Concentration effect of gold nanoparticles on proliferation of keratinocytes.

34 nm gold nanoparticles with good stability were synthesized and characterized and their effect (as a function of concentration) on the proliferation of keratinocytes was evaluated by means of MTT and nucleolar organizer region (AgNOR) count (silver staining). The cell morphology was observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results demonstrate that a low concentration of gold nanoparticles enhances the proliferation of keratinocytes. Specifically, a concentration of 5.0 ppm gold nanoparticle has the best effect on the promotion of cell growth. In the experiment group, the AgNOR-positive areas and AgNOR area/nuclear area ratios of keratinocytes co-cultured with 5.0 ppm gold nanoparticles were greater than those in the control group (p<0.01). At a level greater than 10.0 ppm, gold nanoparticles were found to have a cytotoxic effect on keratinocytes. It is concluded that a low concentration of gold nanoparticles may be used as a biomedical material in skin tissue engineering.