Colloidal Gold Nanoparticles as a Blood-Pool Contrast Agent for X-ray Computed Tomography in Mice

Abstract

To present the pharmacokinetics and computed tomographic imaging efficacy of colloidal gold nanoparticles (AuNPs) as a blood-pool agent for x-ray computed tomography (CT). To prepare the colloidal AuNPs, gold nanocrystals were modified using sulfhydrated polyethylene glycol (PEG). Cytotoxicity and histopathologic tests were carried out for toxicity evaluation. Six adult Balb/c mice underwent microcomputed tomography scans after injection of colloidal AuNPs (2.5 μmol Au/g body weight). Four mice with HT-1080 tumors were imaged for visualization of the tumor vasculature. The PEG coated colloidal AuNPs appeared as spherical nanoparticles with 38-nm diameters. The AuNPs-PEG showed a biocompatibility without toxicity in the mice. We identified a stable imaging window for visualizing the vasculature system, immediately to 24 hours after injection. Microcomputed tomography imaging using AuNPs-PEG clearly visualized the tumor vascular structures. Colloidal AuNPs show potential as a blood-pool agent for x-ray CT imaging.