Cryo-Fluorescence Tomography as a Tool for Visualizing Whole-Body Inflammation Using Perfluorocarbon Nanoemulsion...

Area of Science:

• Biomedical Imaging
• Nanotechnology
• Molecular Imaging

Background:

• Perfluorocarbon (PFC) nanoemulsions are utilized as imaging tracers.
• Validating tracer biodistribution is crucial for developing new imaging probes.
• Traditional histological methods can miss disseminated cell populations.

Purpose of the Study:

• To explore cryo-fluorescence tomography (CFT) for whole-body imaging of PFC nanoemulsion tracers.
• To assess CFT's utility in murine inflammation models.
• To streamline the development of novel in vivo imaging probes.

Main Methods:

• Intravenously administered fluorescent PFC nanoemulsions with distinct emission wavelengths.
• Whole-body cryo-fluorescence tomography (CFT) imaging of euthanized mice at high resolution (~50 µm voxels).
• Analysis of tracer localization in naïve mice and models of acute inflammation, colitis, and solid tumor.

Main Results:

• CFT visualized PFC nanoemulsions in reticuloendothelial system tissues and inflammatory lesions.
• Observed localization is consistent with immune cell (macrophage) labeling.
• Significant differences in CFT signals across wavelengths and tissues were noted, likely due to optical properties.

Conclusions:

• CFT is a valuable tool for validating PFC nanoemulsion biodistribution with high spatial resolution.
• CFT complements in vivo imaging techniques.
• This methodology bridges the resolution gap between in vivo imaging and histology.