1. Department of Physics, University of California, Santa Barbara, California 93106, USA
2. Department of Surgery, Department of Anatomy, Department of Bioengineering and Therapeutics, and Center for Bioengineering and Tissue Regeneration, University of California, San Francisco, California 94143, USA
3. Department of Orthopaedic Surgery, University of California, San Francisco, California 94143, USA
4. Department of Dentistry, University of Michigan, Ann Arbor, Michigan 48109, USA
5. Department of Biologic and Materials Sciences and Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
6. Department of Materials, University of California, Santa Barbara, California 93106, USA
7. UC Berkeley and UCSF Joint Graduate Group in Bioengineering, Berkeley, California 94720, USA
8. Department of Radiology and Biomedical Imaging, University of California, San Francisco, California 94143, USA
9. Active Life Technologies, 629 State St., Suite 213, Santa Barbara, California 93101, USA
10. Hospital del Mar, Department of Internal Medicine, Autonomous University of Barcelona, P. Maritim 25-29, 08003 Barcelona, Spain