Lectin-Conjugated Fe₂O₃@Au Core@Shell Nanoparticles as Dual Mode Contrast Agents for <i>in Vivo</i> Detection of Tumor

Abstract

Here, we report the covalent conjugation of lectin on Fe₂O₃@Au core@shell nanoparticle (lectin–Fe₂O₃@Au NP) for <i>T</i>₂-weighted magnetic resonance (MR) and X-ray computed tomography (CT) dual-modality imaging. The lectin–Fe₂O₃@Au NPs are prepared by coupling lectins to the Fe₂O₃@Au NP surfaces through bifunctional PEG NHS ester disulfide (NHS-PEG-S-S-PEG-NHS) linkers. After the nonspecific adsorption sites on the nanoparticle surface are blocked by thiolated PEG (PEG-SH), the lectin–Fe₂O₃@Au NPs exhibit excellent stability in biological medium and inappreciable cytotoxicity. A series of <i>in vitro</i> and <i>in vivo</i> experiments were then carried out for evaluating the capabilities of three selected lectin (ConA, RCA and WGA)-Fe₂O₃@Au NPs. The results revealed that the lectin–Fe₂O₃@Au NPs had a capacity not only for dual mode MR and CT imaging <i>in vitro</i> but also for MR and CT imaging of colorectal cancer <i>in vivo</i>. The experimental results also suggest that lectin could be used as tumor targeting ligand for synthesizing nanoparticle-based contrast agents