New Class of Efficient T2 Magnetic Resonance Imaging Contrast Agent: Carbon-Coated Paramagnetic Dysprosium Oxide Nanoparticles.

Huan Yue,Gang Ho Lee,Hyunsil Cha,Mohammad Yaseen Ahmad,Ji Ae Park,Son Long Ho,Kwon Seok Chae,Yongmin Chang,Adibehalsadat Ghazanfari,Shuwen Liu,Tirusew Tegafaw,Shanti Marasini,Soyeon Kim

doi:10.3390/ph13100312

Abstract

Nanoparticles are considered potential candidates for a new class of magnetic resonance imaging (MRI) contrast agents. Negative MRI contrast agents require high magnetic moments. However, if nanoparticles can exclusively induce transverse water proton spin relaxation with negligible induction of longitudinal water proton spin relaxation, they may provide negative contrast MR images despite having low magnetic moments, thus acting as an efficient T2 MRI contrast agent. In this study, carbon-coated paramagnetic dysprosium oxide (DYO@C) nanoparticles (core = DYO = DyxOy; shell = carbon) were synthesized to explore their potential as an efficient T2 MRI contrast agent at 3.0 T MR field. Since the core DYO nanoparticles have an appreciable (but not high) magnetic moment that arises from fast 4f-electrons of Dy(III) (6H15/2), the DYO@C nanoparticles exhibited an appreciable transverse water proton spin relaxivity (r2) with a negligible longitudinal water proton spin relaxivity (r1). Consequently, they acted as a very efficient T2 MRI contrast agent, as proven from negative contrast enhancements seen in the in vivo T2 MR images.

Highlights

Nanotechnology and nanomaterials may provide a breakthrough in future medicine science [1,2]
Nanoparticles have tremendous potential for application in various medical fields owing to their unique and excellent properties, which are better than those of atomic, molecular, and bulk materials [3,4,5,6]. They may be applied as advanced negative (T2) magnetic resonance imaging (MRI) contrast agents to elevate negative contrast differentials between normal and abnormal tissues [7,8,9]; this effect cannot be obtained using molecular agents because molecules do not have sufficient magnetic moments
New ultrasmall nanoparticles that can be used for various organs and that possess renal excretion ability should be developed as a new class of T2 MRI contrast agents

Summary

Introduction

Nanotechnology and nanomaterials may provide a breakthrough in future medicine science [1,2]. Nanoparticles have tremendous potential for application in various medical fields owing to their unique and excellent properties, which are better than those of atomic, molecular, and bulk materials [3,4,5,6] They may be applied as advanced negative (T2) magnetic resonance imaging (MRI) contrast agents to elevate negative contrast differentials between normal and abnormal tissues [7,8,9]; this effect cannot be obtained using molecular agents because molecules do not have sufficient magnetic moments. Resovist, a commercial SPIO-based contrast agent, is coated with dextran and has multiple SPIOs with a diameter of 4.2 nm at the core It has a hydrodynamic diameter of 60 nm and is used for liver imaging [15]. New ultrasmall nanoparticles that can be used for various organs and that possess renal excretion ability should be developed as a new class of T2 MRI contrast agents

Methods

Results

Conclusion