Selective detection of inflammatory bowel disease in spectral CT imaging utilizing hyaluronic acid‑neodymium vanadate nanoparticles.

Selective detection of inflammatory bowel disease (IBD) could relieve the suffering of patients and reduce the risk of developing colorectal cancer. Spectral computed tomography (CT) imaging, an advanced CT modality, has the potential to achieve accurate diagnosis of gastrointestinal diseases with favorable soft-tissue contrast and unique k-edge imaging capacity. However, clinically available CT contrast agents exhibited suboptimal performance in spectral CT imaging and poor specificity for inflammatory lesions. Therefore, we developed hyaluronic acid-functionalized neodymium vanadate nanoparticles (HA-NdVO4 NPs) as biocompatible, CD44-targeted contrast agents to realize the specific detection of IBD. Leveraging higher k-edge value of neodymium, HA-NdVO4 NPs exhibited superior spectral CT imaging compared to clinically utilized iohexol, enabling clearer delineation and examination of gastrointestinal structures. Most HA-NdVO4 NPs were cleared within 24 h in healthy mice. Nevertheless, obvious nanoparticle accumulation and pronounced CT enhancement were observed in the inflamed colon region of colitis mice 24 h post administration, suggesting the excellent inflammation targeting ability of HA-NdVO4 NPs. Notably, spectral CT imaging provided brighter images and enhanced contrast at low monochromatic energies (40-60 keV), further improving the detection sensitivity of HA-NdVO4 NPs for IBD. Therefore, we believe that this contrast agent could advance the selective detection of IBD via spectral CT imaging.