Figure 3.

Representative scanning electron microscope images of collagen matrices with mineral gradients at different locations along the matrix lengths. The SBF-mineralized scaffolds (two rightmost columns) show an increasing number of mineral deposits on the surfaces with increasing incubation time (e.g. 0 versus 12 mm). Higher magnification shows that the mineral crystals are plate-like and display rosette configurations. There was an absence of mineral on the surfaces of the SBF + Fet samples. The surfaces of these matrices were covered with a morphologically amorphous material (presumably fetuin protein). The unmineralized collagen matrices (left column) appear porous and composed of randomly oriented fibrils. SBF column scale bars = 10 µm. All other scale bars = 2 µm.