High-Performance Hybrid Bismuth–Carbon Nanotube Based Contrast Agent for X-ray CT Imaging

Abstract

Carbon nanotubes (CNTs) have been used for a plethora of biomedical applications, including their use as delivery vehicles for drugs, imaging agents, proteins, DNA, and other materials. Here, we describe the synthesis and characterization of a new CNT-based contrast agent (CA) for X-ray computed tomography (CT) imaging. The CA is a hybrid material derived from ultrashort single-walled carbon nanotubes (20-80 nm long, US-tubes) and Bi(III) oxo-salicylate clusters with four Bi(III) ions per cluster (BiC). The element bismuth was chosen over iodine, which is the conventional element used for CT CAs in the clinic today due to its high X-ray attenuation capability and its low toxicity, which makes bismuth a more-promising element for new CT CA design. The new CA contains 20% by weight bismuth with no detectable release of bismuth after a 48 h challenge by various biological media at 37 °C, demonstrating the presence of a strong interaction between the two components of the hybrid material. The performance of the new BiC@US-tubes solid material as a CT CA has been assessed using a clinical scanner and found to possess an X-ray attenuation ability of >2000 Hounsfield units (HU).

The Basic Properties of Gold Nanoparticles and their Applications in Tumor Diagnosis and Treatment

“…When the atomic number is higher than 53, the absorbed dose of the X-ray will increase [86]. Au has an atomic number of 79, which strongly increases the X-ray absorption coefficient [87]. This can minimize the damage of X-ray to normal tissues and becomes a promising radiotherapy sensitizer for oncotherapy [88].…”

Labeling Stem Cells with a New Hybrid Bismuth/Carbon Nanotube Contrast Agent for X-Ray Imaging

“…Bi 4 C@US-tubes were prepared as previously reported [56]. Briefly, the US-tubes and the Bi(III) oxo-salicylate cluster were prepared separately and then combined by simply sonicating both together for 1 h in dried tetrahydrofuran (THF).…”

Novel Bismuth‐Based Nanomaterials Used for Cancer Diagnosis and Therapy

“…More importantly, Bi 2 S 3 NPs have little cytotoxicity compared with free Bi 3+ at the same doses. Beside Bi 2 S 3 NMs, other Bi‐based NMs, such as bismuth oxyiodide (BiOI), bismuth oxychloride (BiOCl), bismuth selenide (Bi 2 Se 3 ), bismuth oxide (Bi 2 O 3 ), Cu 3 BiS 3 , bismuth subsalicylate, Bi III oxo‐salicylate clusters, and pure bismuth metal, have exhibited CT imaging ability. Among them, pure Bi NPs are a better choice to maximize the efficiency in X‐ray absorption due to the 100 % content of Bi element compared with other Bi‐based NMs (56.8 % for BiOI, 63.8 % for Bi 2 Se 3 , 81.3 % for Bi 2 S 3 , and 89.7 % for Bi 2 O 3 ).…”

“…As showni nF igure 2A,l ymph nodes can be clearly seen as indicatedb yw hite arrow after injection with Bi 2 S 3 NP suspension (equivalent to 11.4 mmol Bi 3 + ), whichp rovest hat Bi 2 S 3 NPs can be used for lymph-node delivery to improvec ancer staging. More importantly,B i 2 S 3 NPs have little cytotoxicity compared with free Bi 3 + at the same doses.B eside Bi 2 S 3 NMs, other Bi-based NMs, such as bismuth oxyiodide( BiOI), [14] bismuth oxychloride( BiOCl), [15] bismuth selenide (Bi 2 Se 3 ), [16] bismuth oxide (Bi 2 O 3 ), [17] Cu 3 BiS 3 , [18] bismuth subsalicylate, [19] Bi III oxo-salicylate clusters, [20] and pure bismuth metal, [21] have exhibited CT imag- [21a] have reported as imple non-injection methodt of abricateu niformly sized pure Bi NPs, which show high performance of CT imaging with excellent biocompatibility.…”