This work is a systematic evaluation of the experimental parameters of the most widely used in vitro recombinant human bone morphogenetic protein-2 (rhBMP-2) activity assays. The variations in assays reported in the literature have challenged the reproducibility and translation of work using rhBMP-2 as a bone-inducing growth factor. By elucidating the effect of model cell line on the dose-dependent alkaline phosphatase response to rhBMP-2 induction and by establishing a correlation between protein activity and protein concentration by enzyme-linked immunosorbent assay using commercially available rhBMP-2, this work is a significant step toward developing an in vitro-in vivo correlation between quantified activity and clinical efficacy.
Keywords: BMP-2; alkaline phosphatase activity; bioactivity; bone regeneration.