1. Department of Pharmaceutics and Bioengineering, School of Chemical Engineering, Sichuan University, Chengdu 610065, P. R. China
2. College of Chemistry and Environment Protection Engineering, Southwest Minzu University, Chengdu 610041, P. R. China
3. Key Laboratory of Leather Chemistry and Engineering (Sichuan University), Ministry of Education, Chengdu 610065, P. R. China