Fig. 4

a Osteogenic marker expression of the non-primed/primed C3H10T1/2 cells seeded on Glass/GO slide. Real-time PCR was performed after 14 days of osteogenic medium culture on each groups (*p < 0.05, **p < 0.01). b Alizarin red staining of non-primed/primed cell on glass slide. Alizarin red staining was performed after 14 days of osteogenic medium culture. Scale bar = 100 μm. c ARS staining quantification of non-primed/primed cell on glass/GO slide. Absorbance at 405 nm, normalized by non-primed cell on glass slide (GLGM). The primed cell (CM) has more calcium deposition on it (**p < 0.01, ***p < 0.001)