Lactoferrin-conjugated superparamagnetic iron oxide nanoparticles as a specific MRI contrast agent for detection of brain glioma in vivo.

A specific contrast agent for magnetic resonance imaging (MRI) is crucial to brain tumor patients for the surgical operation or the postoperative radiology. This study explored lactoferrin-conjugated superparamagnetic iron oxide nanoparticles (Lf-SPIONs) as an MRI contrast agent for the detection of brain gliomas in vivo. The hydrodynamic diameter of about 75 nm, saturation magnetization of 51 emu/g Fe and T(2) relaxivity of 75.6 mM(-1)S(-1) of the Lf-SPIONs suggested its applicability for MRI. Using a rat model of C6 glioma, Lf-SPIONs provided a better picture or more sensitivity to depict brain glioma on MR images than that of SPIONs. Significantly enhanced T(2)-weighted images of brain glioma were documented in vivo with Lf-SPIONs until 48 h after injection. Moreover, Lf-SPIONs were clearly observed around vascular region of the tumor slices after 48 h. High level expression of Lf receptors was confirmed in brain tumor tissues by RT-PCR and Western Blot compared to normal brain tissues. These findings suggested that Lf-SPIONs could be potentially employed as a sensitive and specific MRI contrast agent in the diagnosis of brain glioma.