1. Key Laboratory of Polymeric Materials and Application Technology of Hunan Province, College of Chemistry, Xiangtan University, Xiangtan, Hunan 411105, China
2. Department of Orthopedics, the Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
3. State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083, China