1. Laboratory of Nanomedicine and Nanosafety, Division of Nanomedicine and Nanobiology, National Center for Nanoscience and Technology, China, and CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Chinese Academy of Sciences, Beijing 100190, China
2. Department of Chemistry & Chemical Engineering, College of Environment and Energy Engineering, Beijing University of Technology, Beijing 100124, China
3. Molecular Imaging Laboratory, Department of Radiology, Howard University, Washington, D.C. 20060, United States
4. Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, Maryland 20740, United States