1. Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
2. Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
3. Division of Gastroenterology and Hepatology, Department of Medicine and Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, United States
4. Institute for NanoBiotechnology, Johns Hopkins University, Baltimore, Maryland 21218, United States