1. BRICS Joint Laboratory on Biomedical Materials, School of Materials and Energy, Southwest University, Chongqing 400715, P. R. China
2. College of Sericulture, Textile and Biomass Sciences, Southwest University, Chongqing 400715, P. R. China
3. Department of Chemical and Biomolecular Engineering, National University of Singapore, Kent Ridge, Singapore 117576, Singapore