Figure 7. Histological analysis of new bone formation at 12 weeks post-surgery.

Van Gieson staining showed more bone formed in tubular scaffolds (Group C) than porous (Group A and B) and solid (Group D) ones, especially in the center of grafts (blue arrow). The center region of porous scaffold was occupied by soft tissue with poor osteogenesis (red arrow). The tissue stained in red color was the newly formed bone with visible cell nuclei. The tissue stained in yellow/green/blue color was fibrous tissue. Scale bar: 1 mm (white), 100 µm (blue).