1. College of Material Science & Engineering, Beijing University of Chemical Technology, Beijing, P.R. China.
2. Beijing Laboratory of Biomedical Materials, State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, P.R. China.
3. National Center for Orthopaedics, Institute of Traumatology and Orthopaedics, Beijing Jishuitan Hospital, Beijing, P.R. China.
4. National Center for Orthopaedics, Beijing Jishuitan Hospital, Institute of Traumatology and Orthopaedics, Beijing, P.R. China.