Fig. 3

In vitro sprouting of endothelial cells into a fibrin hydrogel in response to skin substitute biopsies. a Schematic overview of a 6 mm biopsy (AD, DS, ES or SS) in a transwell above a 3D fibrin hydrogel with a confluent layer of EC on top. b Representative pictures of sprouting assay using human dermal endothelial cells. Pictures show endothelial cells on a fibrin gel exposed to SS or AD biopsy. c Quantification of sprouting in response to AD, DS, ES, SS biopsies after 24–48 h exposure. d Quantification of sprouting in response to AD, DS, ES, SS biopsies after 48–72 h (24 h longer than Fig. 3b so blocking can be observed better). Within an independent experiment, quantification of sprouting occurred at single time point for all variables and was dependent on the sprouting potential of the donor. The exposure is combined with a VEGF or uPAR blocking agent. Significance of stimulation was determined using a Friedman test followed by a Dunn’s multiple comparisons test or a repeated measures one-way ANOVA followed by a Dunnett’s multiple comparisons test. *P < 0.05. Data is shown for 4 donors as mean ± SEM