Effect of CarMa source (fetal vs. adult), cell density, and exposure to IHH on mRNA expression of (a) Col X, (b) ALP, and (c) AGC of the encapsulated hMSCs incubated in chondrogenic medium/TGF-β1 with or without IHH for 21 days. Groups included 100 million cells/mL hMSCs in f-CarMa hydrogel with (f-100-IHH, solid black) or without (f-100, dashed black) IHH in the culture medium, 15 million cells/mL hMSCs in f-CarMa with (f-15-IHH, solid dark grey) or without (f-15, dashed dark grey) IHH, 100 million cells/mL hMSCs in a-CarMa with (a-100-IHH, solid medium grey) or without (a-100, dashed medium grey) IHH, 15 million cells/mL hMSCs in a-CarMa with (a-15-IHH, solid light grey) or without (a-15, dashed light grey) IHH. An asterisk (*) indicates a statistically significant difference (p < 0.05) between the test group and all other groups for a given time point. ALP, alkaline phosphatase.