Synthesis of PEG-Iodine-Capped Gold Nanoparticles and Their Contrast Enhancement in In Vitro and In Vivo for X-RayCT

Abstract EN

We designed gold nanoparticles (AuNPs) capped with iodine and polyethylene glycol (PEG) to provide effective enhancement for X-ray CT imaging.

The methoxy PEG-iodine-capped AuNPs were prepared through the chemisorption of iodine and substitution of methoxy PEG-SH onto the surface of gold nanoparticles, and severe aggregation in TEM was not observed.

The binding energies of Au 4f7/2 and I 3d5/2 of the methoxy PEG-iodine-capped AuNPs were obtained as 84.1 eV and 619.3 eV, respectively.

The binding energy shift of methoxy PEG-iodine-capped AuNPs would be resulted from the chemisorption between gold nanoparticles and iodine atoms.

The methoxy PEG-iodine-capped AuNPs have higher enhancement compared to PEG-capped gold nanoparicles in the same amount of gold in vitro.

After postinjection of methoxy PEG-iodine-capped AuNPs into the mice, dramatic contrast enhancement at the heart, aorta, liver, and kidney was observed, this was maintained up to 5 days, and there was no evidence of apparent toxicity.

In conclusion, methoxy PEG-iodine-capped AuNPs might be a good candidate as a CT contrast agent for blood pool imaging, and this will also contribute to the prolongation of a blood circulation time for X-ray CT imaging.