Nanotoxicity of Inert Materials: The Case of Gold, Silver and Iron

Abstract

-Nanotechnology has opened a new horizon of research in various fields including applied physics, chemistry, electronics, optics, robotics, biotechnology and medicine. In the biomedical field, nanomaterials have shown remarkable potential as theranostic agents. Materials which are considered inert are often used in nanomedicine owning to their nontoxic profile. At nanoscale, these inert materials have shown unique properties that differ from bulk and dissolved counterparts. In the case of metals, this unique behavior not only imparts paramount advantages but also confers toxicity due to their unwanted interaction with different cellular processes. In the literature, the toxicity of nanoparticles made from inert materials has been investigated and many of these have revealed toxic potential under specific conditions. The surge to understand underlying mechanism of toxicity has increased and different means have been employed to overcome toxicity problems associated with these agents. In this review, we have focused nanoparticles of three inert metallic materials i.e. gold, silver and iron as these are regarded as biologically inert in the bulk and dissolved form. These materials have gained wider research interest and studies indicating the toxicity of these materials are also emerging. Oxidative stress, physical binding and interference with intracellular signaling are the major role player in nanotoxicity and their predominance is highly dependent upon size, surface coating and administered dose of nanoparticles. Current strategies to overcome toxicity have also been reviewed in the light of recent literature. The authors also suggested that uniform testing standards and well-designed studies are needed to evaluate nanotoxicity of these materials that are otherwise considered as inert.

Solid lipid nanoparticles for thermoresponsive targeting: evidence from spectrophotometry, electrochemical, and cytotoxicity studies

“…27 Second, nanoparticles production should be homogenous for better performance in vitro and in vivo. 28 On the other hand, zeta potential is important with respect to colloidal stability of the SLNs. Nanoparticles with a zeta potential between 20 and 40 mV will have sufficient repulsion to remain homogeneously dispersed in the aqueous dispersion.…”

Novel route synthesis of porous and solid gold nanoparticles for investigating their comparative performance as contrast agent in computed tomography scan and effect on liver and kidney function

“…Lack of toxicity has been broadly documented for negatively charged GNPs (probably due to their bare surface) in the size range reported in this paper and at a dose of 1 mg/kg. 27 Thus, it could be assumed that lecithin-coated PGNPs and SGNPs could be safely used in vivo as preferred contrast agents.…”

“…However, application of these gold nanostructures has been limited by the complex manufacturing procedure, high cost, and toxicity due to surface ligands. 27 In this paper, we report a novel route for one-pot synthesis of solid gold nanoparticles (SGNPs) and PGNPs as CT contrast agents. Both SGNPs and PGNPs were prepared and stabilized with lecithin.…”

Study of Protective Effects of Gold Nano Particles on the Liver Toxicity Induced by Carbon-Tetrachloride (CCl4) in Male Rats

“…Gold nanoparticles are usually used in food packaging, drinks, toothpaste, cars, and lubricants [13]. Umair M, et al (2016) considered that nanoparticles of gold are observed as biologically inert [14]. Nanoparticles (NPs) have specific properties which make them suitable for imaging, therapy, and drug delivery [15].…”

“…Nanoparticles (NPs) have specific properties which make them suitable for imaging, therapy, and drug delivery [15]. According to the above mentioned report [14] and since gold nanoparticle of AuNP has shown anti-oxidant activity, this trail was designed to assess the antioxidant effect of AuNP on the liver toxicity induced by carbon -tetrachloride (CCl 4 ) in male rats.…”