Fig. 5.

(A) Stereoscope and microscopic images of BMSCs stimulated with 1 ng/ml IL-1β co-stained with ALP and DAPI. (B) Images of chondrocytes stimulated with 1 ng/ml IL-1β stained with Alcian blue. (C) Quantification of ALP staining. (D) The number of ALP positive-stained cells. (E) Quantification of Alcian blue staining. Gene expression levels of osteogenic associated genes COL I (F) and RUNX2 (G) were measured at day 7. The grayscale maps of western blots for BMSC (H) and the corresponding quantification for Col I (I), RUNX2 (J) at day 7. Gene expression level of chondrocyte phenotype associated genes COL-2 (K) and SOX-9 (L) was measured with qPCR at day 5. The grayscale maps of western blots for chondrocyte (M) and the corresponding quantification for Col-2 (N), SOX-9 (O) at day 5. Gene expression level of ECM degradation-related enzyme ADAMTS5 (P) was measured with qPCR. Gene expression levels of Nrf2 pathway-related genes NRF2 (Q), SOD-1 (R) and HO-1 (S) were measured with qPCR at day 5. (T) The proposed model for the protective effect of CuTA@SF in OCD, wherein it inhibited ECM degradation induced by IL-1β via the Nrf2/SOD-1, HO-1 pathway. The effects of CuTA@SF on BMSCs osteogenesis and chondrocyte phenotype maintaining. Results were shown as mean ± SD. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.