Research Article: Genotoxic Effects of Silver Nanoparticles on Mice in Vivo

Date Published: October , 2009

Publisher: A.I. Gordeyev

Author(s): C.G. Ordzhonikidze, L.K. Ramaiyya, E.M. Egorova, A.V. Rubanovich.

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Abstract

The toxic and genotoxic effects of silver nanoparticles were studied on injected mice (BALB/c line) in vivo. A water solution of silver nanoparticles (SNP) with particle sizes of 9±6 nm was obtained by means of the original method of biochemical synthesis. The effect of the SNP solution was compared to those of AOT (anionic surfactant used as SNP stabilizer) and silver nitrate (i.e. Ag+ ions) introduced as water solutions. In studies of the toxic effects, the death of mice was registered 12-24 hours after injection only at two maximum dozes of SNP (equivalent to 0.54 and 0.36 gAg/l). It is shown that the toxic effect decreases in the sequence SNP>AOT>>AgNO3. The LE50/30 values for SNP and AOT are equal to 0.30±0.07 gAg/l and 13.3±2.1 gAg/l, respectively. Genotoxic effects were assessed by the abnormal sperm heads test and neutral Comet assay. The frequencies of abnormal sperm heads (ASHs) did not differ after treatment by SNP and AOT, but both were significantly higher than those found with AgNO3 and in control mice. Comet assay showed an increase of the DNA percentage in the comet tail in spleen cells after the injection of SNP and AOT in concentrations of ≤ LE50/30. Tail DNA % was 32.8±1.3 and 26.3±1.7%, respectively, vs 16.2±0.7% for the untreated control. To sum up, these tests showed that the genotoxic effects of the SNP solution are associated with the presence of AOT rather than SNP.

Partial Text

The use of nanotechnological products in human activities has been steadily increasing in recent years. Because of this, it is of vital importance to study the biological effect of various nanoparticles and nanocomposite materials, and especially their effects on animal and human organisms. The main issue is to elicit the toxicity of nanoparticles for humans and thus, the potential risk in the use of nanoparticle- and particle-based products.

This work studied the toxic and genetic effects of silver nanoparticles (SNPs) on mice in vivo. We used water dispersions of SNPs obtained by biochemical synthesis [8]. The particle size was 9 ± 6 nm. It was previously shown that water dispersions showed a pronounced antibacterial and antiviral effect [9], as well as a strong antibiotic effect on the slime mold Physarum polycephalum [10].

This work shows for the first time that dispersed silver nanoparticles obtained via biochemical synthesis have a lethal effect on mamMalian organisms when injected in vivo. The lethal effect of the dispersed nanoparticles is approximately 4 times greater than that of the AOT dispersant alone (See Fig. 1), while injection of equivalent doses of silver ions is followed by 100% survival of the tested animals. Using a calculation taking into account the mouse’s body weight, we estimate that the dose of silver nanoparticles that causes 50% lethality is 1.9 ≤ 10-6 mg per gram of body mass.

This work was supported by funding provided by “Nanomet” in accordance with the RAmp;D (contract № 8418-16/09). The authors thank corresponding RAS member prof. N.K. Yankovskiy (IOGEN RAS) for thorough discussion of our results and V.S. Lysenkova, senior technician of the ecological genetics laboratory of IOGEN RAS for technical assistance in this project.

 

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