1. Department of Biomedical Engineering, University of Delaware, Newark, Delaware, USA.
2. Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, USA.
3. Department of Physical Therapy, University of Delaware, Newark, Delaware, USA.
4. Department of Materials Science and Engineering, University of Delaware, Newark, Delaware, USA.
5. Department of Orthopaedic Surgery, University of Michigan Medical School, Ann Arbor, Michigan, USA.