1. Key Laboratory for Ultrafine Materials of Ministry of Education, and Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237, People's Republic of China
2. Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Inter-disciplinary Studies, Peking University, Beijing 100871, People's Republic of China
3. Department of Biomedical Engineering, Inje University, First Research Group/BK-21, Gimhae 621-749, Republic of Korea