Modulation of angiogenic sprouts by growth factors. (A) Representative micrographs of hARs treated with basal medium (EBM-2), basal medium plus VEGF-A (10 ng/mL), or complete medium (EGM-2) for 15 days. Scale bar represents 200 μm. (B) The left panel shows representative output data of computer-assisted image analysis, as shown in supplemental Figure 3A. The right panel shows quantification of the angiogenic outgrowth at 15 days of hAR culture. 5% FCS EBM-2 plus heparin (basal medium) with the addition of indicated concentrations of specific GFs or complete EGM-2 (complete medium). Values shown are box-and-whisker plots, normalized to the median of complete medium hARs, of 3 independent experiments, each from 6 different umbilical cords (*P < .05 vs basal medium hARs; **P < .01). (C) Time course of angiogenic outgrowth lengths (normalized to day 16) and velocity (normalized to day 14) of hARs cultured with complete medium (EGM-2). Values shown are mean ± SD of 3 independent experiments, each from 6 different umbilical cords. Graphs represent the computer-assisted quantification shown in supplemental Figure 2A.