Fig. 5

Angiogenesis promoted by mechanical strain in microfluidic devices even without stromal cells. a Representative images of multi-chambered microtissue devices with HUVECs and NHLFs in the center chamber with CAFs or NBFs in the side chambers. Devices were grown for 8 days, with treatments being added after 4 days. Devices were stained for VE-Cadherin (red). White arrows identify vessel structures. Dashed lines show interfaces between chambers. Scale bar = 500 µm. b Quantification of vessel growth in the side chambers using AngioTool and FIJI, shown as total length in side chamber normalized to total length in center chamber for each microtissue model. * p < 0.05 versus Vehicle-treated NBF. c Representative images of multi-chamber microtissue devices with HUVECs and NHLFs in the center chamber and either blank (cell- and bead-free) fibrin only or fibrin gels plus magnetic microbeads in the side chambers. Samples received either no magnetic stimulation (No Magnet) or were cultured above a rotating magnetic field (Magnet). Systems were stained for VE-Cadherin (red) after 7 days of culture time. White arrows identify vessel structures. Dashed lines show interfaces between chambers. Scale bar = 500 µm. d Quantified results of vessel growth in side chambers; vessel in side chambers was first normalized to explant or gel area for the chamber, then all values were normalized to the total length/explant area of the side chamber. * p < 0.05 versus No Magnet. For a, b, n ≥ 7 devices per condition. For c, d, n = 4 for Blank + No Magnet, n = 5 for Blank + Magnet, and n ≥ 7 for both Beads groups. Data shown as average + SEM, n ≥ 3 samples. Group b was compared with Kruskal–Wallis test, followed by post hoc Dunn’s tests. Group d was compared with ANOVA, followed by post hoc Tukey HSD tests