Toxicity of Gold Nanoparticles Functionalized with Cationic and Anionic Side Chains

TLDR

Gold nanoparticles are valuable for diverse biological applications, but high concentrations can cause toxicity. The authors employed MTT, hemolysis, and bacterial viability assays on 2‑nm gold nanoparticles, and dye‑release studies with lipid vesicles revealed concentration‑dependent lysis driven by electrostatic binding as the likely mechanism of cationic particle toxicity. Cationic gold nanoparticles exhibit moderate toxicity while anionic ones are largely nontoxic, with concentration‑dependent lysis via electrostatic binding explaining the observed toxicity.

Abstract

The structure and properties of gold nanoparticles make them useful for a wide array of biological application. Toxicity, however, has been observed at high concentrations using these systems. MTT, hemolysis, and bacterial viability assays were used to explore differential toxicity among the cell types used, using 2 nm core particles. These studies show that cationic particles are moderately toxic, whereas anionic particles are quite nontoxic. Concentration-dependent lysis mediated by initial electrostatic binding was observed in dye release studies using lipid vesicles, providing the probable mechanism for observed toxicity with the cationic MMPCs.