The influence of the route of administration of gold nanoparticles on their tissue distribution and basic biochemical parameters: In vivo studies.

Background: The gold nanoparticles (AuNP's) exhibit interesting chemical and physical properties and for this reason are intensively tested in medicine. However there is a lack of information about toxicity of those nanoparticles as well as their excretion from the body. Thus, the aim of the present study was to investigate the influence of the route of administration of gold nanoparticles to rats on their distribution in tissues and excretion rate.

Methods: The experiment was carried out on male Wistar rats. The colloidal gold suspension containing 0.3619 mg of particles per milliliter, was administered per 1 kg of body weight. Serum levels of alanine aminotransferase, aspartate aminotransferase, total cholesterol, triglycerides, glucose and ferric reducing ability of plasma were measured in all investigated animals.

Results: It was shown that after oral administration only a small amount of AuNPs was absorbed. In addition, excretion of the metal during consecutive days after po or iv administration was examined. Moreover, the impact of AuNPs on some biochemical parameters 3 days after intravenous administration was studied. It was shown that the AuNPs are mainly cumulated in the liver, lungs and in spleen after iv administration and only slightly removed from the body in urine and feces.

Conclusion: Accumulation of those nanoparticles effect in increases of FRAP and glucose level up to 27% and 73%, respectively. This in turn suggests that iv administration of AuNPs may effect in serious medical complications. On the other site, the accumulation in the liver of about 50% of introduced particles to the rats body is promising for phototherapy and it opens "door" for drug transport to this organ.