Figure 1.

Effect of collagen aging on MCF-7 and ZR-75-1 luminal breast cancer cells growing on type I collagen 2D coating vs. 3D matrices. A. MCF-7 (left panel) and ZR-75-1 (right panel) cells were seeded on plastic (control) or in adult and old type I collagen 3D matrices at a density of 1.5 × 10⁴ cells/ml. B. MCF-7 (left panel) and ZR-75-1 (right panel) cells were seeded on plastic or on adult and old type I collagen 2D coating (5 µg/cm²) at a density of 1.5 × 10⁴ cells/ml. After 6 days of culture, viable cell density was evaluated by phase contrast microscopy. Values represent the mean ± S.E.M. of three independent experiments (**p < 0,01, ***p < 0.001, N.S = not significant).