Figure 5
Effect of SWCNT on fibroblast collagen production. Subconfluent cultures of human lung fibroblast CRL-1490 cells were either left untreated (No Tx) or treated with Survanta® alone, Survanta®-dispersed SWCNT (SD-SWCNT), Survanta®-dispersed ultrafine carbon black (SD-UFCB), or acetone/sonication-dispersed SWCNT (AD-SWCNT) at a particle concentration of 0.02 μg/cm2 or 0.04 μg/ml. At 2 days after the treatment, cells were washed, lysed, and analyzed for total collagen content by the Sircol® assay (A) or collagen I expression by Western blotting (B), as described in the Methods section. Equal amounts of total protein per sample were used in all measurements. β-actin was used as a loading control for Western blotting. The blot signals were quantified by densitometry and mean data from independent experiments (one of which is shown here) were normalized to the result obtained in cells without treatment. Plots are mean ± S.D. (n = 4). *p < 0.05 versus non-treated control.