A Correlative X‑ray Bioimaging Triad for Metals in Biomedical Research.

Area of Science:

• Biochemistry
• Biophysics
• Materials Science

Background:

• Metals are crucial for biological functions and are found throughout cells and tissues.
• Understanding metal roles in health, disease, and metallodrugs requires knowledge of their distribution and chemical state within biological systems.
• Current imaging methods often lack the resolution or specificity to fully characterize metal behavior in situ.

Purpose of the Study:

• To demonstrate how advanced biochemical imaging techniques can elucidate the spatial distribution, oxidation state, and coordination environment of metals in biological systems.
• To highlight the utility of synchrotron-based X-ray methods for studying metal function and the fate of metallodrugs.
• To discuss correlative imaging strategies for comprehensive analysis of metals in cells and tissues.

Main Methods:

• Utilizing a triad of synchrotron-based X-ray techniques: X-ray fluorescence (XRF) mapping, X-ray absorption spectroscopy (XAS), and cryogenic soft X-ray tomography (cryo-SXT).
• Employing XRF for nondestructive, multielemental imaging with sub-50 nm resolution.
• Applying XAS for site-specific electronic and structural speciation, and cryo-SXT for 3D ultrastructural imaging at ~40 nm resolution under near-native conditions.

Main Results:

• The combined use of XRF, XAS, and cryo-SXT enables detailed study of cellular and tissue heterogeneity.
• These techniques provide element-specific insights into metal transformations within biological environments.
• Correlative imaging strategies using cryo-preserved samples offer a comprehensive view of metal behavior.

Conclusions:

• The integration of XRF, XAS, and cryo-SXT under cryogenic conditions offers powerful capabilities for biomedical research.
• These advanced imaging approaches can accelerate breakthroughs in understanding metallodrug mechanisms and disease pathogenesis.
• Continued innovation in synchrotron technology will further enhance the application of this bioimaging triad in medicine.