The effect of gold nanoparticles on the proliferation and differentiation of murine osteoblast: a study of MC3T3-E1 cells in vitro.

The current study involves in identification and molecular levels characterization of optimal size and concentration of gold nanoparticles (AuNPs). Stable, gold nanoparticles were synthesized and characterized using transmission electron microscopy (TEM) and dynamic light scattering (DLS). The concentration and size dependent effects of the gold nanoparticles on proliferation of pre-osteoblast cells MC3T3-E1 was evaluated employing MTT cell proliferation assay. The results revealed that 30 nm diameter gold nanoparticles at a concentration of 10(-11) ppm were the most effective in promoting cell proliferation. Assay for alkaline phosphatase (ALP) activity and ALP staining were also used to confirm the effect of gold nanoparticles on osteoblast proliferation and differentiation. Moreover, reverse transcriptase polymerase chain reaction (RT-PCR) was used to measure the expression of the osteogenic genes Runx2, ALP, OCN and OPN as response gold nanoparticles. The data demonstrated that 30 nm gold nanoparticles at a concentration of 10(-11) ppm was the best combination of size and concentration to promote the proliferation and differentiation of osteoblasts, as indicated by an increase in the ALP activity and expression of the osteogenic genes Runx2, ALP, OCN and OPN. Collectively the results of this study suggest that gold nanoparticles can promote the proliferation and differentiation of osteoblasts and could be used effectively in treatments promoting bone regeneration.