1. Department of Orthopaedic Surgery, National University of Singapore, Singapore 119074, Singapore
2. State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, P.R. China
3. Department of Mechanical Engineering, National University of Singapore, Singapore 117576, Singapore
4. College of Materials Science and Engineering, Hunan University, Changsha 410082, P.R. China