S-1 Supporting Information Enzyme-Sensitive and Amphiphilic PEGylated Dendrimer- Paclitaxel Prodrug-Based Nanoparticles for Enhanced Stability and Anticancer Efficacy Ning Li, †,‡ Hao Cai, † Lei Jiang, ‡,∥ Jiani Hu, § Ashika Bains, § Jesse Hu, § Qiyong Gong, † Kui Luo *,† and Zhongwei Gu *,†,#,∥ † Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital, Sichuan University, Chengdu 610041, China ‡ State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Center of Advanced Pharmaceuticals and Biomaterials, China Pharmaceutical University, Nanjing 210009, China # College of Materials Science and Engineering, Nanjing Tech University, Nanjing 211816, China ∥ National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, China § Department of Radiology, Wayne State University, Detroit, Michigan 48201, United States Corresponding author : Fax: +86 28 85410653; Phone: +86 28 85410336/+86 28 85410653 E-mail: luokui@scu.edu.cn; zwgu1006@hotmail.com