Mass Cytometry Enabling Absolute and Fast Quantification of Silver Nanoparticle Uptake at the Single Cell Level

Abstract

In the last decades, significant efforts have been made to investigate possible cytotoxic effects of metallic nanoparticles (NPs). Methodologies enabling precise information regarding uptake and intracellular distribution of NPs at the single cell level remain to be established. Mass cytometry (MC) has been developed for high-dimensional single cell analyses and is a promising tool to quantify NP−cell interactions. Here, we aim to establish a new MC-based quantification procedure to receive absolute numbers of NPs per single cell by using a calibration that considers the specific transmission efficiency (TE) of suspended NPs. The current MC-quantification strategy accept TE values of complementary metal solutions. In this study, we demonstrate the different transmission behavior of 50 nm silver NPs (AgNP) and silver nitrate solution. We have used identical AgNPs for calibration as for in vitro-differentiated macrophages (THP-1 cell line) in a time-and dose-dependent manner. Our quantification relies on silver intensities measuring AgNPs in the same detection mode as the cells. Results were comparable with the TE quantification strategy using AgNPs but differed when using ionic silver. Furthermore, intact and digested cell aliquots were measured to investigate the impact of MC sample processing on the amount of AgNPs/cell. Taken together, we have provided a MC-specific calibration procedure to precisely calculate absolute numbers of NPs per single cell. Combined with its unique feature of multiplexing up to 50 parameters, MC provides much more information on the single cell level than single cell-inductively coupled plasma mass spectrometry (SC-ICPMS) and, therefore, offers new opportunities in nanotoxicology.

Analysis of Nanomaterials on Biological and Environmental Systems and New Analytical Methods for Improved Detection

“…As for the biological fates of nanoparticles, studies such as Turco et al [ 81 ] and López-Serrano Oliver et al [ 82 ] provide valuable insights into biological nanotoxicity testing. Turco et al utilized a sputtering-enabled intracellular X-ray photoelectron spectroscopy (SEI-XPS) method in which metallic NPs were cultured in media and cells before being directly measured for their internalization, stability, and oxidation state.…”

“…Utilizing this technique, Turco et al provided a possible method to help assess NPs integration, accumulation, and longevity and thus provide valuable insight into nanotoxicity. López-Serrano Oliver et al also looked at metal-based nanoparticles, in the form of silver, and focused on developing a new mass cytometry method that can quantify NPs numbers per single cell [ 82 ]. Although they made some interesting and important discoveries for new nanotoxicity analyses of NPs, there remains an issue with monitoring and intracellular uptake of NPs out of the mass range of mass cytometers.…”

Chemical Analysis of Single Cells and Organelles

“…In this technique, suspended cells are exposed to antibodies conjugated with isotopically labeled heavy metals; the antibodies label selected proteins, and ICP-MS analysis is then performed. López-Serrano Oliver et al used MC to establish a novel MC-based procedure to detect and quantify NPs in single THP-1 cells using a calibration method based on the transmission efficiencies of NPs . In this study, an MC-specific calibration procedure was developed to absolutely quantify NPs in single cells.…”

Toward High‐Dimensional Single‐Cell Analysis of Graphene Oxide Biological Impact: Tracking on Immune Cells by Single‐Cell Mass Cytometry

“…[ 34 ] A similar approach was used by Ivask et al and Oliver et al who applied mass cytometry for the detection of silver nanoparticles in T cells and macrophages, respectively. [ 35–37 ]…”