EFFECTS OF SILVER NANOPARTICLES ON CELL VIABILITY OF NORMAL AND CANCER HUMAN SKIN CELLS

Abstract

Silver nanoparticles (AgNPs) are widely used in many areas such as medical and consumer products. The safety of the AgNPs however, is still questionable. Several studies reported that AgNPs are toxic to various cell types. Therefore, this study aimed to evaluate the effect of the AgNPs on viability of human skin normal cell line (CCD-986SK) and human skin cancer cell line (A375). The AgNPs were prepared by using silver nitrate (AgNO3) as the silver ion source, sodium borohydride (NaBH4) as the reducing agent and either alginate or poly (4-styrenesulfonic acid-co-maleic acid) sodium salt (Copss) as the stabilizing agent. The result showed that the synthesized AgNPs had the maximum absorbing wavelength in the range of 400-450 nanometers and 5-15 nanometers in size. Their zeta potential values were negative charge of -36.0 to -31.3 mV for AgNPs capped with alginate and -32.0 to -26.4 mV for AgNPs capped with Copss, indicating the presence of the anionic sodium alginate or Copss at the surface. The toxicity against CCD-986SK and A375 cells was assessed by the conventional 3-(4-,5-Dimethylthiazol-2-yl)-2, 5-diphenyltertrazolium bromide (MTT) assay. It was found that AgNO3 alone was highly toxic to both cell types while either alginate or Copss alone was not toxic. However, the alginate capped AgNPs were toxic to A375 cell line but not CCD-986SK cell line. In addition, the Copss capped AgNPs were toxic to A375 cell line and CCD-986SK only at low concentration of the Copss. Judging from the 50% inhibition concentration (IC50), it was found that A375 cell line was more sensitive to the AgNPs than the CCD-986SK cell line. The mode of cell death was investigated by Annexin V and propiodium iodide staining. AgNPs capped with both alginate and Copss was found to induce late apoptosis (84-90%) and necrosis (8-12%) in A375 cell line. Taken together, the AgNPs capped with alginate were less toxic than the AgNPs capped with Copss and the AgNPs capped with alginate were toxic to the skin cancer cell only. These results suggest that AgNPs may be useful as selective cancer therapeutice agent.