1. Department of Trauma, Hand and Reconstructive Surgery University Hospital Essen Essen Germany
2. Central Animal Laboratory University Hospital Essen Essen Germany
3. Clinic and Policlinic for Dermatology and Venereology University Medical Center Rostock Rostock Germany
4. Department of Materials Science and Engineering University of Duisburg‐Essen Germany
5. Department of Plastic Surgery, BG University Hospital Bergmannsheil Ruhr University Bochum Bochum Germany
6. Universitätsklinikum Essen