PEG-modified gadolinium nanoparticles as contrast agents for in vivo micro-CT

Abstract

Vascular research is largely performed in rodents with the goal of developing treatments for human disease. Micro-computed tomography (micro-CT) provides non-destructive three-dimensional imaging that can be used to study the vasculature of rodents. However, to distinguish vasculature from other soft tissues, long-circulating contrast agents are required. In this study, we demonstrated that poly(ethylene glycol) (PEG)-coated gadolinium nanoparticles can be used as a vascular contrast agent in micro-CT. The coated particles could be lyophilized and then redispersed in an aqueous solution to achieve 100 mg/mL of gadolinium. After an intravenous injection of the contrast agent into mice, micro-CT scans showed blood pool contrast enhancements of at least 200 HU for 30 min. Imaging and quantitative analysis of gadolinium in tissues showed the presence of contrast agent in clearance organs including the liver and spleen and very low amounts in other organs. In vitro cell culture experiments, subcutaneous injections, and analysis of mouse body weight suggested that the agents exhibited low toxicity. Histological analysis of tissues 5 days after injection of the contrast agent showed cytotoxicity in the spleen, but no abnormalities were observed in the liver, lungs, kidneys, and bladder.

Heavily Gd-Doped Non-Toxic Cerium Oxide Nanoparticles for MRI Labelling of Stem Cells

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Perivascular adipose tissue in autoimmune rheumatic diseases

“…In contrast, micro-CT lacks sufficient resolution to accurately quantify PVAT inflammation in mice, given the small size of vasculature and the fast motion velocities. However, newly developed contrast agents such as poly-coated gadolinium nanoparticles can significantly improve the quality of images and may facilitate more detailed vascular imaging studies in the future [ 97 ].…”

Synthesis and Characterization of BaSO4–CaCO3–Alginate Nanocomposite Materials as Contrast Agents for Fine Vascular Imaging

“…Micro-CT allows for visualization and quantification of microscale vessels within intact tissue specimens of different organs . This strategy has been used to study the vasculature of the kidney, heart, and liver of rodents . Imaging soft tissues like vessels requires the use of a contrast agent, the composition and performance of which are critical for this imaging modality .…”

“… 3 This strategy has been used to study the vasculature of the kidney, heart, and liver of rodents. 4 Imaging soft tissues like vessels requires the use of a contrast agent, the composition and performance of which are critical for this imaging modality. 5 In addition, because of the narrower diameter of the vascular networks, it is challenging to inject contrast agents at the capillary levels of different organ systems.…”