Effects of Nicotine on Stem Cell-Derived Osteoblast Migration

Objectives: The objective of this study was to determine if nicotine had an effect on the migration of osteoblasts in an in vitro scratch wound model. Methods: Adipose-derived adult stem cells (Zen-Bio, Research Triangle Park, NC) were cultured in 24 well plates in osteoblast differentiation medium with 0, 10, 20, 50, 100, or 200 μg/ml nicotine for seven days. At day eight a scratch wound was produced by dragging a pipet tip across the surface of the culture well. At 24 hours after wounding, the extent of cell migration from the wound edge was measured in arbitrary units using ImageJ (National Institutes of Health image processing program). Human dermal fibroblasts were similarly treated with nicotine and scratch-wounded in order to assay a second cell model. Data were analyzed using one way ANOVA with Tukey’s multiple comparison post-test and probability set at p < 0.05. Results: At 24 hours following wounding, the mean values +/- SEM for osteoblast migration from the wound edge (in arbitrary units) were as follows: control (775.3 +/- 29.9), 10 μg/ml nicotine (789.9 +/- 42.2), 20 μg/ml nicotine (689.5 +/- 35.4), 50 μg/ml nicotine (690.2 +/- 32.1), 100 μg/ml nicotine (666.1 +/- 27.5), and 200 μg/ml nicotine (559.4 +/- 23.6). Statistical analysis showed that the highest concentration of nicotine analyzed significantly inhibited osteoblast migration from the wound edge (p < 0.001). All other nicotine concentrations did not inhibit migration. A similar result was obtained when human dermal fibroblasts were analyzed. Fibroblasts treated with 200 μg/ml nicotine (952.3 +/- 19.5) demonstrated significantly decreased migration from a wound edge compared to control (1089.0 +/- 51.8, p < 0.05). Conclusions: Nicotine inhibits cell migration in a concentration-dependent manner. This has implications for the suppression of both connective tissue and bone wound healing in smokers.