Exposure to gold nanoparticles produces cardiac tissue damage that depends on the size and duration of exposure

Background: Current research focuses on cancer therapy, diagnostics and imaging, although many challenges still need to be solved. However, for the application of gold nanoparticles (GNPs) in therapy and diagnostics it is necessary to know the bioaccumulation and local or systemic toxicity associated to them. The aim of the present study was to investigate the effects of intraperitoneal administration of GNPs on the histological alterations of the heart tissue of rats in an attempt to cover and understand the toxicity and the potential role of GNPs in the therapeutic and diagnostic applications. Methods: Animals were randomly divided into 3 GNPs-treated rats groups and one control group (CG). The 10, 20 and 50 nm GNPs were administered intraperitonealy at the rate of 3 or 7 days as follows: Group 1: received infusion of 100 mu l GNPs of size 10 nm for 3 or 7 days; Group 2: received infusion of 100 mu l GNPs of size 20 nm for 3 or 7 days; Group 3: received infusion of 100 mu l GNPs of size 50 nm for 3 or 7 days. Control group: received no GNPs. Results: In comparison with the respective control rats, GNPs-treated rat received 100 mu l of 10 and 20 nm particles for 3 days or 7 days demonstrating congested heart muscle with prominent dilated blood vessels, scattered and extravasations of red blood cells, focus of muscle hyalinosis, disturbed muscle fascicles, dense prominent focus of inflammatory cells infiltrate by small lymphocytes and few plasma cells while GNPs-treated rat received 100 mu l of 50 nm particles for 3 or 7 days demonstrating benign normal looking heart muscle with normal muscle direction and fascicles, and very few scattered small lymphocytes. Conclusions: The histological alterations induced by intraperitoneal administration of GNPs were size-dependent with smaller ones induced more affects and related with time exposure of GNPs. This study suggests that interaction of GNPs with proteins and various cell types might be evaluated as part of the toxicological assessment in addition to further experiments related to tissues antioxidant enzymes, oxidative parameters, lipid peroxidation, production of free radicals and/or ROS and cytokine, histomorphologcal and ultrastrucural will be performed to cover and understand the toxicity and the potential use of GNPs as therapeutic and diagnostic tool.