The Effect of Bone Morphogenetic Protein-2 on the Irradiated Allogenic Cartilage of Rats

Abstract

Autogenous cartilage graft is associated with the problem of chondrocyte dedifferentiation. Bone morphogenetic protein-2 (BMP-2) plays an important role in the differentiation and matrix maturation of chondrocytes, and preventing their dedifferentiation. This study was performed on 48 rats, divided equally into 3 groups. In group I, the xiphoid process cartilage was harvested and irradiated, and broken into 2 pieces. Each piece was implanted on the back. The same process was performed in Groups II and III, but further treated with BMP-2, Group II with 25 mu g, and Group III with 50 mu g. The implanted cartilage pieces were reharvested at postoperative weeks 2 and 4. The weight change was measured and histological evaluation was performed. The extent of the weight change was higher in Groups II and III than in Group I. The extracellular matrix between the chondrocytes showed increased in Groups II and III. The fibrous tissue on the surface of the cartilage increased in Groups II and III. Ossification of the chondrocytes was observed in Groups II and III. The use of BMP-2 increased the matrix between chondrocytes and the fibrous tissue of the cartilage and facilitated the ossification of chondrocytes. The effect of BMP-2 increased with its increasing concentration, and maintenance of its effectiveness over time was confirmed.