1. Disease Biophysics Group, John A. Paulson School of Engineering and Applied Sciences, Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts 02452, United States
2. Center for Nanotechnology and Nanotoxicology, Harvard T.H. Chan School of Public Health, Harvard University, Cambridge, Massachusetts 02138, United States
3. Department of Materials Science & Engineering and Particle Engineering Research Center, University of Florida, P.O. Box 116135, Gainesville, Florida 32611, United States