Gold nanoparticles have been increasingly used in medicine lately to diagnose and treat diseases. However, researchers keep arguing their possible toxicity and ability to cause mutations. Experts at Razumovsky Saratov State Medical University; and the Institute of Biochemistry and Physiology of Plants and Microorg..., decided to check the influence of cold nanoparticles on the erythrocyte development process that can serve as an indicator of mutagenesis. The study was supported by the Russian Foundation for Basic Research, and the Federal Task Programs “The Development of Scientific Potential of Higher School of Educat... and “Scientific and Pedagogical Resources of Innovative Russia for 2009..., as well as a grant of the President of the Russian Federation.
Researches testing the toxicity of gold nanoparticles on animals are few and the results they show are inconsistent. The Saratov-based researchers used rats that they were feeding daily for seven days with collaurin particles 16 and 55 nanometer in diameter, as well as hollow silicon nanoparticles coated with gold 160 nanometer in diameter. The particle suspension was prepared by dissolving them in one millilitre of saline so that the gold swallowed by the rats weighed 57 microgram per day. After a week, immature polychromatocytes that did not yet lose their nuclei were taken from the red bone marrow — that serves to produce red blood cells — of the rats for analysis. The mutagenicity of the nanoparticles was assessed based on the appearance of the cells. That is a standard and relatively simple test used to check for mutagenicity — if the cells are influenced by mutagens they show additional micronuclei. The research showed that gold nanoparticles 16, 55 and 160 nanometer in diameter that were introduced in the body using the aforementioned approach did not cause mutations.
It is a known fact that the effect of the particles on the DNA depends on their size — the smaller the particle is the higher the probability for it to cause mutations. For example, tiny particles of 1.4 nanometer in diameter can bind with the DNA and affect genes. Bearing this in mind, the researchers believe that they need to continue their studies in order to gather more detailed information on possible toxic effect of gold nanoparticles of various sizes.
Source of information:
D. S. Dzhumgazieva at al.: “Studying the Mutagenic Action of Gold Nanoparticles in a Micronucleus Test.” The Bulletin Of Experimental Biology And Medicine, 2011, #6.