Hyaluronic Acid–Barium Tungstate Nanomedicine as Biosafety and High-Performance Binary Spectral CT Contrast Agents for Inflammatory Bowel Disease Detection

The direct visualization of the gastrointestinal tract is of vital significance for the examination of inflammatory bowel disease (IBD). However, present iodine- and barium-based contrast agents exert unsatisfactory imaging effects in the gastrointestinal tract and are not specific for inflammation. Herein, we designed and synthesized hyaluronic acid-barium tungstate nanoparticles (HA-BaWO4 NPs) for spectral CT imaging of IBD. HA-BaWO4 NPs displayed good in vitro imaging ability, low cytotoxicity, and high in vivo biocompatibility and were excreted from mice 24 h post-administration. Moreover, HA-BaWO4 NPs showed superior in vivo spectral CT imaging than the clinical contrast agent iohexol in the range of 40-160 keV, enabling clear visualization of gastrointestinal transit with stable signals at different voltage settings. More importantly, HA-BaWO4 NPs specifically accumulated in the inflamed region of the large intestine in DSS-induced colitis mice 24 h after administration, as confirmed by H&E staining showing severe inflammatory lesions. HA-BaWO4 NPs effectively differentiated colitis from the surrounding tissues, indicating their great potential for improving the sensitivity and accuracy of IBD diagnosis. We hope that the developed HA-BaWO4 NPs could serve as a promising nanoplatform for high-performance spectral CT imaging of IBD.