1. Departments of Surgery and Bioengineering, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania - USA
2. Charité, Campus Virchow, AG Experimental Surgery, University Medicine Berlin, Berlin - Germany
3. Burn Center, Department for Plastic Surgery, Unfallkrankenhaus Trauma Hospital Berlin, Berlin - Germany
4. StemCell Systems GmbH, Berlin - Germany