Cytotoxic Effects of Gold Nanoparticles: A Multiparametric Study

Abstract

The in vitro labeling of therapeutic cells with nanoparticles (NPs) is becoming more and more common, but concerns about the possible effects of the NPs on the cultured cells are also increasing. In the present work, we evaluate the effects of poly(methacrylic acid)-coated 4 nm diameter Au NPs on a variety of sensitive and therapeutically interesting cell types (C17.2 neural progenitor cells, human umbilical vein endothelial cells, and PC12 rat pheochromocytoma cells) using a multiparametric approach. Using various NP concentrations and incubation times, we performed a stepwise analysis of the NP effects on cell viability, reactive oxygen species, cell morphology, cytoskeleton architecture, and cell functionality. The data show that higher NP concentrations (200 nM) reduce cell viability mostly through induction of reactive oxygen species, which was significantly induced at concentrations of 50 nM Au NPs or higher. At these concentrations, both actin and tubulin cytoskeleton were deformed and resulted in reduced cell proliferation and cellular differentiation. In terms of cell functionality, the NPs significantly impeded neurite outgrowth of PC12 cells up to 20 nM concentrations. At 10 nM, no significant effects on any cellular parameter could be observed. These data highlight the importance of using multiple assays to cover the broad spectrum of cell-NP interactions and to determine safe NP concentrations and put forward the described protocol as a possible template for future cell-NP interaction studies under comparable and standardized conditions.

The effect of nanoparticle degradation on poly(methacrylic acid)-coated quantum dot toxicity: The importance of particle functionality assessment in toxicology

“…Figure 7A,B reveals a concentration-dependent reduction in cell-spreading, which is in line with previous reports on various types of nanoparticles [36,42,43]. Please note that for these assays, only low QDot concentrations (up to 20 nM) were selected that do not induce significant levels of acute cell death as the occurrence of apoptotic bodies or condensed cells would substantially influence the results obtained.…”

Assessing nanoparticle toxicity in cell-based assays: influence of cell culture parameters and optimized models for bridging the in vitro–in vivo gap

“…Consensus on the optimal design of this multiparametric method has however not yet been reached, but several examples have been proposed recently, including one from our group that is displayed in figure 2 43,127 . Methods to evaluate the different parameters are preferably biochemical or microscopy-based assays as they are easily amendable for a future screening approach 128 .…”

The performance of gradient alloy quantum dots in cell labeling

“…In the present work, three different cell types are used (murine C17.2 neural progenitor cells, primary human umbilical vein endothelial cells (HUVEC) and rat PC12 pheochromocytoma cells) that have previously been shown to have a high potential in cell therapy and which are excellent models for different tissue types [38,39]. Cells that were transiently expressing lysosomal associated membrane protein 1 (Lamp1) fused with a fluorescent protein (green or red) as a marker for late endosomal and lysosomal compartments were exposed to the QDots at concentrations up to 50 nM for 24 h. Cells were then analyzed by confocal microscopy, where the colocalization of the QDots and the lysosomal marker was analyzed (Fig.…”

“…As NP toxicity is more closely correlated to the cellular NP level rather than the number of NPs originally administered to the cells [22], this would result in lower toxicity in PC12 cells. However, the PC12 cells, which are small cells with a limited cytoplasmic space, have been found to be very sensitive to cell stress [39]. Additionally, it has been shown that the size of the cell and its cytoplasm inversely correlates with the level of NP the cell can handle without any toxic effects [42].…”