Figure 5.

Cell proliferation and matrix production (sGAGs and hydroxyproline) by chondrocytes at day 7 in single-gradient (mechanical or CS) vs dual-gradient hydrogels. The amount of sGAG and hydroxyproline reported here is cell-deposited matrix, which is calculated by subtracting values of acellular hydrogels from cellular hydrogels. The comparison was performed at day 7 because CS only-gradient hydrogels fully degraded afterward. (A) Fold of cell proliferation normalized to day 1, (B) sGAG per wet weight, and (C) hydroxyproline per wet weight. Statistical analyses were performed between dual-gradient hydrogels vs mechanical only- or CS only-gradient hydrogels. Two-way ANOVA was performed followed by posthoc student’s t test corrected using the Benjamin-Hotchberg procedure (n = 3/group). *P < 0.01 compared to mechanical; #P < 0.01 compared to CS.