Bismuth@US-tubes as a potential contrast agent for X-ray imaging applications

Abstract

The encapsulation of bismuth as BiOCl/Bi2O3 within ultra-short (ca. 50 nm) single-walled carbon nanocapsules (US-tubes) has been achieved. The Bi@US-tubes have been characterized by high-resolution transmission electron microscopy (HR-TEM), energy-dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Bi@US-tubes have been used for intracellular labeling of pig bone marrow-derived mesenchymal stem cells (MSCs) to show high X-ray contrast in computed tomography (CT) cellular imaging for the first time. The relatively high contrast is achieved with low bismuth loading (2.66% by weight) within the US-tubes and without compromising cell viability. X-ray CT imaging of Bi@US-tubes-labeled MSCs showed a nearly two-fold increase in contrast enhancement when compared to unlabeled MSCs in a 100 kV CT clinical scanner. The CT signal enhancement from the Bi@US-tubes is 500 times greater than polymer-coated Bi2S3 nanoparticles and several-fold that of any clinical iodinated contrast agent (CA) at the same concentration. Our findings suggest that the Bi@US-tubes can be used as a potential new class of X-ray CT agent for stem cell labeling and possibly in vivo tracking.

2D and 3D Coordination Networks of Polynuclear Bismuth Oxido/Hydroxido Sulfonato Clusters from Low Temperature Solid‐State Metathesis Reactions

“…Polynuclear bismuth oxido/hydroxido clusters are of great interest because they present an intermediate structural type spanning nanoscale proportions and nestling between mononuclear inorganic and metal–organic Bi III compounds and various phases of Bi 2 O 3 . As such, they have potential across a spectrum of applications, including: microelectronics, catalysis and catalyst precursors, luminescence, radio‐opaque polymers, and as X‐ray contrast agents in computed tomography …”

Hyaluronic acid-functionalized bismuth oxide nanoparticles for computed tomography imaging-guided radiotherapy of tumor

“…Moreover, various intrinsic limitations of CT imaging particularly with respect to inadequate soft tissue contrast, low-throughput capacity, limited accessibility, and ionizing radiation are also considered as notable hurdles that prevent the application of CT for clinical diagnosis. 19 To date, bismuth-based NPs (BiNPs) such as Bi 2 S 3 nanodots [20][21][22] and Bi 2 Se 3 nanoplates 23 have been employed as CT CAs which are commonly used in clinical imaging. Moreover, BiNPs have received wide attention in the field of radiotherapy research due to their remarkable radiation dose enhancement under kilovolt-energy X-ray beams, which is significantly higher than the well-known gold radiation sensitizer.…”

Synthesis, characterization, in vitro phantom imaging, and cytotoxicity of a novel graphene-based multimodal magnetic resonance imaging-X-ray computed tomography contrast agent

“…55 Their phantom imaging studies illustrated that the CT coefficient value of Bi@US-tubes suspensions in Pluronic® F-108 NF was 1079 HU per mM, which is higher than the radiodensity of rGNP-HI. However, the results of our study cannot be directly compared to theirs, due to differences in the morphology of carbon nanostructures (graphene vs. US-tubes) and radio-opaque elements (iodine, manganese vs. bismuth).…”