1. Department of Nanoengineering, University of California San Diego, La Jolla, California 92093, United States
2. Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Allston, Massachusetts 02134, United States
3. Sansum Diabetes Research Institute, Santa Barbara, California 93105, United States
4. Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts 02215, United States