1. Max-Planck-Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
2. Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, P.R. China
3. Department of Dermatology, University Medical Center Mainz, Johannes Gutenberg-University Mainz, Mainz D-55099, Germany