To develop the fracture putty material, the Department of Defense awarded grants to three research teams. Two of those teams are headquartered in Houston – one at The University of Texas Health Science Center, and the other at Baylor College of
Medicine.

Mauro Ferrari, director of UT-Houston’s Division of Nanomedicine, heads the UT team. Ferrari was awarded $5.2 million in initial funding to develop a putty to treat non-union fractures – fractures that generally will not heal in a timely manner and can lead to amputations. Total funding to UT, if all phases of the development program are completed, could increase to $7.9 million over two years. The UT-team is multi-institutional, and includes partners from Baylor and Rice as well as Harvard, Northwestern and Texas A&M Universities.

Baylor was awarded a two-year, $4.5 million contract to use an alternative approach to develop the fracture putty. Baylor’s multi-institutional team is led by Michael Heggeness, M.D., chair of the college’s orthopedics department. Jennifer West, Ph.D., chair of bioengineering at Rice University, is co-principal investigator of the Baylor study. Other researchers on the Baylor team are from UT-Houston and the University of Georgia.

Serious leg injuries typically are repaired with bone grafts. Pins, plates or screws hold the grafts to healthy bone and external fixators provide support. Patients may require multiple surgeries and recuperation periods of about a year. And, they may not recoup full use of the injured leg.

If fracture putty proves successful, injured patients could fundamentally regain full use of their legs in a much shorter period of time, Ferrari said.

"Success on even a small part of the project has the potential to revolutionize orthopedic medicine. It could give people with serious leg injuries an opportunity to regain full use of limbs that now require amputations or the use of permanent implants," Ferrari said. "We’re creating a living material that can be applied to crushed bones. The putty will solidify inside the body and provide support while the new bone grows."

Heggeness said Baylor is developing a treatment that would be implemented quickly and efficiently after an injury involving seriously fractured bones.

"Our hope is to create a process that would put a stop to the many amputations that too often follow such injuries," he said.

"Anything you can do to start the healing process as quickly as possible is good for the patient," said John Holcomb, M.D., a retired U.S. Army surgeon who now heads the Center for Translational Injury Research at the UT-Houston. "This could reduce the risk of infection and the onset of complications."

Ennio Tasciotti, Ph.D., a research assistant professor in Ferrari’s lab, said the putty being developed at UT-Houston will include a material called nanoporous silicon that was developed in Ferrari’s lab, which will give the putty the strength it needs to support the patient’s weight while new bone tissue is being regenerated.

Other materials will be used in the putty as well, and will require the contributions of a team of the best scientists in the fields of nanoporous silicon, bio-mimetic peptides, bio-polymers, stem cells and adhesives, Tasciotto said.

The final formula, he said, "will come from the integration of nanomaterials with unique properties in a smart composite substance that can mimic bone structure and function."

The fracture putty will serve as a bioactive scaffold and will be able to substitute for the damaged bone, Tasciotti explained.

"At the same time, the putty will facilitate the formation of natural bone and self-healing in the surrounding soft tissue through the attraction of the patient’s own stem cells," he said. "The putty will have the texture of modeling clay so that it can be molded in any shape in order to be used in many different surgical applications including the reconnection of separated bones and the replacement of missing bones."

Tasciotti said the fracture putty could one day be used to address injuries involving the spine, skull and facial bones.

robert.cahill@uth.tmc.edu
pathak@bcm.edu