1. Department of Otorhinolaryngology, Ulm University Medical Center, Ulm, Germany.
2. Institute of Bioprocess Engineering, University of Erlangen, Erlangen, Germany.
3. Institute of Orthopaedic Research and Biomechanics, Centre of Musculoskeletal Research Ulm, University of Ulm, Ulm, Germany.
4. Central Electron Microscopy Facility, University of Ulm, Ulm, Germany.