Figure 4From: Bioactive magnetic near Infra-Red fluorescent core-shell iron oxide/human serum albumin nanoparticles for controlled release of growth factors for augmentation of human mesenchymal stem cell growth and differentiationStability of free versus conjugated-FGF2. Ten ng/ml of free or conjugated FGF2 were incubated in various concentrations of fetal calf serum (0–100 %) in the medium at 37°C according to the experimental section. The residual concentrations of the growth factors following 1 and 7 days of incubation are shown in A and B, respectively.Back to article page