New MRI Tool Introduced for Cancer Diagnosis and Therapy

A superparamagnetic ferritin compound improves the accuracy of diagnosing malignant cells and provides additional opportunities for cancer treatment, claims a new study.

Researchers at Helmholtz Zentrum München (Munich, Germany), the Russian National University of Science and Technology (NUST-MISiS; Moscow, Russia), and other institutions have synthesized a novel magnetoferritin, consisting of an endogenous human protein (ferritin) and a magnetic nucleus, which has been optimized for cellular uptake and ensuing trafficking to lysosomes. It can thus serve as a hypoallergenic contrast agent for optoacoustic imaging, and allow for selective photoablation of cells overexpressing the ferritin receptors.

According to the researchers, the genetically controlled uptake of the biomagnetic nanoparticles also strongly enhances third‐harmonic generation, due to the change of the refractive index caused by the magnetite–protein interface of ferritins entrapped in lysosomes. Selective uptake of magnetoferritin also enables detection of receptor‐expressing cells by magnetic resonance imaging (MRI), as well as efficient magnetic cell sorting and manipulation. A substantial increase in the blocking temperature of lysosomally entrapped magnetoferritin was also observed, which could allow for specific ablation of genetically defined cell populations by magnetic hyperthermia. The study was published in the May 2018 issue of Advanced Functional Materials.

“Spreading with the blood flow, magnetoferritin will be captured by the targeted tumor cells; as has been shown in a large number of studies, these cells actively capture transferrin, the protein responsible for the transport of iron in the blood,” said study co-author Professor Ulf Wiedwald, PhD, of the NUST-MISiS biomedical nanomaterials laboratory. “The receptors are capable of capturing the magnetoferritin as well. Once they get into the lysosomes of targeted cells, the magnetoferritin will further enhance the contrast signal.”

Transferrins are iron-binding blood plasma glycoproteins that control the level of free iron in biological fluids. Although the iron bound to transferrin is less than 0.1% of total body iron, it forms the most vital iron pool with the highest rate of turnover (25 mg/d). Transferrin also plays a key role in areas where erythropoiesis and active cell division occur, delivering iron absorption centers in the duodenum and white blood cell macrophages to all tissues.

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Helmholtz Zentrum München
Russian National University of Science and Technology