1. Department of Orthopaedic Surgery, Stanford University, Stanford, California, USA.
2. Department of Orthopaedic Surgery, Kyoto University, Kyoto, Japan.
3. Department of Mechanical Engineering, Stanford University, Stanford, California, USA.
4. Department of Chemistry, Stanford University, Stanford, California, USA.
5. Department of Materials Science and Engineering, Stanford University, Stanford, California, USA.
6. Department of Bioengineering, Stanford University, Stanford, California, USA.