Micro-droplet-based calibration for quantitative elemental bioimaging by LA-ICPMS.

Area of Science:

• Analytical Chemistry
• Bioimaging
• Mass Spectrometry

Background:

• Quantitative elemental bioimaging is crucial for understanding biological processes and drug distribution.
• Traditional standardization methods can be time-consuming and limit throughput.
• Developing rapid and accurate quantification strategies is essential for advancing bioimaging applications.

Purpose of the Study:

• To evaluate a novel standardization strategy for quantitative elemental bioimaging using laser ablation-inductively coupled plasma-time-of-flight mass spectrometry (LA-ICP-TOFMS).
• To assess the performance of multi-point calibration with gelatin-based micro-droplet standards.
• To demonstrate the application of this method for analyzing metal-based anticancer drugs in complex biological models.

Main Methods:

• Utilized multi-point calibration with precisely deposited gelatin-based micro-droplet standards (400 ± 5 pL).
• Employed laser ablation-inductively coupled plasma-time-of-flight mass spectrometry (LA-ICP-TOFMS) with a low-dispersion setup.
• Achieved high-throughput analysis with pixel acquisition rates exceeding 200 Hz for rapid calibration and imaging.

Main Results:

• Demonstrated precise and accurate quantification of elements including platinum, phosphorus, copper, and zinc.
• Significantly reduced calibration time compared to conventional methods.
• Successfully applied the method to investigate the accumulation of metal-based anticancer drugs in multicellular tumor spheroids.

Conclusions:

• The developed micro-droplet standardization strategy enables high-throughput, quantitative elemental bioimaging comparable to solution-based methods.
• This approach offers a significant advancement for analyzing elemental distributions in biological samples, particularly for drug development and toxicology.
• The method provides a robust tool-set for investigating clinically relevant concentrations of therapeutic agents in complex biological systems.