The Effect of Gold Nanoparticle Size in the Cellular Uptake

Abstract

Nowadays, gold nanoparticles (AuNPs) received a great deal of attention for biomedical applications especially in diagnostic imaging and therapeutics. In this study, we elucidate on how size of gold nanoparticles (AuNPs) affect cellular uptake. The size dependence of AuNPs cytotoxicity in MCF-7 cells was tested by using the WST-1 assay. The sizes of AuNPs tested were 13 nm, 50 nm, and 70 nm. The toxicity of AuNPs in MCF-7 cell lines was quantified by determining the IC50 values in WST-1 assays. The IC50 values (inhibitory concentrations that affected 50% growth inhibition) of 13 nm AuNPs is higher than 50 nm and 70 nm AuNPs. Mean that, 13 nm AuNPs is less toxic to MCF-7 cells. This cytotoxicity results generally agree with those obtained in the study of cellular uptake by Inverted Microscope and EFTEM. Morphological observation of MCF-7 after being treated with 13 nm, 50 nm, and 70 nm AuNPs, were looking unhealthy and dying out of the populace, the observed cells were more reduced and dying as treatment with 50 nm and 70 nm AuNPs. Cells detachment, clumping, shrunken, and dispersed cells in the culture medium and floating cells were also observed. The observed morphological changes increase in 50 nm and 70 nm AuNPs than in 13 nm AuNPs, which is less toxic to MCF-7 cells. The presented morphological analysis has also established that 13 nm AuNPs showed less toxic to MCF-7 cells. The presented results clearly indicate that the cytotoxicity and cellular uptake of AuNPs depend on the size of the nanoparticles.