1. Departments
of Biomedical Engineering, Chemistry, and Medicine, Boston University, 590
Commonwealth Ave., Boston, Massachusetts 02215, United States
2. Center
for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center and Harvard Medical School, 1 Overland Street, RN 115, Boston, Massachusetts 02215, United States
3. Ionic Pharmaceuticals, Boston, Massachusetts 02445, United States
4. Department
of Radiology, Boston University School of Medicine, Boston, Massachusetts 02118, United States