Cell Membrane-Functionalized Bismuth Oxyiodide Nanodots as Potential Contrast Agent for Gastrointestinal Tract Imaging

Various noninvasive imaging modalities, including X-ray and computed tomography (CT) imaging, have provided significant advantages in accurately assessing the conditions of the gastrointestinal (GI) tract. The corresponding contrast agent with high resolution and biosafety is one of the most crucial focuses in the diagnosis of GI diseases. In this study, considering the requirements of good biocompatibility and biosafety, a novel imaging platform composed of the high-performance contrast agent based on macrophage membrane-coated BiOI nanodots (BiOI@M) was designed via a facile approach. The BiOI@M exhibited outstanding long-term stability and low toxicity. Significantly, BiOI@M demonstrated superior imaging ability compared to clinical barium sulfate. Higher CT values of BiOI@M were observed at equivalent concentrations to barium sulfate, thereby clearly outlining the stomach, small intestine, caecum, and colon after the oral administration of BiOI@M solutions in X-ray and CT imaging. Taken together, BiOI@M could serve as a novel efficient contrast agent in X-ray/CT imaging of the GI tract and diagnosis of GI diseases.