Gold nanoparticles-based SPECT/CT imaging probe targeting for vulnerable atherosclerosis plaques

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Radiochemistry

Background:

• Atherosclerotic plaques pose a risk, and identifying vulnerable ones is crucial.
• Dual-modal imaging offers enhanced accuracy for plaque evaluation.
• Targeting specific cellular markers like apoptotic macrophages can improve diagnostic specificity.

Purpose of the Study:

• To develop a novel dual-modal imaging probe for accurate localization and vulnerability assessment of atherosclerotic plaques.
• To conjugate gold nanoparticles (GNPs) with Annexin V and technetium-99m (Tc-99m) for SPECT/CT imaging.
• To target and visualize apoptotic macrophages within atherosclerotic lesions.

Main Methods:

• Synthesized Tc-99m labeled GNPs conjugated with Annexin V.
• Characterized the probe's size, labeling efficiency, and stability.
• Evaluated cellular uptake in apoptotic macrophages in vitro.
• Performed SPECT/CT imaging in ApoE knockout mice with diet-induced atherosclerosis.

Main Results:

• The synthesized probe ((99m)Tc-GNPs-Annexin V) exhibited uniform size and high labeling efficiency.
• The probe demonstrated enhanced uptake in apoptotic macrophages compared to controls.
• SPECT/CT imaging in vivo showed efficient accumulation in apoptotic macrophages and accurate lesion depiction.
• Imaging intensity correlated well with pathological changes.

Conclusions:

• Annexin V-modified hybrid gold nanoparticles were successfully synthesized as a SPECT/CT imaging probe.
• This dual-modal imaging system effectively targets apoptotic macrophages for better localization and diagnosis of vulnerable atherosclerotic plaques.
• The combined CT and SPECT imaging provides accurate lesion assessment and correlates with disease progression.