1. College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, P.R. China
2. National Engineering Laboratory for Clean Technology of Leather Manufacture, Sichuan University, Chengdu 610065, P.R. China
3. College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059, P.R. China
4. Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts 02115, United States