Bone repair investigation using rhBMP-2 and angiogenic protein extracted from latex.

BACKGROUND

The aim of this work was to study the new bone tissue formation after bone morphogenetic protein type 2 (rhBMP-2) and P-1 application, using 5 and 10 μg of each, combined to a material carrier, in critical bone defects.

METHODS

It was used 70 Wistar rats (male, ∼250 g) that were divided in 10 groups with seven animals on each. Groups are the following: critical bone defect only, pure monoolein gel, 5 μg of pure P-1, 5 μg of pure rhBMP-2, 5 μg of P-1/monoolein gel, 5 μg of rhBMP-2/monoolein gel, 10 μg of pure P-1, 10 μg of pure rhBMP-2, 10 μg of P-1/monoolein gel, 10 μg of rhBMP-2/monoolein gel. Animals were sacrificed after 4 weeks of the surgical procedure and the bone samples were submitted to histological, histomorphometrical, and immunohistochemical evaluations.

RESULTS

Animals treated with pure P-1 protein, in both situations with 5 μg and 10 μg, had no significant difference (P > 0.05) for new bone formation; other groups treated with 10 μg were statistically significant (P < 0.05) among themselves and when compared with groups in which it was inserted the monoolein gel or critical bone defect only (P < 0.05). In the group involving the 10 μg rhBMP-2/monoolein gel association, it was observed an extensive bone formation, even when compared with the same treatment without the gel carrier.

CONCLUSION

Using this experimental animal model, more new bone tissue was found when it was inserted the rhBMP-2, especially when this protein was combined to the vehicle, and this process seems to be dose dependent.