Facile Synthesis of Holmium-Based Nanoparticles as a CT and MRI Dual-Modal Imaging for Cancer Diagnosis

Abstract

The rapid development of medical imaging has boosted the abilities of modern medicine. As single modality imaging limits complex cancer diagnostics, dual-modal imaging has come into the spotlight in clinical settings. The rare earth element Holmium (Ho) has intrinsic paramagnetism and great X-ray attenuation due to its high atomic number. These features endow Ho with good potential to be a nanoprobe in combined x-ray computed tomography (CT) and T2-weighted magnetic resonance imaging (MRI). Herein, we present a facile strategy for preparing HoF3 nanoparticles (HoF3 NPs) with modification by PEG 4000. The functional PEG-HoF3 NPs have good water solubility, low cytotoxicity, and biocompatibility as a dual-modal contrast agent. Currently, there is limited systematic and intensive investigation of Ho-based nanomaterials for dual-modal imaging. Our PEG-HoF3 NPs provide a new direction to realize in vitro and vivo CT/MRI imaging, as well as validation of Ho-based nanomaterials will verify their potential for biomedical applications.

Magnetic Nanoparticle-Based High-Performance Positive and Negative Magnetic Resonance Imaging Contrast Agents

“…Recently, Zhang et al conducted a study on PEG-HoF 3 NPs (PEG Mw = 4000 amu and mean particle diameter = 38 nm) as a T 2 MRI contrast agent for cancer diagnosis [ 95 ]. The NPs had an r 2 value of 117.51 mM −1 s −1 at 7 T, and 24 h after intravenous injection, negative (or darker) contrasts in T 2 MR images in the tumors of tumor-bearing mice were observed because of the accumulation of NPs in the tumor, demonstrating the potential of the NPs as a T 2 MRI contrast agent.…”

Methods for Radiolabeling Nanoparticles (Part 3): Therapeutic Use

“…These features make 166 Ho an ideal isotope for theragnostic purposes. Furthermore, 166 Ho is a paramagnetic and electron-dense element that can be used for X-ray computed tomography (CT) and magnetic resonance imaging [ 119 , 120 , 121 ].…”

Heavy Metal-Based Nanoparticles as High-Performance X-ray Computed Tomography Contrast Agents

“…Similar to Dy, Ho possesses a high X-ray attenuation coefficient [4]; thus, Ho-based NPs can be used as CT contrast agents. In addition, the high magnetic moment of Ho Zhang et al synthesized PEG-modified HoF 3 NPs using a one-pot solvothermal technique [38]. The PEG-HoF 3 NPs exhibited size uniformity and exhibited excellent dispersibility in an aqueous solution due to the PEG coating (d = 38 nm and HD = ~100 nm) (Figure 8a).…”

“…Zhang et al synthesized PEG-modified HoF3 NPs using a one-pot solvothermal technique [38]. The PEG-HoF3 NPs exhibited size uniformity and exhibited excellent dispersibility in an aqueous solution due to the PEG coating (d = 38 nm and HD = ~100 nm) (Figure 8a).…”

“…Various heavy metal-based NPs have been investigated as potential CT contrast agents in pure metallic or chemical forms, including palladium (Pd, Z = 46) [24], silver (Ag, Z = 47) [25][26][27][28], cerium (Ce, Z = 58) [29,30], gadolinium (Gd, Z = 64) [31][32][33][34][35], dysprosium (Dy, Z = 66) [32,36,37], holmium (Ho, Z = 67) [37][38][39][40], ytterbium (Yb, Z = 70) [32,[41][42][43][44][45][46], tantalum (Ta, Z = 73) [32,[47][48][49][50], tungsten (W, Z = 74) [51][52][53][54][55], platinum (Pt, Z = 78) [56][57][58][59][60][61][62][63], gold (Au, Z = 79) [64][65][66][67]…”