In Vivo HER2-Targeted Magnetic Resonance Tumor Imaging Using Iron Oxide Nanoparticles Conjugated with Anti-HER2 Fragment Antibody.

Abstract

The feasibility of iron oxide nanoparticles (IONPs) conjugated with anti-epidermal growth factor receptor 2 (HER2) single-chain antibody (scFv-IONPs) as novel HER2-targeted magnetic resonance (MR) contrast agents was investigated. The scFv-IONPs were prepared and identified. For in vitro MRI, NCI-N87 (HER2 high expression) and SUIT2 (low expression) cells were incubated with scFv-IONPs. For in vivo MRI, NCI-N87 and SUIT2 tumor-bearing mice were intravenously injected with scFv-IONPs and imaged before and 24h post-injection. The scFv-IONPs demonstrated high transverse relaxivity (296.3s-1mM-1) and affinity toward HER2 (KD = 11.7nM). In the in vitro MRI, NCI-N87 cells treated with scFv-IONPs exhibited significant MR signal reduction (44.6%) than SUIT2 cells (6.8%). In the in vivo MRI, decrease of MR signals in NCI-N87 tumors (19.3%) was more notable than that in SUIT2 tumors (6.2%). The scFv-IONPs enabled HER2-specific tumor MR imaging, suggesting the potential of scFv-IONPs as a robust HER2-targeted MR contrast agent.