Fig.  7.

Effects of NPs on chondrocytes. (A) qRT-PCR assay of IL-1β, IL-6, MMP-3, MMP-13, iNOS, TNF-α, ACAN, and Col2A1 in chondrocytes stimulated with the macrophage CM. (B) A DCFH-DA probe was utilized to detect the levels of ROS in chondrocytes exposed to the macrophage CM. (C) Quantitative analysis of intracellular ROS. (D) The secretion of MMP-13 in chondrocytes exposed to macrophage CM was measured by immunofluorescence staining and quantitative analysis of fluorescence intensity (E). Original magnification, 100×. Scale bar, 400 μm. n = 3. ^*P < 0.05, ^**P < 0.01, ^***P < 0.001.