Impact of silver nanoparticles on human cells: Effect of particle size

Abstract

This work investigated the cytotoxicities of three silver nanoparticles (SNPs) SNP-5, SNP-20 and SNP-50 with different sizes (∼ 5 nm, ∼ 20 nm and ∼ 50 nm) using four human cell models (A549, SGC-7901, HepG2 and MCF-7). Endpoints included cell morphology, cell viability, cellular membrane integrity, oxidative stress and cell cycle progression. Observable deleterious effects on the cell morphologies and membrane integrity were induced by SNP-5 and SNP-20. SNPs elevated the ROS levels in cells and arrested the cells at S phase. Apoptosis occurred for 4–9% of the exposed cells. All these cellular responses as well as EC50 values were found to be size-dependent for the tested SNPs. Ultrastructural observations confirmed the presence of SNPs inside cells. Elemental analysis of silver in cells by ICP-MS showed that smaller nanoparticles enter cells more easily than larger ones, which may be the cause of higher toxic effects. The findings may assist in the design of SNP applications and provide insights into their toxicity.

Keywords::

• Silver nanoparticles
• cytotoxicity
• size-dependent

Declaration of interest: We are grateful to National Natural Science Foundation of China (20537020), Chinese Academy of Sciences (KZCXZ-YW-420-21) and Key Project in the National Science & Technology Pillar Program (2007BAC27B02-1a) for the financial support. The authors would like to report no conflict of interests. The authors are entirely responsible for the content and writing of the manuscript.