In vivo real-time positron emission particle tracking (PEPT) and single particle PET

Area of Science:

• Biomedical Imaging
• Particle Physics
• Radiochemistry

Background:

• Positron emission particle tracking (PEPT) offers high-resolution 3D tracking of radiolabeled particles.
• Biomedical applications of PEPT are hindered by challenges in radiolabeling biocompatible particles and isolating single sub-micrometer particles.

Purpose of the Study:

• To develop methods for synthesizing and radiolabeling biocompatible nanoparticles for in vivo PEPT.
• To demonstrate the feasibility of in vivo PEPT and dynamic PET imaging of a single nanoparticle.

Main Methods:

• Synthesis and Gallium-68 (⁶⁸Ga) radiolabeling of homogeneous silica nanoparticles (950 nm diameter).
• Development of protocols for isolating and manipulating single radiolabeled nanoparticles.
• In vivo PEPT and dynamic positron emission tomography/computed tomography (PET/CT) imaging of a single nanoparticle in a preclinical model.

Main Results:

• Achieved unprecedented specific activities for ⁶⁸Ga-labeled silica nanoparticles (2.1 ± 1.4 kBq per particle).
• Successfully isolated and manipulated a single sub-micrometer radiolabeled particle.
• Demonstrated in vivo PEPT and dynamic PET/CT imaging of a single nanoparticle.

Conclusions:

• This study presents key advancements in nanoparticle radiolabeling and single-particle manipulation for PEPT.
• Enables quantitative, real-time, whole-body hemodynamic assessment in vivo.
• Offers a novel approach using minimal radioactive dose and material for preclinical research.