1. Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing 100871, P. R. China
2. Laboratory of Tissue Regeneration and Immunology and Department of Periodontics, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, School of Stomatology, Capital Medical University, Beijing 100050, P. R. China
3. Department of Oral and Maxillofacial Surgery, The First Clinical Division, The Third Clinical Division, and The Fifth Clinical Division, Peking University School of Stomatology, 100020 Beijing, P. R. China
4. Key Laboratory of Science and Technology on High-tech Polymer Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
5. Department of Orthopedics, Peking University Third Hospital, Beijing 100191, P. R. China
6. Department of Orthopaedic Surgery, Peking University First Hospital, Beijing 100034, P. R. China
7. Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing 100871, P. R. China