Vitronectin coating of anorganic bone enables podosome belt formation and resorption.

<p>Osteoclasts were incubated for 5 hours in MEM/BSA with M-CSF (50 ng/ml), RANKL (30 ng/ml) and IL-1α (10 ng/ml) on slices of anorganic bone coated with vitronectin or fibronectin (50 µg/ml). Podosome belts and excavations were frequently seen on vitronectin-coated anorganic bone slices (A, C), but were never seen on fibronectin-coated anorganic bone slices (B, D). A, B: Phalloidin/DAPI staining; C, D: SEM images. Scale bars A–C: 25 µm; D: 50 µm.