1. School of Materials Science and Engineering; Nanyang Technological University; N4.1, Nanyang Avenue Singapore 639798 Singapore
2. School of Biological Sciences; Nanyang Technological University; 60 Nanyang Drive Singapore 637551 Singapore
3. Department of Pharmaceutics; Indian Institute of Technology (BHU); Varanasi 221005 India
4. Department of Chemical and Biomolecular Engineering; National University of Singapore; 4 Engineering Drive 4 Singapore 117585 Singapore
5. International Joint Cancer Institute; The Second Military Medical University; 800 Xiang Yin Road Shanghai 200433 P.R. China