Ringe, Jochen
Sittinger, Michael
Article History
First Online: 27 May 2014
Competing interests
: M.S. declares that he is a shareholder of BioRetis and CellServe, and that he is a consultant for BioTissue Technologies. He is cofounder of the companies BioRetis, CellServe and TransTissue Technologies. J.R. declares no competing interests.