* Corresponding authors

^a College of Chemical Engineering, Fuzhou University, Fuzhou 350116, P. R. China
E-mail: jyhuang@fzu.edu.cn, yklai@fzu.edu.cn

^b National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou 215123, P. R. China

^c Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California 90095, USA

^d Department of Biomedical Sciences, City University of Hong Kong, Hong Kong 999077, P. R. China

^e School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore, Singapore