Biomedical engineers at The University of Texas Health Science Center at Houston are leading a multi-institution initiative to produce a bio-compatible compound designed to mend serious leg fractures.
Explosions can shatter bones into what is called a non-union fracture. The bones generally will not heal in a timely manner. It can lead to amputation.
If fracture putty proves successful, injured soldiers could fundamentally regain full use of their legs in a much shorter period of time. It could also be used in emergency rooms to treat civilians injured in traffic accidents and other traumatic events.
In separate but related work, The university of Montreal has modified metal surfaces for better medical implants and for better acceptance in the body of metal prostheses
Back to the Darpa, University of Texas work on fracture putty:
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.”
DARPA Program Manager Mitchell Zakin, Ph.D., said: “This undertaking represents the ultimate convergence of materials science, mechanics and orthopedics. I look forward to the first results, which should present themselves in about a year or so.”
Ferrari’s team will begin the pre-clinical study by testing the mechanical and biological properties of candidate compounds in mathematical models and in vitro systems. Afterward, the compounds will be tested in several animal models. The study, BioNanoScaffolds for Post-Traumatic OsteoRegeneration,” runs through December 2010.
Ennio Tasciotti, Ph.D., a research assistant professor in Ferrari’s lab, said the putty 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.
Developing a new way to repair long bone injuries is extremely challenging. According to Tasciotti, “This problem 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. The solution will come from the integration of nanomaterials with unique properties in a smart composite substance that can mimic bone structure and function.”
He added, “The fracture putty will serve as a bioactive scaffold and will be able to substitute for the damaged bone. 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. 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.
Osteomyelitis is (OM) a bone infection caused by various bacteria, and usually occurs in severe fractures when bone is exposed to open air. Current antibiotics often kill a strain of bacteria responsible for a disease, only to create a vacuum quickly filled by related strains. The widespread overprescribing of antibiotics and the speed of bacterial evolution have greatly increased the likelihood that the strains most able to resist antibiotics will thrive. Multi-drug resistant (MDR) bacterial strains are now widespread in all hospitals. While bone cements laced antibiotics against staph and strep infections are common (e.g. vancomycin), no group had ever developed a bone cement treatment using colistin against A. baumannii.
To begin the process of providing such a treatment for soldiers, a team of orthopaedic, military and pharmaceutical researchers came together to conduct the current study, the results of which argue for a human clinical trial with colistin-laced bone cement, University of Rochester Medical Center researchers said.