1. Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
2. Jilin Biomedical Polymers Engineering Laboratory, Changchun 130022, P. R. China
3. Department of Hepatobiliary and Pancreatic Surgery, The First Hospital of Jilin University, Changchun 130021, P. R. China