Some broken bones won’t heal.

But now a research team at the Keck School of Medicine at USC is tackling the problem, and one of the lead researchers is the product of Bryn Mawr’s biology department.

Francesca Mariani ’91, a principal 
investigator at USC’s Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, is working with colleagues on ways to repair bone defects too severe to heal. Her partners in the project—the Regenerative Medicine Initiative—are Keck’s Orthopedic Surgery Chair Jay Lieberman and fellow stem cell researcher Gage Crump.

“Each year, about five million people in the U.S. have fractures that fail to heal successfully,” says Mariani. “By using our new bone regeneration model, we can identify the stem cells needed for successful bone healing.”

Working with a seemingly unlikely pair—zebrafish and mice—the team has found repair cells that enable these animals to heal serious injuries. Adult 
zebrafish can repair 20 percent of a missing heart, a severed spinal cord, or up 
to half a jawbone, and mice can likewise heal large-scale injuries to their ribs. 
The Crump and Mariani labs published their findings about zebrafish in the journal Development.

To continue her work with mice, Mariani recently secured a $2.37 million Research Project Grant from the National Institutes of Health. “Going forward,” she says, “we are investigating a promising biological factor that stimulates these cells to mediate repair.”

“The collaboration has really been wonderful for gaining new insights,” says Mariani. By bringing together researchers and clinicians, the initiative focuses on areas that may be of most clinical use for patients. Among those who may benefit? People with large bone defects associated with revision total hip and knee replacement and soldiers who have lost soft tissue and bone from gunshot or IED wounds.

Francesca Mariani, '91
Francesca Mariani '91
Investigator at USC’s Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research

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