1. Department of Orthopedic Surgery, Washington University School of Medicine, St. Louis, MO, USA
2. Shriners Hospitals for Children, St. Louis, MO, USA
3. Center of Regenerative Medicine, Washington University School of Medicine, St. Louis, MO, USA
4. Department of Mechanical Engineering and Materials Science, Washington University, St. Louis, MO, USA
5. Department of Biomedical Engineering, Washington University, St. Louis, MO, USA