Shake it up every once in a while…

Using tiny vibrating magnets to destroy cancer cells

I am developing a targeted therapy for brain cancer, and while biochemists have used various cocktails of drugs to destroy cancerous cells, the cells have proved frustratingly resilient to date. The present treatment for brain cancer often involves a combination of surgery, radiotherapy, and chemotherapy, and yet sadly the mortality rate with this cancer remains high. The most common brain cancer, glioblastoma multiforme, is notoriously aggressive. And it’s also really, really hard to reach the brain with drugs, since it’s separated from circulating blood by the blood-brain barrier, making treatment incredibly challenging.  

As a physicist, I’m in over my head in the fields of biochemistry and drug development, so I invoke a different approach to attacking these cancerous cells. Interestingly, cells are responsive to mechanical stimuli, and poking, prodding, and vibrating a cell can lead to quite profound effects on cell functions. Dial up the mechanical stimulation enough, and you can even cause a shutdown of cellular function and destruction of the cell. We can potentially use this to destroy tumour cells, but how to exert forces on cells in a place you can’t necessarily reach, and how do you do it at a time of your choosing?

Since iron filings feel the effect of a magnet from quite a distance, and move in response to the motion of the magnet, magnetism is a pretty effective way of exerting force at a distance. I build magnetic particles that respond in a specific manner to magnetic fields, but they are discs that are one micron in diameter, and only a few hundred nanometres thick. A single one of these magnetic discs looks rather like a pancake, except shrunk down a hundred thousand times! This means that I can inject them into a tumour and make them either infiltrate or attach to the cancerous cells. If I then apply a rotating magnetic field to the tumour area, the injected particles rotate and oscillate in response to the field. This mechanical stimulus is enough to seriously damage and even kill cells, often by destroying the integrity of the cell membrane.

With this work, I’m using an unconventional approach to damage and destroy cancerous tissue, and initial in-vitro results have been quite positive, where 90% of the cancer cells were killed after just a few minutes of applying the rotating magnetic field. I’m looking forward to the further testing of this therapy in-vivo, and to tackling the new challenges that this will bring!

Tarun Vemulkar

NanoDTC PhD Student Cohort 2012

Thin Film Magnetism Group, PhysicsBiointerface Group, Engineering

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