MC3T3-E1 cell number measured by CellTiter 96® AQueous assay in the presence of BL, 4ZN, and 5ZN disks, loaded or not with 100 nM osteostatin, after 2 days (A) and 5 days (B) of culture. Absorbance was measured at 490 nm, directly proportional to the number of living cells. Runx2 mRNA levels measured by real-time PCR (C), ALP activity (D), and matrix mineralization measured by Alizarin red staining (E) in MC3T3-E1 cells in the presence of these materials at 5 days (C,D) and 12 days (E) of culture. For mineralization studies, absorbance was measured at 620 nm. Results are means ± SEM of three measurements in triplicate (* p < 0.05) vs. corresponding unloaded disks.