1. Department of Rheumatology and Clinical ImmunologyCharité‐Universitätsmedizin Berlin, Tissue Engineering Laboratory and Berlin‐Brandenburg Center for Regenerative TherapiesCharitéplatz 1 10117 Berlin Germany
2. Julius Wolff Institute and Berlin‐Brandenburg Center for Regenerative TherapiesCharité‐Universitätsmedizin BerlinFöhrer Straße 15 13353 Berlin Germany