1. State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute at Sichuan University, Chengdu 610065, P. R. China
2. Interdisciplinary Research Centre in Polymer Science & Technology (Polymer IRC), University of Bradford, Bradford BD7 1DP, U.K.
3. Biomedical and Electronics Engineering Department, School of Engineering, University of Bradford, Bradford BD7 1DP, U.K.
4. Advanced Polymer Materials Research Center of Sichuan University, Shishi 362700, P. R. China
5. Chongqing Key Laboratory of Oral Disease and Biomedical Sciences and Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education and Stomatological Hospital, Chongqing Medical University, Chongqing 401174, P. R. China