Tiny Magnets Find Brain Cancer Cells

Be aware! A persistent head-ache today may be a serious brain tumour tomorrow

Nupur Fangaria
Loka Biosciences Pvt. Ltd.

A 40-year-old man has been suffering from a persistent headache with a feeling of nausea for a month. He finally visits the doctor who suggests he undergo an MRI scan. However, the MRI scan looks normal and a puzzled man is sent home with a dose of Aspirin. Within a week, he suffers from a seizure and is rushed back to the hospital. The doctor, now suspecting brain cancer, prescribes a PET scan. The man’s brain lights up in the scan like a Christmas tree, sucking away all the cheer and joy from his life. The cancer has spread to each lit-up point of his brain. This is the story of almost every person who is suffering from the vicious brain cancer known as “Glioblastoma”.

Glioblastomas are the most common type of brain cancer. However, the recurrence of these glioblastomas does not ease the difficulty in their detection. In India, recent surveys have shown that 40,000-50,000 instances of brain cancer are recorded each year, 20 per cent being children with 24,000 individuals dying annually. The major reason for the alarming number of deaths is the late diagnosis of brain cancer. The first line of diagnosis of brain cancer is to undergo MRI (Magnetic Resonance Imaging) scans. MRI is an imaging technology that can take internal pictures of the body using magnetic field vibrations generated by protons. Although this process is effective in creating clear, defined pictures of internal organs of the body such as the brain, however, it is ineffective in distinguishing a normal brain and a cancer-riddled brain since the structure of both are almost identical. Hence, there is a need to create a better method to diagnose brain cancer.

Scientists have newly developed a revolutionized way to detect gliomas, or brain tumors, using magnetic nanoparticles, which are tiny iron oxide particles of diameter 0.0000014 centimeters. These are so tiny that they can easily pass through the blood-brain barrier, which only allows the passage of particles of size less than 0.0000025 centimetres, and hence enter into the brain.

These magnetic nanoparticles are covered with a protein called “lactoferrin” which specifically sticks to the cancer cells since the surface of the cancer cells is covered with “lactoferrin receptors”. These magnetic nanoparticles stuck to the cancer cells are then detected using a technique called “Magnetic Particle Imaging (MPI)”. MPI uses a tracker-based technique and detects in real-time, the movement of the magnetic nanoparticles through the brain and their accumulation in cancer cells. MPI uses alternating magnetic fields to trace the magnetization response of the nanoparticles and creates high-resolution 3D images. The magnetization of the iron oxide nanoparticles used in MPI imaging is 10000000 times the magnetization of protons which are used in MRI imaging giving a much clearer image of the brain, specifically highlighting the area containing cancer. MPI has proven to be a strong candidate for targeted imaging of brain cancer since it is a highly sensitive technique with no background interference and high contrast. Furthermore, the lactoferrin-coated iron oxide nanoparticles used in this technique for brain cancer detection are highly biocompatible with little to no side effects.

Although a highly effective detection technique has now been developed, however, we are still a long way off from the treatment of brain cancer. Due to the presence of the blood-brain barrier, a very limited number of administered drugs actually reach the brain and are available for treating the cancer in the brain. Furthermore, these anti-cancer drugs are very toxic and have many off-targets and thus lead to various side effects. Hence, a more targeted approach to treat brain cancer is required such as a nanoparticle-based delivery of the drug to minimize the off-targets and provide a more effective form of treatment. Early signs of the onset of the disease condition should be screened with effective techniques without ignoring the early symptoms of it.