1. School of Materials Science and Engineering Nanyang Technological University Singapore 639798 Singapore
2. Center for Nanotechnology and Nanotoxicology Harvard T.H. Chan School of Public Health Harvard University 665 Huntington Avenue Boston MA 02115 USA
3. Environmental Chemistry and Materials Centre Nanyang Environment and Water Research Institution Nanyang Technological University 1 Cleantech Loop, CleanTech One Singapore 637141 Singapore
4. Skin Research Institute of Singapore Biomedical Science Institutes Immunos, 8A Biomedical Grove Singapore 138648 Singapore