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

Area of Science:

• Nanotoxicology
• Analytical Chemistry
• Materials Science

Background:

• Accurate detection and size characterization of nanoparticles (NPs) in biological tissues are crucial for nanotoxicology.
• Existing methods often require specific particle standards, limiting their applicability.
• There is a need for robust techniques to analyze NP behavior in complex biological matrices.

Purpose of the Study:

• To develop and validate a method for simultaneous localization and sizing of NPs in histological sections.
• To assess the stability and distribution of engineered NPs in biological tissues over time.
• To demonstrate the utility of laser ablation and single particle inductively coupled plasma-mass spectrometry (LA-spICP-MS) with liquid calibration for NP analysis.

Main Methods:

• Utilized laser ablation coupled with single particle inductively coupled plasma-mass spectrometry (LA-spICP-MS).
• Employed liquid calibration with dissolved metal standards via a pneumatic nebulizer.
• Analyzed silver nanoparticles (Ag NPs) and cerium dioxide nanoparticles (CeO₂ NPs) in gelatine standards, suspensions, and rat spleen cryosections.

Main Results:

• Transmission electron microscopy confirmed that NPs remained intact during the laser ablation process.
• The LA-spICP-MS method accurately determined NP size distribution in histological sections.
• Cerium dioxide nanoparticles (CeO₂ NPs) in rat spleen sections showed no size change over 3 weeks post-instillation, with smaller particles detected earlier.

Conclusions:

• LA-spICP-MS combined with dissolved metal standard calibration is a powerful tool for NP analysis in histological samples.
• The method allows simultaneous localization and sizing of NPs without the need for particle-specific standards.
• This technique provides valuable insights into NP behavior and distribution in biological systems for toxicological assessments.