Imagine if weak or injured bones could be repaired simply by injecting a patient with a soft material that, once inside the body, would bond to existing bone at the molecular level, matching its hardness and strength. Researchers from Uppsala, Sweden-based Doxa have recently started human tests of just such a patching material. Today's artificial-bone materials, usually made from calcium phosphate or polymers, either have serious side effects or are not strong enough to replace bone in certain areas, such as the spine. Doxa's material, however, reacts to body fluids to form apatite, the body's own ceramic, to make artificial bones just as strong as the original. If the material proves to be as good as inventor Leif Hermansson, a materials scientist at Uppsala University, claims, it could bring relief to millions of patients. In the United States alone, an estimated 10 million people suffer from osteoporosis-one of the first disease targets for which Doxa hopes to get the material approved, perhaps within the year.