Fig. 7

GAGs restrict the diffusion gradient of FGF10. a A hydrogel cell culture system was built to mimic the ECM environment. BaF3-FGFR2b cells were embedded in hydrogel with or without GAGs and cultured in RPMI1640 media. Cultures without GAGs in the hydrogel were divided into blank control or FGF10 control according to the presence or absence of 1000 pM FGF10 in the culture medium. The experimental groups were supplemented with 1000 pM FGF10 in the culture medium plus 1 μg/ml, 3 μg/ml, or 5 μg/ml of GAGs in the hydrogel. After 48 h of culture, the FGF activity of each group was calculated based on the viability of BaF3-FGFR2b cells (see Additional File 10: Fig. S10). b Cultures with GAGs in the hydrogel without FGF10 in the medium showed no significant differences from the blank control, indicating that GAGs alone did not affect the viability of BaF3 cells. c, d GAGs at 1 μg/ml and 3 μg/ml concentrations displayed differential config effects on FGF reactivity. e GAGs at 5 μg/ml showed nearly equal confining effects on FGF reactivity. The cell viability of each experimental group (named after supplemented GAGs) was compared with FGF control by 2-sample t tests. Data are mean ± SD (n = 3). *P < 0.05 indicates a significant difference between experimental group and FGF10 Control