Rational Constructed Ultra-Small Iron Oxide Nanoprobes Manifesting High Performance for T1-Weighted Magnetic Resonance Imaging of Glioblastoma

Abstract

Precise diagnosis and monitoring of cancer depend on the development of advanced technologies for in vivo imaging. Owing to the merits of outstanding spatial resolution and excellent soft-tissue contrast, the application of magnetic resonance imaging (MRI) in biomedicine is of great importance. Herein, Angiopep-2 (ANG), which can simultaneously help to cross the blood-brain barrier and target the glioblastoma cells, was rationally combined with the 3.3 nm-sized ultra-small iron oxide (Fe₃O₄) to construct high-performance MRI nanoprobes (Fe₃O₄-ANG NPs) for glioblastoma diagnosis. The in vitro experiments show that the resultant Fe₃O₄-ANG NPs not only exhibit favorable relaxation properties and colloidal stability, but also have low toxicity and high specificity to glioblastoma cells, which provide critical prerequisites for the in vivo tumor imaging. Furthermore, in vivo imaging results show that the Fe₃O₄-ANG NPs exhibit good targeting ability toward subcutaneous and orthotopic glioblastoma model, manifesting an obvious contrast enhancement effect on the <i>T</i>₁-weighted MR image, which demonstrates promising potential in clinical application.