[Applying an osteoinductive protein complex for regeneration of osseous defects]

Growth factors are still not commercially available for routine clinical use. One possibility might be the application of Colloss, which is supposed to have osteoinductive properties. Therefore, it was the aim of the following animal experimental study to compare Colloss with autogenous bone and to investigate its osteoproductive potential.

In 24 pigs clinically relevant defects were created in the forehead area. Defects were filled with autogenous bone and Colloss. One defect was left unfilled and served as control. After 2, 4, 12 and 26 weeks, six animals were sacrificed and microradiography, light microscopy and immunohistochemistry were carried out using BMP-2 and osteocalcin as antibodies.

After 2 weeks the defects filled with the bovine protein complex showed a mineralization of 52.6% +/-4.03 compared to autogenous bone (38% +/-9.9; p=0.068) and the control defect (30% +/-2.94; p=0.05). After 4 weeks the results became assimilated. Light microscopy revealed especially after 2 weeks an enhanced de novo bone formation in the Colloss-group. This was also evident in an early expression maximum of BMP-2 after 2 weeks. Autogenous bone and the control defect showed a later expression maximum.

Colloss showed an acceleration of bone regeneration in the early phase. Nevertheless, after 26 weeks the results were comparable with the autogenous bone group.