1. School of New Energy and Materials, Southwest Petroleum University, Chengdu 610500, P. R. China
2. Department of Nuclear Medicine & Laboratary of Clinical Nuclear Medicine, West China Hospital of Sichuan University, Chengdu 610041, P. R. China
3. National Engineering Research Center for Tissue Restoration and Reconstruction, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510006, P. R. China
4. Institute of Metallic Biomaterials, Helmholtz-Zentrum Hereon GmbH, 21502 Geesthacht, Germany