Effects of growth factors with NAC on trauma‐related alterations in gene expression of ECM components. Impacted human cartilage explants were continuously treated by growth factors and NAC (2 mM or 3.5 mM). 7 days post‐trauma, gene expression levels of ECM components (A) type I collagen (COL1A1), (B) type II collagen (COL2A1), (C) type X collagen (COL10A1) and (D) aggrecan (ACAN) were analysed by qRT‐PCR. T= traumatized, +I/B/F= stimulated by IGF‐1 (purple)/FGF18 (red)/BMP7 (green). Significant differences between groups were depicted as: [versus T] *P < 0.05, **P < 0.01, ***P < 0.001; ****P < 0.0001; [versus C] c= P < 0.05; [GF
versus
GF] $
P < 0.05, $$P < 0.01, $$$$
P < 0.0001. T: n ≥ 20; T+N: n ≥ 13 (2 mM), n ≥ 9 (3.5); T+N+I: n ≥ 13 (2 mM), n = 4 (3.5 mM); T+N+F: n ≥ 6 (2 mM), n = 5 (3.5 mM); T+N+B: n ≥ 8 (2 mM), n = 5 (3.5 mM).