Hepatocellular lesions with increased iron uptake on superparamagnetic iron oxide-enhanced magnetic resonance imaging in cirrhosis or chronic hepatitis: comparison of four magnetic resonance sequences for lesion conspicuity

Magnetic Relaxation Switching Assay Using IFNα-2b-Conjugated Superparamagnetic Nanoparticles for Anti-Interferon Antibody Detection

Type I interferons, particularly IFNα-2b, play essential roles in eliciting adaptive and innate immune responses, being implicated in the pathogenesis of various diseases, including cancer, and autoimmune and infectious diseases. Therefore, the development of a highly sensitive platform for analysis of either IFNα-2b or anti-IFNα-2b antibodies is of high importance to improve the diagnosis of various pathologies associated with the IFNα-2b disbalance. For evaluation of the anti-IFNα-2b antibody level, we have synthesized superparamagnetic iron oxide nanoparticles (SPIONs) coupled with the recombinant human IFNα-2b protein (SPIONs@IFNα-2b). Employing a magnetic relaxation switching assay (MRSw)-based nanosensor, we detected picomolar concentrations (0.36 pg/mL) of anti-INFα-2b antibodies. The high sensitivity of the real-time antibodies' detection was ensured by the specificity of immune responses and the maintenance of resonance conditions for water spins by choosing a high-frequency filling of short radio-frequency pulses of the generator. The formation of a complex of the SPIONs@IFNα-2b nanoparticles with the anti-INFα-2b antibodies led to a cascade process of the formation of nanoparticle clusters, which was further enhanced by exposure to a strong (7.1 T) homogenous magnetic field. Obtained magnetic conjugates exhibited high negative MR contrast-enhancing properties (as shown by NMR studies) that were also preserved when particles were administered in vivo. Thus, we observed a 1.2-fold decrease of the T2 relaxation time in the liver following administration of magnetic conjugates as compared to the control. In conclusion, the developed MRSw assay based on SPIONs@IFNα-2b nanoparticles represents an alternative immunological probe for the estimation of anti-IFNα-2b antibodies that could be further employed in clinical studies.

The long-lasting effect of ferumoxytol on abdominal magnetic resonance imaging

Ferumoxytol is a parenteral iron therapy that the Food and Drug Administration recently approved for the treatment of iron-deficiency anemia. The form of the iron, ultrasmall superparamagnetic iron oxide nanoparticles, causes T1, T2, and T2* shortening on magnetic resonance imaging, which can mimic hemosiderosis. We report such a case, with laboratory findings that demonstrate normal iron stores, and discuss the potential implications.

Evaluation of the uptake function of liver in rats with obstructive jaundice before and after relief from obstruction by superparamagnetic iron oxide-enhanced magnetic resonance imaging

The aim of this study was to investigate the changes in the uptake function of the liver in rats with obstructive jaundice prior to and following relief from obstructive jaundice, and to investigate whether superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance imaging (MRI) could be used to assess liver uptake function. In total, 40 male Sprague Dawley rats were randomly assigned into four groups: Obstructive jaundice, internal drainage, external drainage and sham surgery. The common bile ducts in the obstructive jaundice group were ligated. Internal drainage (ID) and external drainage (ED) groups were ligated, followed by internal drainage or external drainage, respectively. The T2 and T2* values of the liver parenchyma were measured. Liver sections were stained with Perls' Prussian blue, and hematoxylin and eosin. The number of SPIO-nanoparticle clusters was counted manually using a microscope. Total bilirubin of the blood was measured. Results showed that the T2 and T2* values and total bilirubin of the obstructive jaundice group were significantly higher compared to the other three groups. The number of SPIO-nanoparticle clusters in the obstructive jaundice group was significantly lower compared to the other three groups. In conclusion, obstructive jaundice suppresses liver uptake function in rats, which may be reversed by internal and external biliary drainage. However, no significant difference was found between the therapeutic effect of ID and ED on liver uptake function. Thus, SPIO-enhanced MRI may be used to evaluate the uptake function of the liver.