Effect of Link N on mineral deposition by mesenchymal stem cells (MSCs) in osteogenic differentiation medium. (A) Alizarin red staining of mineral deposition in the extracellular matrix after MSCs were cultured in osteogenic differentiation medium without (control) or with Link N for 21 days. (B) The absorbance value of solubilized alizarin red measured at 620 nm. The results are shown as mean ± SD of three independent experiments with MSCs from three different donors. *P < 0.05 versus control.