Comparative cytotoxic effect of citrate-capped gold nanoparticles with different sizes on noncancerous and cancerous cell lines

Gold nanoparticles (GNPs) have properties that can be applied to the diagnosis and therapies of cancer, improving both the control and efficiency of treatment. Therefore, the aim of this study was to synthesize and characterize GNPs of different sizes and evaluate their cytotoxicity in human erythrocytes, murine fibroblasts (NIH3T3), human cervix carcinoma cells (HeLa), and melanoma cells (B16F10). GNPs were successfully synthesized by the Turkevich method, to obtain citrate-capped GNPs with different sizes (10, 20, and 30 nm). Transmission electron microscopy images showed GNPs with spherical/near-spherical morphology and their sizes were confirmed by ultraviolet-visible spectroscopy analysis. FTIR and XRD spectra confirmed that the citrate-capped GNPs have been formed with appearance of peakscharacteristic. Cytotoxicity studies showed that the 20 nm GNPs exerted lower cytotoxic effects on noncancerous cells than other GNPs and presented a higher cytotoxic effect on the HeLa cells. In contrast, when GNPs were incubated with B16F10 cells, the 10 nm GNPs were more cytotoxic than the 20 and 30 nm GNPs. HeLa cells were more sensitive (IC50 2.1 μg/mL) to treatment with GNPs than B16F10 cells (IC50 > 70 μg/mL). Therefore, this study demonstrated that the physicochemical properties, concentration, and cell type used were limiting factors for the cytotoxic effect of GNPs. Lastly, these results confirm the need for future studies to evaluate cellular uptake, death mechanism, and other biochemical parameters required to develop novel cancer therapies.