Effect on Bone Induction of Using Contrast Media to Reconstitute Recombinant Human Bone Morphogenetic Protein-2 in an Ectopic Model in Rats

Document Type

Article

Language

eng

Publication Date

11-2006

Publisher

American Association of Neurological Surgeons

Source Publication

Journal of Neurosurgery: Spine

Source ISSN

1547-5654

Abstract

Object

In this study the authors tested the osteoinductive potential of recombinant human bone morphogenetic protein–2 (rhBMP-2) when combined with each of three commercially available contrast media (Conray, Omniscan, and Optiray).

Methods

Initial in vitro and cadaver tests verified the feasibility of using contrast media to visualize absorbable collagen sponge implants containing rhBMP-2 on fluoroscopic radiographic images. For the feasibility studies, lyophilized rhBMP-2 was prepared for injection by reconstitution with contrast media instead of sterile water. For the in vivo study, samples of an rhBMP-2 stock solution were diluted to 0.1 mg/ml by using three contrast media. In each sample, the final solution consisted of 97% contrast medium by volume. Recombinant human bone morphogenetic protein–2 diluted with sterile water for injection was used as a positive control. The rhBMP-2 solutions were applied to 0.5-cm3 collagen sponges and implanted subcutaneously on the thoracic cavity of athymic rats. At 4 weeks, the rats were killed, and the implants were removed. The explants were graded for degree of bone formation by using manual palpation and radiographic and histological assessments.

Conclusions

By all methods of evaluation used, rhBMP-2 diluted with Omniscan was equivalent to rhBMP-2 diluted with sterile water in inducing bone formation. Both Conray and Optiray were shown to inhibit the osteoinductive potential of rhBMP-2.

Comments

Journal of Neurosurgery: Spine, Vol. 5, No. 5 (November 2006): 434-439. DOI.

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