1. McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.
2. Department of Orthopedic Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
3. Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, Pennsylvania.
4. Department of Cell Biology, Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, Pennsylvania.
5. Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania.