1. Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University; Beijing 100191 China
2. State Key Laboratory of New Ceramic and Fine Processing, Department of Materials Science and Engineering, Tsinghua University; Beijing 100084 China
3. Department of Biomedical Materials and Engineering; Graduate School of Dental Medicine, Hokkaido University; Sapporo 060-8586 Japan