Figure 10.
Anti-integrin antibody coated beads induce angiogenesis in the absence of collagen. Endothelial cells were exposed to 0.5 × 107 beads/cm2 polystyrene beads (3 μm diameter) coated with bovine serum albumin as a negative control (A,B), anti-α2β1 integrin antibodies (C,D), and collagen (E,F). At 24 h, monolayers were rinsed and photographed. BSA beads showed no activity (A) and interacted with cells poorly (B). Anti-α2β1 integrin antibody-coated beads induced tube formation similar to that of an apical collagen gel ((C), see Figure 9) and interacted extensively with cells (D). Collagen-coated beads induced angiogenesis (E) and also interacted extensively with cells (F). Top row: Bar = 100 μm. Bottom row: 20× objective. Bead diameters = 3 μm. Reprinted with permission from [106].