Additional file 2 of Process data of allogeneic ex vivo-expanded ABCB5+ mesenchymal stromal cells for human use: off-the-shelf GMP-manufactured donor-independent ATMP

Additional file 2 : Fig. S1. Photographic documentation of the cell monolayer at 70% confluency. Original total magnification × 200. Fig. S2. Tube formation assay on extracellular matrix gel. ABCB5+ mesenchymal stem cells (1 × 105 and 1.5 × 105) were seeded in two wells of a Geltrex™-coated 24-well plate and incubated for 19–22 h. Tube formation was evaluated visually according to the following categories: A tubular branches of several cells forming a defined network-like structure; B tubular branches of several cells clustering together forming broad strands, formation of syncytia, areas of high cellular density lacking formation of tubular branches; C cells clustering together, building nodes and forming tubular branches that connect the nodes with each other; D only sporadic cells form tubular branches, partial node formation, but no or nearly no connections between nodes, no or only sporadic apoptotic cells; E largely apoptotic cells, no or only sporadic tubular branches; F no tubular branches. Human umbilical vein endothelial cells (HUVEC) and human skin melanoma cells (SK-MEL-28) served as positive and negative controls, respectively. Categories A–C are considered as successful angiogenic differentiation. Original total magnification × 40.