Fig. 3.

nCeO₂ induces collagen I production from NHLFs, a hallmark of fibrosis, while amsCeO₂ does not. Primary human lung fibroblasts were treated with the indicated nanoparticle for 48 h. Western blot analysis with corresponding densitometry (a) and fluorescence microscopy (b) revealed a nCeO₂-induced increase in collagen I production, while the amorphous silica coating of nCeO₂ attenuated this observed effect on collagen production. SWCNTs and TGFβ (1 ng/mL) also significantly increased the expression of collagen I, as expected. (c) Alpha-smooth muscle actin staining of NHLFs that had been treated for 48 h with 0.2 μg/cm² of the indicated nanoparticle demonstrated that nCeO₂, as well as the Sigma CeO₂, SWCNTs, and TGFβ, increased expression of this myofibroblast marker. In contrast, the amsCeO₂, as well as the aSiO₂ control, expressed levels consistent with non-treated (NT) cells. Statistical significance is indicated as *p < 0.05 compared to NT conditions and #p < 0.05 for nCeO₂ compared to amsCeO₂