1. BioInterface Group, Helmholtz Institute for Biomedical Engineering, RWTH Aachen University, Pauwelsstrasse 20, 52074 Aachen, Germany
2. Institute of Pathology, RWTH Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany
3. Functional and Interactive Polymers, Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
4. DWI–Leibniz Institute for Interactive Materials, RWTH Aachen University, Forckenbeckstraße 50, 52074 Aachen, Germany
5. Electron Microscopic Facility, University Clinics, RWTH Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany