1. Tissue Engineering & Biofabrication Laboratory, Department of Health Sciences and Technology, ETH Zurich, Otto-Stern-Weg 7, 8093 Zurich, Switzerland
2. Department of Biomedical Engineering, Duke University, 101 Science Dr., Durham, North Carolina 27708, United States
3. Swiss Nanoscience Institute, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland