Fig. 2

Fig. 2

Three-dimensional assays of vascular morphogenesis. a A fibrin bead assay uses collagen I- and EC-coated Cytodex beads embedded within a 3D fibrin gel matrix to measure EC sprouting and lumen formation. b These features are readily resolved using phase-contrast microscopy. c EC tube formation can be measured by embedding EC within a collagen I matrix. d Once formed, these tubes can be visualized by toluidine blue staining and bright-field microscopy. e Whole-mount, dissected retinas from postnatal mice are mounted within collagen I-Matrigel matrix mix and cultured in pro-angiogenic medium to stimulate EC sprouting. f Sprout and lumen formation are resolved using phase-contrast microscopy. g The vascularized micro-organ (VMO) approach utilizes “arteriole” (high pressure) and “venule” (low pressure) microfluidic channels to drive medium diffusion and flow across a cell chamber where microvasculature forms. h The formed microvasculature (EC, red) can be measured for leak by perfusion with 70 kDa FITC-dextran (green)