1. Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States of America
2. Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States of America
3. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States of America
4. Nanotechnology Characterization Laboratory, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States of America
5. Laboratory of Animal Sciences Program, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States of America
6. Molecular Histology and Pathology Laboratory, Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States of America