1. Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
2. Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
3. Department of Biochemistry and Molecular Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
4. Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota 55902, United States