1. Department of Microbiology and Immunology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
2. State Key Laboratories for Agro-biotechnology and College of Biological Sciences, China Agricultural University, Beijing 100193, China
3. Laboratory of Nanomedicine and Nanosafety, Division of Nanomedicine and Nanobiology, National Center for Nanoscience and Technology, Beijing 100190, China
4. CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Chinese Academy of Sciences, Beijing 100190, China
5. Laboratory of Molecular Imaging, Department of Radiology, Howard University, Washington, DC 20060, USA