Nanophosphor-Based Contrast Agents for Spectral X-ray Imaging.
Lanthanide-based nanophosphors (NPhs) are herein developed as contrast agents for spectral X-ray imaging, highlighting the chemical, macromolecular and structural differences derived from ligand exchange on computed tomography (CT) and solvent dispersibility. Taking advantage of the ability of spectral X-ray imaging with photon-counting detectors to perform image acquisition, analysis, and processing at different energy windows (bins), enhanced signal of our K-edge materials was derived, improving sensitivity of CT imaging, and differentiation between water, tumor-mimic phantoms, and contrast materials. Our results indicate that the most effective of our oleic acid-stabilized K-edge nanoparticles can achieve 2-4x higher contrast than the examined iodinated molecules, making them suitable for deep tissue imaging of tissues or tumors. On the other hand, ligand exchange yielding poly(acrylic acid)-stabilized K-edge nanoparticles allows for high dispersibility and homogeneity in water, but with a lower contrast due to the high density of the polymer grafted, unless further engineering is probed. This is the first well-defined study that manages to correlate NPh grafting density with CT numbers and water dispersibility, laying the groundwork for the development of the next generation CT-guided diagnostic and/or theranostic materials.
['Smith|Kevin|K|', 'Getzin|Matthew|M|', 'Garfield|Josephine J|JJ|', 'Suvarnapathaki|Sanika|S|', 'Camci-Unal|Gulden|G|', 'Wang|Ge|G|0000-0002-2656-7705', 'Gkikas|Manos|M|']
nanophosphors computed tomography CT imaging X-ray contrast agents lanthanide nanoparticles rare earth metals spectral CT