Sequential growth of CaF₂:Yb,Er@CaF₂:Gd nanoparticles for efficient magnetic resonance angiography and tumor diagnosis

Abstract

It is a significant challenge to develop nanoscale magnetic resonance imaging (MRI) contrast agents with high performance of relaxation. In this work, Gd-doped CaF-based core-shell nanoparticles (CaF:Yb,Er@CaF:Gd) of sub-10 nm size were controllably synthesized by a facile sequential growth method. The as-prepared hydrophilic CaF:Yb,Er@CaF:Gd nanoparticles modified using PEG-PAA di-block copolymer benefited from the presence of Gd only in the outer CaF layer of the nanoparticles, which exhibited r as high as 21.86 mM s under 3.0 T, seven times as high as that of commercially used gadopentetate dimeglumine (Gd-DTPA). Low cytotoxicity, no hemolysis phenomenon and no potential gadolinium ion leakage phenomenon of the hydrophilic CaF:Yb,Er@CaF:Gd nanoparticles have been observed and confirmed. Clear vascular details can be observed in magnetic resonance angiography and obvious MR signal of 4T1 tumor area could be significantly improved by intravenous injection of the hydrophilic CaF:Yb,Er@CaF:Gd nanoparticles at a low dosage in mice. A series of in vivo biological safety evaluations confirmed the good biocompatibility of the hydrophilic CaF:Yb,Er@CaF:Gd nanoparticles, which might be employed in clinical blood pool imaging and tumor diagnosis as a safe and efficient MRI probe.

Sequential Growth of High Quality Sub-10 nm Core–Shell Nanocrystals: Understanding the Nucleation and Growth Process Using Dynamic Light Scattering

“…Nanostructures with ultra-small size (sub-10 nm) possess high specific surface area, tunable photochemical and electrochemical performance, − and minimal biosafety risk, − which are of great importance for practical applications in catalysis, − energy conversion and storage, − and biomedicine. − Additionally, core–shell nanostructures exhibit improved and tunable physical and chemical properties for electrons, optics, and magnetism. − In the past two decades, much effort has been devoted to develop various synthetic strategies for preparing many core–shell nanostructures with sub-10 nm size. Especially, the template strategy − and epitaxial growth method − have been proposed to fabricate monodisperse sub-10 nm nanocrystals.…”

Medical imaging modalities using nanoprobes for cancer diagnosis: A literature review on recent findings

“…synthesized and applied hydrophilic CaF 2 :Yb, Er@CaF 2 :Gd nanoparticles modified using PEG-PAA di-block copolymer benefited from the presence of Gd only in the outer CaF 2 layer of the nanoparticles Gd 3+ -doped CaF 2 -based core-shell nanoparticles for efficient magnetic resonance angiography and tumor diagnosis. [38]…”

A literature review on multimodality molecular imaging nanoprobes for cancer detection

“…They have targeted PEG-MnO NPs with amino group modified AS1411 and indicated the promising potential of PEG-MnO NPs as T 1 MRI contrast agent for the molecular MR imaging of 786-0 renal carcinoma. Hydrophilic CaF 2 :Yb,Er@CaF 2 :Gd nanoparticles modified using polyethylene glycol-polyamidoamine (PEG-PAA) diblock copolymer benefited from the presence of Gd only in the outer CaF 2 layer of the nanoparticles for efficient MR angiography (MRA) and cancer detection which was developed by Liu K et al [88]. In another work, NaErF 4 @NaGdF 4 (Er@Gd) nanoparticle evaluated by Liyi Ma et al [89] for MRI and short wave infra-red (SWIR) imaging.…”