Bio-Oss® modified by calcitonin gene-related peptide promotes osteogenesis in vitro

Bio-Oss (R) and alpha-calcitonin gene-related peptide (CGRP) are involved in osteogenesis. However, it has remained to be assessed how alpha-CGRP affects the effect of Bio-Oss. In the present study, primary osteoblasts were incubated with alpha-CGRP, Bio-Oss, alpha-GGRP-Bio-Oss or mimic-alpha-CGRP. The proliferation rate, mineralization nodules, alkaline phosphatase (ALP) activity and the expression of osteogenic genes were measured by a Cell Counting Kit-8 assay, Alizarin Red-S staining, ALP activity detection and reverse-transcription quantitative PCR as well as western blot analysis, respectively. The proliferation rate, ALP activity and the number of mineralization nodules were significantly increased in the alpha-CGRP-modified Bio-Oss group compared to that in the Bio-Oss group. The mRNA and protein levels of osteocalcin, Runt-related transcription factor-2 and ALP were significantly upregulated in the alpha-CGRP-Bio-Oss group compared with those in the Bio-Oss group. Furthermore, the effect of mimic-alpha-CGRP on osteogenesis was reduced as it carried a mutation. In conclusion, the present study was the first to demonstrate that Bio-Oss modified with CGRP contributed to osteogenesis and may provide a novel formulation applied in the clinic for restoration of large bone defects.