Nanotechnology offers numerous opportunities for invention of new and reformed applicable products for the benefit of human society. In spite of a vast application of nanomaterials there is little information about their impact on human health. This study examines the biological activity of nanosilver on mesenchymal, natural fibroblast (HF2), and osteoblast (G292) cells. The effects of nanosilver on the cells were observed by a light microscope and the amplification of the cells was assayed by using a standard cell toxicity test. The results show that the cytotoxicity depends on nanosilver concentration. The amount of IC50 on mesenchymal stem was 6.33; and on HF2 was 6.68; and on G292 cells was 3.42 ?g/L. The results show that nanosilver has two times more
of an inhibition effect on cancerous cells' growth as compared to the normal cells. This phenomenon is due to the direct effect of nanosilver on the cell oxidation system. Due to the extraordinary activation of the mitochondorial respiration system in cancer cells, when compared to the normal cells, it can provide suitable opportunity for nanosilver to cause cell disruption.