1. Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
2. Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, IN 46556, USA.
3. Department of Mechanical Engineering, Trinity Center for Bioengineering, Trinity College Dublin, Dublin D02 PN40, Ireland.
4. Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA.
5. Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
6. Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA.
7. Department of Orthopaedic Surgery, Case Western Reserve University, Cleveland, OH 44106, USA.
8. National Center for Regenerative Medicine, Division of General Medical Sciences, Case Western Reserve University, Cleveland, OH 44106, USA.