Calibration Strategy to Size and Localize Multi-Shaped Nanoparticles in Tissue Sections Using LA–spICP–MS

Abstract

In the field of nanotoxicology, the detection and size characterization of nanoparticles (NPs) in biological tissues become increasingly important. To gain information on both particle size and particle distribution in histological sections, laser ablation and single particle inductively coupled plasma–mass spectrometry (LA–spICP–MS) was used in combination with a liquid calibration of dissolved metal standards via a pneumatic nebulizer. In the first step, the particle size distribution of Ag NPs embedded in matrix-matched gelatine standards introduced via LA was compared with that of Ag NPs in a suspension and nebulizer-based ICP–MS. The data show that the particles remained intact by the ablation process as confirmed by transmission electron microscopy. Moreover, the optimized method was applied to CeO2 NPs that are highly relevant for (eco-)­toxicological research but, unlike Ag NPs, are multi-shaped and have a broad particle size distribution. Upon analyzing the particle size distribution of CeO2 NPs in cryosections of rat spleen, CeO2 NPs were found to remain unchanged in size over 3 h, 3 d, and 3 weeks post-intratracheal instillation, with the fraction of smaller particles reaching the spleen first. Overall, LA–spICP–MS combined with a calibration based on dissolved metal standards is a powerful tool to simultaneously localize and size NPs in histological sections in the absence of particle standards.

Atomic spectrometry update: review of advances in the analysis of clinical and biological materials, foods and beverages

“…Continuing on the theme of calibration approaches for LA-ICP-MS , several papers have focused on this challenge. Seiffert et al 176 developed a strategy to determine the location and size of nanoparticles in the tissues. The first consideration was whether the ablation process caused disintegration of the NPs which would affect the size distribution.…”

Improving detection thresholds and robust event filtering in single-particle and single-cell ICP-MS analysis

“…In recent publications, it has been applied to answer complex ecological and toxicological questions with nanoparticles (NPs) of mixed composition or high polydispersity, and various surface modifications. 1–5 A promising variant of sp-ICP-MS is the analysis of biological cells, which enables the detection of chemical elements at the single-cell (sc) level. It is referred to as sc-ICP-MS. Due to challenges in cell handling, a lot of progress has been achieved through the optimization of sample introduction and preparation.…”