Facile synthesis of hyaluronic acid-modified Fe3O4/Au composite nanoparticles for targeted dual mode MR/CT imaging of tumors

Abstract

A facile co-precipitation approach for synthesizing hyaluronic acid (HA)-modified Fe₃O₄/Au composite nanoparticles (CNPs) for targeted dual mode tumor magnetic resonance (MR) and computed tomography (CT) imaging is reported. In this work, polyethyleneimine (PEI) was employed as a stabilizer to form gold NPs (PEI–Au NPs). In the presence of the PEI–Au NPs, controlled co-precipitation of Fe(II) and Fe(III) salts was performed, leading to the formation of the Fe₃O₄/Au–PEI CNPs, which were further modified with hyaluronic acid (HA). We show that the formed Fe₃O₄/Au–PEI–HA CNPs are colloidally stable, hemocompatible and cytocompatible in a given concentration range, and have a high affinity to target CD44 receptor-overexpressing cancer cells. Due to the presence of Fe₃O₄ and Au components, the formed Fe₃O₄/Au–PEI–HA CNPs display a high r₂ relaxivity (264.16 mM⁻¹ s⁻¹) and good X-ray attenuation property, rendering them with an ability to be used as a nanoprobe for targeted dual mode MR/CT imaging of CD44 receptor-overexpressing cancer cells in vitro and a xenografted tumor model in vivo. The Fe₃O₄/Au–PEI–HA CNPs developed via this facile approach may hold great promise to be used as a unique platform for precision imaging of CD44 receptor-overexpressing tumors.