Jun 12, 2014
Modifying bismuth sulfide for biocompatible CT imaging
With the largest atomic number and X-ray attenuation coefficient, Bi2S3 may be the most promising computed tomography (CT) contrast agent among the metal-based nanoparticles. However, the need for surface modification and biocompatibility is limiting its application as a CT contrast agent in vivo. Reporting in Nanotechnology, researchers have designed a Bi2S3-PF127 probe that not only has good CT imaging performance but is also safe and biocompatible.
(a) TEM image of Bi2S3-PF127. (b) Phantom images of Bi2S3-PF127. (c) CT sectional views of a mouse after injecting Bi2S3-PF127 nanoparticles into the tail vein
Pluronic F127 (PF127) is an ABA-type triblock copolymer that presents high biocompatibility and an ideal surface modification of materials. It is highly safe in vivo and has been approved for use in intravenous drugs by the US Food and Drug Adminstration (FDA).
Transformation of the probe
Researchers from Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology in China transformed Bi2S3-PF127 nanoparticles from Bi2S3-OAm by stirring in the PF127 solution. Fourier transform infrared spectroscopy (FT-IR) spectra, transmission electron microscopy (TEM) and physical stability were used to characterize the modification.
Biocompatible and safe
The authors demonstrate in vitro and in vivo CT imaging using the Bi2S3-PF127 probe through phantom imaging, cell imaging and mouse imaging by the self-image system, which all show a good contrast effect. They then study the biological distribution of Bi by inductively coupled plasma atomic emission spectroscopy (ICP-AES). This confirms that most of the nanoparticles are cleaned out after injection by 48 hours and that the Bi2S3-PF127 probe has a long circulation. Hematoxylin and eosin stains, biochemical analysis and blood analysis confirm that the probe has good biocompatibility and safety.
More information can be found in the journal Nanotechnology 25 295103.
About the author
Jun Chen is a PhD candidate in the research group of Yuan-Di Zhao at Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China. During her PhD study, her research focuses on synthesis, characterization and application of functional nanoparticles, for example bismuth sulfide, quantum dots and multifunction probe, in targeted CT/fluorescence dual-mode imaging.