Gold Nanoparticle Parameters Play an Essential Role as CT Imaging Contrast Agents

Computed tomography (CT) is extensively used in clinical imaging modalities. There have recently been many reports to motivate for developing newer contrast agents. As a new contrast agent, gold nanoparticles (GNPs) have gained recent attention. In this paper, the effects of parameters related to gold nanoparticles (sizes, shapes, concentrations, and surface chemistries) on X-ray attenuation beam in human nasopharyngeal cancer cells were investigated. Hematoxylin and eosin (H&E), Colony, and MTT assays were applied to measure the compatibility of the NPs in cells. Our findings indicated that the GNPs with Au core sizes of ~13 nm and ~60 nm and polyethylene glycol covering on gold nanorods (PEG-GNRs) are non-cytotoxic and GNRs with an aspect ratio of 2.4 and 4.2 are toxic in a concentration range. At 80 kVp, GNPs (13 nm) enables 3.03–times higher contrast than iodine at a concentration of 5000 μM. The GNPs (13 nm) X-ray attenuations were 2.55-times and 1.63-times higher than PEG-GNRs and GNPs (60 nm) in cancer cells, respectively. X-ray attenuation highly increased when the concentration of mass (measured by ICP-OES) of NPs was elevated. In sum, smaller spherical GNPs can be proposed as an excellent possibility to Omnipaque for CT imaging of nasopharyngeal cancer cells.