1. Department of Chemistry, International Institute for Nanotechnology, Simpson-Querrey Institute, Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, United States
2. Shu Chien-Gene Lay Department of Bioengineering and the Sanford Consortium for Regenerative Medicine, University of California San Diego, La Jolla, California 92037, United States
3. Medical Scientist Training Program, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, United States
4. Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, United States
5. Department of Materials Science & Engineering, Department of Pharmacology, Northwestern University, Evanston, Illinois 60208, United States
6. Department of Chemistry & Biochemistry, University of California San Diego, La Jolla, California 92037, United States