Scientists from Nanoprobes, Inc. claim that magnetic nanoparticles can cure cancer in just one treatment. Their findings are published in The International Journal of Nanomedicine.
The team, led by Dr. James F. Hainfeld, claims that an injection containing the nanoparticles followed by 3 minutes in a magnetic field "completely cured" test animals of cancer.
The idea is surprisingly simple. When you put an iron particle inside an alternating magnetic field, it spins back and forth, generating significant heat. So, if you can deliver enough iron particles to a tumor, you can actually "cook" the cancer.
However, translating the theory into science proved slightly more tricky.
One of the main obstacles the scientists faced was that the amount of iron needed for cancer therapy was toxic to the body. And while scientists had tried to overcome this by injecting the iron directly into the tumor, they found that any areas they missed would inevitably grow back.
Dr. Hainfeld, one of the pioneers of nanotechnogy, decided to look at the problem from a different angle. Instead of looking at a more precise way of injecting iron, he decided to alter the actual iron particle itself.
Together with his colleague, Hui Huang, the scientists spent 6 years engineering a nanoparticle with an iron core and a biocompatible shell. This could be injected into the bloodstream without adverse effects.
'Enhanced permeability and retention effect'
Tumors need to grow quickly and to achieve this, scientists believe they stimulate the production of blood vessels. One of the side effects of the accelerated production is that the new vessels tend to be leaky - and they lack effective lymphatic drainage.
This phenomenon - known as the "enhanced permeability and retention effect" - is one that nanotechnology exploits. The leaky vessels allow particles to accumulate in the tumor, while the lack of adequate drainage means they remain there for longer than in healthy cells.
Knowing this, Dr. Hainfeld sized the iron particles specifically to leak into the tumors. Another advantage of this treatment is that the nanoparticles will find cancerous cells anywhere in the body, even if they have metastasized - or spread to other organs in the body.
And, crucially, since the magnetic fields pass through the entire human body, the nanoparticles will also heat deep tumors that were previously inaccessible.
When the nanoparticle was finally ready for testing, its iron core was encased in a biocompatible shell that was large enough to allow the core to spin but still left enough space to slip through the leaky blood vessels. It also had long polymer strands to keep it out of the liver.
The scientists then injected the nanoparticles into the bloodstream of mice afflicted with cancer. The animals showed no adverse reaction to the injections, showing that the scientists had overcome the problem with iron's toxicity.
The scientists note that the particles pooled in the tumors - with approximately 16 times the concentration of the surrounding healthy tissue.
The final test of the experiment was to expose the animals to a rapidly alternating magnetic field. Using an infrared camera to measure the temperature inside the tumors, they saw these rise high enough to "melt" the cancer, while leaving surrounding tissue cool and unharmed.
Success rate between 78% and 90% in mice
After a 3-minute treatment, the scientists say the tumors were completely eradicated, "with a precision finer than a surgeon's knife."
Another plus of the treatment is that the "melted" tumors' neutralized remains are simply absorbed by the body, while the nanoparticles break down slowly over time, allowing the body to process the surplus iron harmlessly.
Dr. Hainfeld and Huang claim a success rate of 78-90% in mice.
Working in collaboration with Dr. Henry Smilowitz of the University of Connecticut Health center, the pair have also demonstrated excellent results for treating in vivo brain cancer.
Crossing the blood-brain barrier presents its own problems, but they were able to demonstrate a "razor-sharp concentration ratio at the edge of the brain tumor." Crucially, this precision would save healthy brain matter when the area was magnetically heated.
Dr. Hainfeld and Huang's work has been recognized by the National Institutes of Health, and they are currently conducting more lab tests in preparation for FDA approval.