How toxic are gold nanoparticles? The state-of-the-art

Abstract

With the growing interest in the applications of gold nanoparticles in biotechnology and their physiological effects, possible toxicity of gold nanoparticles is becoming an increasingly important issue. A large number of studies carried out over the past few years under a variety of experimental conditions and following different protocols have produced conflicting results, leading to divergent views about the actual safety of gold nanoparticles in human applications.This work is intended to provide an overview of the most recent experimental results and thereby summarize current state-of-the-art. Rather than presenting a comprehensive review of the available literature in this field, which would be impractically broad, we have selected representative examples of both in vivo and in vitro studies, which clearly demonstrate the need for urgent and rigorous standardization of experimental protocols. Despite their significant potential, the safety of gold nanoparticles is highly controversial at this time, and important concerns have been raised that need to be properly addressed. Factors such as shape, size, surface charge, coating, and surface functionalization are expected to influence the interactions of particles with biological systems to a different extent, resulting in different outcomes and influencing the potential of gold nanoparticles for biomedical applications.Moreover, despite continuous attempts to establish a correlation between structure of the particles and their interactions with biological systems, we are still far from elucidating the toxicological profile of gold nanoparticles in an indisputable manner. This review is intended to contribute towards this goal, offering a number of suggestions on how to achieve the systematization of data on the most relevant physico-chemical parameters, which govern and control the toxicity of gold nanoparticles at cellular and whole-organism levels.

Bioconjugated gold nanoparticles enhance cellular uptake: A proof of concept study for siRNA delivery in prostate cancer cells

“…In the LNCaP cell line, AuNPs-PEGTf, AuNPs-PEI and AuNPs-PEI-FA displayed IC50 values of 103, 118 and 110 μg mL −1 respectively. Similar data were also observed in PC-3 cells, with IC50 values of 107, has been reported that toxicity of AuNPs is dependent on particle size, surface charge, morphology, surface chemistry, ligand types and the mechanisms of cellular uptake [29].…”

Analysis of poration-induced changes in cells from laser-activated plasmonic substrates

“…Gold nanoparticles potentially outperform other physical techniques by offering high efficiency, viability, and throughput [21,28,29]. However, nanoparticles are sometimes ingested into the cell, which can have unwanted side effects at high concentrations [17,20,[30][31][32]. Plasmonic substrate-based methods operate with the same physical poration mechanism as plasmonic nanoparticles but use lithography techniques to precisely pattern a surface of nanostructures that are not ingested by the cell.…”

Biosynthesis of gold nanoparticles by the extreme bacterium <em>Deinococcus radiodurans</em> and an evaluation of their antibacterial properties

“…52,54,55 However, the relatively inert AuNPs with appropriate coating are thought to have no side effects on human health. [56][57][58] Moreover, the AuNPs used in the present study were obtained from the nonpathogenic bacterium D. radiodurans, and the antibacterial activities of these AuNPs have potential biomedical applications.…”