Spatial Profiling of Elements through Matrix-Assisted Laser Desorption Ionization Mass Spectrometry Imaging

Area of Science:

• Analytical Chemistry
• Biomedical Imaging
• Mass Spectrometry

Background:

• Matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI MSI) is primarily used for biomolecular mapping.
• Established elemental imaging techniques like LA-ICP-MS and SIMS cannot simultaneously map elements and biomolecules.
• There is a need for methods that integrate atomic and biomolecular spatial information.

Purpose of the Study:

• To demonstrate the feasibility of MALDI MSI for direct spatial element profiling.
• To optimize MALDI MSI parameters for sensitive element detection.
• To showcase the integration of elemental and biomolecular imaging.

Main Methods:

• Optimized MALDI MSI parameters (laser power, ionization, mass resolving power) for element detection (Fe, Ca, Gd, Pt, Cl).
• Utilized high-resolution FTICR-MS and timsTOF MSI for assessing performance.
• Applied the method to murine developmental models, genetic disorders, and chemotherapy distribution studies.

Main Results:

• Successfully detected endogenous and exogenous elements using MALDI MSI.
• Demonstrated preservation of spatial integrity during element imaging.
• Confirmed the reliability of isotopologue distributions through computational modeling and spectral analysis.

Conclusions:

• MALDI MSI is a viable alternative for high-resolution element imaging.
• This method complements LA-ICP-MS and SIMS by integrating atomic and biomolecular data.
• Expands MALDI MSI capabilities for metallomics, pharmacokinetics, and disease biomarker research.