Subchronic oral toxicity evaluation of gold nanoparticles in male and female mice

Gold nanoparticles (AuNPs) are biocompatible nanomaterials with potential application in the food industry. The safety of AuNPs oral consumption remains inconclusive, and information on possible long-term toxicity is limited. The current study aimed to evaluate the subchronic oral toxicity of AuNPs in male and female Institute of Cancer Research (ICR) mice. Citrate-coated spherical AuNPs with 53 nm diameters were prepared and orally administered to the mice. No mortality or clinical abnormalities were observed following daily administration of AuNPs at the dosages of 0.2, 2, and 20 mg/kg for 90 days. There was no significant difference in body weight or the relative organs' weights between the control and AuNPs-treated mice. No gross abnormalities or histopathological changes were observed except that the male mice treated with high dose (20 mg/kg AuNPs) showed minor infiltration in the kidneys, and female mice showed a reduced A/G ratio and elevated platelet indices. Overall, the 90-day long-term oral consumption of AuNPs did not cause significant toxicity in mice.