1. Center for Medical Device Evaluation, National Medical Products Administration , Beijing 100081, China
2. State Key Laboratory of Tribology, Tsinghua University , Beijing 100084, China
3. School of Life Science and Technology, China Pharmaceutical University , Nanjing 210009, China
4. National Engineering Research Center for Biomaterials & College of Biomedical Engineering, Sichuan University , Chengdu 610064, China
5. Biotech. & Biomed. Research Institute, Northwest University , Xi'an 710127, China