Fig. 4

The expression of aging-related genes, p16, p21, and p53, gradually increased with culture time. The expression of all three genes in ADMSCs in 2D culture was significantly higher than 3D at 14 days and 21 days. In contrast, the expression levels of stemness-related genes, Sox2, Oct4, Nanog, and c-myc, exhibited a decreasing tendency. Moreover, Oct4 and Nanog expression exhibited a more significant reduction in 2D culture than 3D cultures at 14 days and 21 days; besides, Sox2 and c-myc expression were significantly decreased in 2D cultures at 21 days. Data represented as average ± SD from n = 3 experiments, *p < 0.05, **p < 0.01, ***p < 0.001