Iodinated polymer nanoparticles as contrast agent for spectral photon counting computed tomography

Area of Science:

• Nanotechnology
• Medical Imaging
• Polymer Chemistry

Background:

• Development of advanced contrast agents is crucial for enhancing medical imaging modalities like CT and SPCCT.
• Existing contrast agents face limitations regarding circulation time, toxicity, and quantification accuracy.
• Polymer nanoparticles offer a versatile platform for developing novel contrast agents with tunable properties.

Purpose of the Study:

• To evaluate iodinated polymer nanoparticles as contrast agents for CT and SPCCT.
• To assess the stability, biodistribution, and imaging performance of these nanoparticles in vivo.
• To explore the potential of SPCCT for accurate iodine quantification and material discrimination.

Main Methods:

• Synthesis of iodinated poly(vinyl alcohol) nanoparticles with high iodine content (71 wt%).
• Stabilization of nanoparticles using poly(caprolactone)-b-poly(ethylene glycol) for enhanced stability and stealth properties.
• Evaluation of radiopacity, stability in biological fluids, and in vivo performance in rat models using CT and SPCCT.

Main Results:

• Nanoparticles demonstrated high iodine content and excellent stability in water and human serum.
• PEGylation provided resistance to rapid clearance by the mononuclear phagocyte system, leading to long blood circulation.
• Intravenous injection in rats resulted in clear cardiovascular visualization for several hours, with subsequent liver and spleen accumulation.

Conclusions:

• The synthesized iodinated polymer nanoparticles are effective blood pool contrast agents for CT and SPCCT.
• Their long residence time in the bloodstream and tunable properties make them promising for cardiovascular imaging.
• SPCCT enables accurate iodine quantification and discrimination from other elements like gadolinium.