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

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 r(2) 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.