Fig 1.
The effect of simultaneous SDF-1 and BMP-2 treatment on ectopic bone formation.
Faxitron soft X-ray images after subcutaneous implantation of collagen sponge with/without BMP-2 (2.5μg) and SDF-1 (0, 0.1, 0.5, or 1 μg/collagen sponge) in mice. (A) Radiographic image of the harvested collagen sponges 4 weeks after implantation. (B) Comparison of radiological density of collagen sponges from different treatment groups (*, p < 0.05).
Fig 2.
Histological findings of ectopic bone formation after treatment with various concentrations of SDF-1 with/without BMP-2.
(A) Representative histological sections 4 weeks after surgery (trichrome staining, ×40 in the box). (B) Bone formation ratio (%) and newly formed bone area (mm2) were analyzed histomorphometrically. Concomitant BMP-2 and SDF-1 treatment did not significantly activate ectopic bone formation compared to independent treatment with BMP-2 or SDF-1 alone (*, p < 0.05).
Fig 3.
The effect of simultaneous treatment with SDF-1 and BMP-2 on orthotopic bone formation.
Soft X-ray examination was carried out after implantation of collagen sponges to critical-size calvarial defects with/without BMP-2 (2.5μg) and SDF-1 (0, 0.1, 0.5, or 1 μg/collagen sponge) in mice. (A) Representative radiographic images, (B) Quantification of bone regeneration by radiographic density at 4 weeks post-implantation (*, p < 0.05).
Fig 4.
Histological findings of orthotopic bone formation after treatment with various concentrations of SDF-1 with/without BMP2.
(A) Representative histological sections 4 weeks post-surgery (trichrome staining, ×40 in the box). (B) Bone formation ratio (%) and newly formed bone area (mm2) were analyzed histomorphometrically. Concomitant BMP-2 and SDF-1 treatment did not significantly activate orthotopic bone formation compared to independent treatment with BMP-2 or SDF-1 alone (*, p < 0.05).
Fig 5.
Effect of SDF-1 on ALP activity in C3H10T1/2 mesenchymal cells under osteogenic induction.
SDF-1 did not significantly enhance BMP-2-induced osteoblastic differentiation after 10 days of treatment (*, p < 0.05).
Fig 6.
(A) Representative microscopic images of cells cultured in media containing SDF-1 alone, BMP-2 alone, SDF-1 + BMP-2, or neither factor. (B) Quantification of migration of C3H10T1/2 after 24h treatment with the indicated conditions. Treatment with SDF-1 (0.5μg/ml) and BMP-2 (0.5μg/ml) significantly promoted in vitro cell mobility (*, p < 0.05), while concomitant SDF-1 and BMP-2 application did not further enhance the cell migration.
Fig 7.
Tube formation assay for angiogenesis on Matrigel.
Effect of SDF-1 and BMP-2 on in vitro angiogenesis was evaluated with HUVEC tube formation assay. The tube formation after treatment with SDF-1 alone, BMP-2 alone, combined SDF-1 & BMP-2 were microscopically compared (A). The number of branching point per field (B) and total length of tube per field (C) were quantified by counting 3 random fields/well under the microscope (x4). Representative photos of HUVEC tube formation assay reveal that BMP-2 or SDF-1 alone could significantly activate angiogenesis (*, p < 0.05). However, co-treatment of BMP-2 and SDF-1 did not show additive effect on antigenic tube formation compared to a single treatment of BMP-2.