Figure 4.

The morphologies of the mineralized collagen under different cross-linking conditions. (a) SEM images of the mineralized collagen at 1 mm, 200 μm, and 50 μm scales. A1–A3 are the images of Group A. B1–B3 are the images of Group B. C1–C3 are the images of Group C. D1–D3 are the images of Group D. Hydroxyapatite was found in all four groups. (A3–D3, triangles). (b) A schematic diagram of the mineralization process under different cross-linking conditions. Group A is mineralization after complete cross-linking. Group B is simultaneous cross-linked mineralization. Group C&D is simultaneous cross-linked mineralization after pre-cross-linking. (c) EDS images of mineralized collagen at 1 mm. C stands for carbon, Ca stands for calcium, and P stands for phosphorus. A4–A6 are the images of Group A. B4–B6 are the images of Group B. C4–C6 are the images of Group C. D4–D6 are the images of Group D. (d) A schematic diagram showing that the mineral mass of the dynamic cross-linking group was more deeply embedded in the mineralized collagen, while the mineral mass of the mineralized after cross-linking group was less and was more attached to the surface.