1. Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO) 1 , Department of Cardiothoracic, Transplantation and Vascular Surgery , , Hannover 30625 , Germany
2. Hannover Medical School 1 , Department of Cardiothoracic, Transplantation and Vascular Surgery , , Hannover 30625 , Germany
3. Centre for Regenerative Medicine, Institute for Regeneration and Repair, School of Biological Sciences, The University of Edinburgh 2 , Edinburgh EH16 4UU , UK
4. Novo Nordisk Foundation Center for Stem Cell Medicine (reNEW), University of Copenhagen 3 , Copenhagen N DK-2200 , Denmark