyroid hormone (PTH), which is naturally produced by the parathyroid gland, can stimulate bone growth and regulate the amount of calcium and phosphorus in the body. Giving patients with osteoporosis injections of extra PTH can help induce bone growth.
"PTH's anabolic or bone-stimulating properties," Dr. Krebsbach says, "provides another therapy that has strong potential for similar gains in tissue-engineering new bone growth."
By pairing injections of PTH with gene therapy for bone morphogenetic proteins (BMPs), which are proteins that can naturally exist in cells and induce bone formation, he explains, we can encourage cells to differentiate specific kinds of bone during tissue engineering.
"Together, these therapies have the potential to be more effective than single therapies for bone regeneration and to overcome compromised environments," he says.
If the combination therapy approach works, Dr. Krebsbach says the next step would be working with engineers to develop anatomically correct scaffolding with the same curvature and contours of natural bones. That would help a patient develop new bone almost indistinguishable from nature's original equipment.