Evaluation of a bioactive bone-inducing material consisting of collagen scaffolds and collagen-binding bone morphogenetic protein 2.

Bioactive bone-inducing material (BBIM) is a collagen-based scaffold composed of demineralized bone matrix and collagen-binding domain bone morphogenetic protein 2 (BMP-2). BBIM is regarded as a promising bone-inducing scaffold to repair bone defects. In this work, we evaluated the biocompatibility and osteogenecity of BBIM. Using enzyme-linked immunosorbent assay, the level of BMP-2 on BBIM was detected and considered adequate. Kunming mice were used as the animal model to investigate the acute systemic toxicity, long-term bone regeneration, ectopic bone formation, and chronic systemic toxicity. Results show that BBIM induced no serious inflammatory reaction or acute and chronic systemic toxicity. Our analyses also demonstrated significant homogeneous ectopic bone formation as well as significantly high numbers of erythrocytes in the BBIM groups in the chronic systemic toxicity study, a phenomenon which may provide indirect proof of the bone regeneration capacity of BBIM, which may be considered as a bioactivity indicator in future studies.