The effects of nicotine on gingival fibroblasts in an in vitro wound healing model

Abstract

The purpose of this study was to ~nvestigate cell proliferation and wound repopulation by human gingival fibrobla~ts (GF) in the presence of nicotine in an in vitro wound-healing model. ·Tlle·hypothesis Jas that without nicotine present, GF and , . I . I periodontalligainent fibroblasts (PDLF) may have a greater proliferation rate and wound repopulation rate than do cells in the presence of nicotine. I - I .. Nicotine concentrations used wette 0, 1 f..LM, 1 mM, 2, 4, and 8 mM. The in vitro . I - wound healing model consisted of GF til~ seeded into twelve-well culture plates, grown to confluence, synchronized as to cell division and wounded using a rubber policeman. I I r Cells were fixed at 24-hour interval tim~ points, stained with crystal violet, and analyzed . I I with histomorphometry of microscopic ikages for wound repopulation. In other experiments, cells \Vere treated with BrdU and the absorbance determined with a ! spectrophotometer to ·estimate cell proli~eration. The nicotine challenge resulted in dose- . I i dependent resp~nses in all effects meas~red. Conclusions ·reached in this stud~ were as follows: ! 1) GF cells showed greater cell proliferation and cell migration rates than PDLF cells, . I as estimated by rate~ of confluency and ~igital images from light microscope. i 2) Vacuolization and other cytotoxic effects occurred with concentrations of 4-8 mM of nicotine in both cell types. 3)' There was a trend toward stimulato;rY e~fects at a low dose of nicotine. However, at higher concentrations, a dose-dependent; ipbibition in cell proliferation and cell migration · in GF cells was seen.