Synthesis of diatrizoic acid-modified LAPONITE® nanodisks for CT imaging applications

Abstract

We report a novel iodinated computed tomography (CT) contrast agent, diatrizoic acid (DTA)-modified LAPONITE® (LAP) nanodisks for X-ray CT imaging applications. In this study, LAP was first silanized with aminopropyldimethylethoxysilane to render the particles with amine groups (LM–NH₂). Then, the LM–NH₂ nanoparticles (NPs) were conjugated with DTA via 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride coupling chemistry, followed by acetylation of the remaining amines of the LM–NH₂–DTA NPs to improve their cytocompatibility. The formed LM–NHAc–DTA NPs were characterized via different techniques. The results of the cell viability assay reveal that the LM–NHAc–DTA NPs are cytocompatible in the given concentration range of 0.1–1.0 mg mL⁻¹. The measurements of the X-ray attenuation coefficient demonstrate that the CT value of the LM–NHAc–DTA NPs is much higher than that of free DTA at the same iodine concentration. Notably, the acetylated LM–NHAc–DTA NPs showed a high performance in CT imaging of the major organs (heart, liver, and bladder) and a tumor model in vivo after intravenous injection. The developed LM–NHAc–DTA NPs may hold great promise to be used as a contrast agent for different CT imaging applications.