1. Center for Biomaterials, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
2. Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
3. Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea
4. Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford OX37LD, U.K.
5. Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Republic of Korea