Size‐dependent cellular toxicity of silver nanoparticles

Abstract

Silver nanoparticles (AgNPs) have found a variety of uses including biomedical materials; however, studies of the cytotoxicity of AgNPs by size effects are only in the beginning stage. In this study, we examined the size‐dependent cellular toxicity of AgNPs using three different characteristic sizes (∼ 10, 50, and 100 nm) against several cell lines including MC3T3‐E1 and PC12. The cytotoxic effect determined based on the cell viability, intracellular reactive oxygen species generation, lactate dehydrogenase release, ultrastructural changes in cell morphology, and upregulation of stress‐related genes (ho‐1 and MMP‐3) was fairly size‐ and dose‐dependent. In particular, AgNPs stimulated apoptosis in the MC3T3‐E1 cells, but induced necrotic cell death in the PC12 cells. Furthermore, the smallest sized AgNPs (10 nm size) had a greater ability to induce apoptosis in the MC3T3‐E1 cells than the other sized AgNPs (50 and 100 nm). These data suggest that the AgNPs‐induced cytotoxic effects against tissue cells are particle size‐dependent, and thus, the particle size needs careful consideration in the design of the nanoparticles for biomedical uses. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.