1. School of Basic Medicine, State Key Laboratory of Bio-Fibers and Eco-Textiles & College of Textiles and Clothes, Qingdao University, No. 308 Ningxia Road, Qingdao 266071, P. R. China
2. Department of Molecular Science and Nanosystems, Ca' Foscari University of Venice, Via Torino 155, 30172 Venezia Mestre, Italy
3. Division of Materials Science, Department of Engineering Sciences and Mathematics, Luleå University of Technology, 971 87 Luleå, Sweden