Design of FeBi nanoparticles for imaging applications

Area of Science:

• Nanotechnology
• Materials Science
• Biomedical Imaging

Background:

• Medical imaging relies on contrast agents, with nanoparticles (NPs) enhancing in vivo imaging contrast and targeting.
• The development of multifunctional dual-contrast agents on a single NP is a significant trend in medical imaging.
• Iron (Fe) is established for MRI contrast, while Bismuth (Bi) offers high X-ray attenuation for CT imaging.

Purpose of the Study:

• To develop novel iron-bismuth (FeBi) nanoparticles as dual-modal contrast agents for MRI and CT imaging.
• To investigate the synthesis and characterization of FeBi NPs with varying sizes and surface properties.
• To explore the functionalization of FeBi NPs for aqueous applications, crucial for in vivo use.

Main Methods:

• Organometallic approaches were used to synthesize two sets of FeBi nanoparticles, approximately 150 nm and 14 nm in diameter.
• Characterization confirmed spherical NPs with distinct Fe and Bi domains, Fe-enriched surfaces, and hydrophobic coatings (amine ligands or amine/hydrochloride mixtures).
• Surface ligand exchange was attempted to create water-soluble NPs, with successful functionalization achieved for the larger NPs using glycoPEG ligands.

Main Results:

• Spherical FeBi nanoparticles of ~150 nm and ~14 nm were successfully synthesized.
• The larger NPs exhibited a more labile surface coating, enabling successful functionalization with water-soluble glycoPEG ligands.
• Colloidal aqueous solutions of FeBi NPs were obtained, demonstrating potential for biomedical applications.

Conclusions:

• FeBi nanoparticles represent a promising new class of nanomaterials for dual MRI and CT imaging.
• The size-dependent surface ligand lability influences the ability to create water-soluble contrast agents.
• The developed FeBi NPs, particularly the larger, functionalized variants, hold potential as cost-effective and efficient imaging agents.