1. Department of Chemistry, Paderborn University, Warburger Str. 100, D-33098 Paderborn, Germany
2. School of Polymer Science and Engineering, Qingdao University of Science and Technology, Zhengzhou Rd. 53, CN-266042 Qingdao, China
3. Institute of Pharmaceutical Technology and Biopharmacy, University of Münster, Corrensstr. 48, D-48149 Münster, Germany