Acute and subchronic dermal toxicity of nanosilver in guinea pig

Abstract

M Korani1, SM Rezayat1,2,4, K Gilani3, S Arbabi Bidgoli4, S Adeli11Department of Pharmacology, Faculty of Medicine, Tehran University of Medical Sciences; 2Department of Nanotechnology, Faculty of Advanced Sciences and Technology in Medicine, Tehran University of Medical Sciences; 3Department of Pharmaceutics, Faculty of Pharmacy, Tehran University of Medical Sciences; 4Department of Toxicology & Pharmacology, Faculty of Pharmacy, Pharmaceutical Sciences Branch, Islamic Azad University (IAUPS), Tehran, IranAbstract: Silver has been used as an antimicrobial agent for a long time in different forms, but silver nanoparticles (nanosilver) have recently been recognized as potent antimicrobial agents. Although nanosilver is finding diverse medical applications such as silver-based dressings and silver-coated medical devices, its dermal and systemic toxicity via dermal use has not yet been identified. In this study, we analyzed the potential toxicity of colloidal nanosilver in acute and subchronic guinea pigs. Before toxicity assessments, the size of colloidal nanosilver was recorded in sizes <100 nm by X-ray diffraction and transmission electron microscopy. For toxicological assessments, male guinea pigs weighing 350 to 400 g were exposed to two different concentrations of nanosilver (1000 and 10,000 µg/mL) in an acute study and three concentrations of nanosilver (100, 1000, and 10,000 µg/mL) in a subchronic study. Toxic responses were assessed by clinical and histopathologic parameters. In all experimental animals the sites of exposure were scored for any type of dermal toxicity and compared with negative control and positive control groups. In autopsy studies during the acute test, no significant changes in organ weight or major macroscopic changes were detected, but dose-dependent histopathologic abnormalities were seen in skin, liver, and spleen of all test groups. In addition, experimental animals subjected to subchronic tests showed greater tissue abnormalities than the subjects of acute tests. It seems that colloidal nanosilver has the potential to provide target organ toxicities in a dose- and time-dependent manner.Keywords: nanosilver, acute dermal toxicity, subchronic dermal toxicity