1. Key Laboratory of Polymer Ecomaterials; Changchun Institute of Applied Chemistry; Chinese Academy of Sciences; Changchun 130022 P. R. China
2. School of Materials Science and Engineering; Sun Yat-Sen University; Guangzhou 510275 P. R. China
3. Department of Orthopaedics; The Second Hospital of Jilin University; Changchun 130041 P. R. China