Imaging Characteristics of USPIO Nanoparticles (

Xiaohong Ma,Longbin Hu,Shichao Feng,Xinming Zhao,Shuang Wang,Chunwu Zhou,Zhiyuan Wu,Siyun Liu,Shaofeng Duan,Zhongwei Chen

doi:10.1155/2019/3687537

Abstract

Iron nanoparticles have an increasingly more and more important role in MR molecular imaging due to their novel magnetic and surface chemical properties. They provide new possibilities for noninvasive diagnosis and treatment monitoring, especially for tissues that are rich in macrophages. The smaller size and prolongation of the plasma half-life change the in vivo fate of ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles captured by liver in reticuloendothelial system (RES) or mononuclear phagocytic system (MPS). However, there is still a lack of MR imaging studies on the liver assessing USPIO nanoparticles <5 nm in size to reflect its absorption and clearance properties. In this study, we used MRI to study the in vitro phantom and in vivo rat liver imaging characteristics of USPIO nanoparticles (<5 nm). The results showed that USPIO nanoparticles (<5 nm) could potentially reduce longitudinal and transverse relaxation times and showed similar T1 relaxation rates compared with commercial gadolinium chelates. In addition, USPIO nanoparticles (<5 nm) in vivo demonstrated both positive (T1) and negative (T2) liver contrast enhancement in healthy rats' liver. Furthermore, USPIO nanoparticles showed relatively good in vitro biocompatibility and fast clearance (within 45.17 minutes after intravenous injection) in the normal liver. Taken together, these data might inspire a new personalized and precise diagnostic tool and stimulate new applications for specific targeted molecular probes.

Highlights

Magnetic resonance imaging (MRI) is widely used in clinical practice due to its advantages of nonionizing radiation, multisequencing, and better soft tissue contrast. e latest results of molecular imaging using Magnetic resonance region of interest (ROI) (MR) scanning provide new methods for noninvasive detection or tracking of such conditions as hepatocellular carcinoma [1, 2], atherosclerotic plaque [3], collateral circulation in acute ischemic stroke [4], and glioma gene therapy [5]
In Vitro Biocompatibility of 5 nm ultrasmall superparamagnetic iron oxide (USPIO) Nanoparticles by MTT and Prussian Blue Staining Assay. e effect of 5 nm USPIO nanoparticles on the cell viability of rat normal hepatic cells BRL-3A was determined and quantified by MTT assay as shown in Figure 3(a). e 5 nm USPIO nanoparticles significantly reduced the cell viability to 94.17% and 84.9% at concentration of 200 μg·Fe/mL for 24 hours incubation, while the cell viability maintained more than 95% for 24 h incubation at lower iron concentrations less than 200 μg·Fe/mL or shorter incubation time (12 hours) at highest concentration of 400 μg·Fe/mL
Smaller USPIO nanoparticles have been implicated in the new routes for applications especially due to their beneficial safety profile, such as in nephrogenic sclerosis and for renal insufficient patients compared with gadolinium chelates

Summary

Introduction

Magnetic resonance imaging (MRI) is widely used in clinical practice due to its advantages of nonionizing radiation, multisequencing, and better soft tissue contrast. e latest results of molecular imaging using MR scanning provide new methods for noninvasive detection or tracking of such conditions as hepatocellular carcinoma [1, 2], atherosclerotic plaque [3], collateral circulation in acute ischemic stroke [4], and glioma gene therapy [5]. E latest results of molecular imaging using MR scanning provide new methods for noninvasive detection or tracking of such conditions as hepatocellular carcinoma [1, 2], atherosclerotic plaque [3], collateral circulation in acute ischemic stroke [4], and glioma gene therapy [5]. It is emerging as a kind of functional MR probe system, for example, stimuli-responsive MRI-monitored drug delivery system, including pH-responsive [6,7,8] or thermo-responsive [9] ones. The low cost, biological safety, and exible surface modi cations promote wide utilization of SPIO nanoparticles as contrast agents or as a platform for construction of speci c targeting probes in MRI research

Methods

Results

Discussion

Conclusion