

When bombs shatter bones with compound fractures, it can take multiple surgeries and lots of rehab to set things right. So Darpa, the Pentagon's premiere research shop, wants to "develop a dynamic putty-like material" that can be packed around a shattered bone, support the body while the patient heals – and bio-degrade, once it's all over.

If successful, this "Fracture Putty" could "rapidly restore a patient to ambulatory function while normal healing ensues, with dramatically reduced rehabilitation time and the elimination of infection and secondary fractures," the agency notes.

But, like all Darpa programs, it'll be tough. Challenges for the program include:

*...novel bioresorbable adhesives which bond preferentially to bone vs. soft tissues, with bone-like mechanical properties, in the wet biological environment; load-bearing biomaterials with high mechanical strength and high porosity that match the mechanical properties of bone; biomaterials which create hierarchical bone-like internal structure; and biomaterials which adapt to biochemical cues. *

There's a meeting on July 1 in Virginia, to kick off the program.