In 1966, scientists made a huge breakthrough in nanomedicine. They found they could miniaturise a submarine and its crew and inject it into a patient's bloodstream. The sub then wound its way through the patient's body till it reached the brain, where the crew could then destroy a blood clot using laser guns.
Of course, this was pure science fiction. It was the plot of the movie Fantastic Voyage, a phantasmagorical thriller in which the intrepid crew of the Proteus had just one hour to save the life of a top scientist, while avoiding such dangers as voracious white blood cells, lymph nodes and enemy spies. As a kid, I was enthralled by the film: secret agents, giant man-eating antibodies, and Raquel Welch as a sexy scientist – it was a boy's own fantasy.
In real life, we're a long way from shrinking people and sending them inside someone's body to carry out surgical procedures. But we are able to use nanoparticles as intravenous "couriers" to deliver drugs to specific parts of the body, or to sneak tiny Trojan horses into cancerous cells to destroy them from the inside.
Collateral damage
Throughout medical history, particularly in the treatment of cancer, the story has often been one of the cure being almost as bad as the disease. Chemotherapy may be an effective way of destroying cancer cells, but the damage to healthy tissue and organs can be devastating. There must be ways to more
accurately target cancer cells
and destroy them without the heavy collateral damage – and nanomedicine is doing just that.
In Ireland, pioneering research into nanomed is being done at Crann, the Centre for Research on Adaptive Nanostructures and Nanodevices, Trinity’s largest research institute.
Two leaders in the field of nanomedicine, Prof Yuri Volkov, chair of molecular and translational medicine and director of research at the TCD School of Medicine, and Prof Adriele Prina-Mello, are working together to develop ways to accurately attack illness using nanomaterials. Prof Volkov, whose team was working with cells and molecules and signalling processes, joined up with Prof Prina-Mello, whose team were perfecting nanomaterials.
“It was the result of an opening up of a large-scale interdisciplinary collaboration within the college. And it merged into something where you can apply those nanoparticles for treatment and benefit in the biomedical setting. That’s how it’s developed,” says Prof Volkov.
Prof Volkov also co-ordinates a Europe-wide consortium called Namdiatream, which co-ordinates expertise from around the EU to create nanotech toolkits for early diagnosis and treatment of cancer.
Nanomedicine is a relatively young science, but already it is making great strides, and, says Prof Volkov, nanoparticles are already being used to target disease at the cellular and even molecular level.
“We are dealing with very small structures which are positioned in between the individual atoms, and small biological molecules such as proteins,” says Prof Volkov.
We’re talking about yokes a mere handful of atoms thick – you wouldn’t be using a tweezers. So how do you manipulate nanomaterials, and how can you even see what’s going on at that level?
“First, of course, you need to have the very strong support of the underlying technologies,” says Prof Volkov. “And very powerful microscopic tools and imaging devices. That’s important, because without those we wouldn’t even be able to tell what we are doing.”
Nanobullets
The idea of sending nanoparticles into a cancerous cell to deliver a “bomb” to destroy it from the inside would have been science fiction 10 years ago, but it is happening now, says Prof Volkov, although he prefers to call it a “nanobullet”.
“If you’re talking in terms of weapons, when you have a bomb that explodes, it hits the target, but it also hits everything around it, whereas a laser guided missile, for example, made it possible to precisely hit the target.”
“If you take a conventional drug like aspirin or paracetamol, any of the drugs which people swallow and are water-soluble, it goes everywhere, and the focus of pain is silenced, but what happens to the other organs and tissues? They didn’t require this paracetamol, so they get the side-effect because they don’t need it. But if you combine that water-soluble molecule with a nanoparticle, it will limit its penetration to certain organs. You might for example make sure that it doesn’t go through the brain or to the eyes or to the lungs.”
But don’t expect to be able to go into your local GP and zap a tummy bug or a cold sore with nanoparticles any time soon.
The focus for the moment is firmly on the big three societal diseases: cancer, heart disease and diabetes.
Little devils Can nanoparticles turn bad?
In Michael Crichton’s sci-fi novel Prey, rogue nanoparticles take on the potential to swarm together and attack their creators. Should we be concerned about medical treatments that will allow these little nanodevils to swirl around inside our bodies?
There are three possible ways to dispose of nanoparticles floating about in your body, says Prof Volkov.
“One of these is, they will be biodegradable: they will cease to exist after they have done their job. The second is, they are so small they are easily flushed out of the system, through sweat, through urine, through the kidneys, or even coughed up. That’s the reason for having such small dimensions. And the third is that these particles can be biologically reutilised, such as those based on iron material. Many of our cells need iron to function – we breathe because we have haemoglobin. So some of these nanomaterials can be reutilised for a good purpose.”
If you're still worried about the effect of nanoparticles on your innards, nano-research is as strictly regulated as any other medicinal research, and subject to FDA and European Medicines Agency, says Prof Volkov.
“Prior to inserting any kind of nanodrug into a human, we have to remember we are trying to develop something which is good for mankind, and a quarter of the research effort is targeting the adverse side-effects of these nanoparticles. So testing in terms of bio-compatibility, it’s an absolute must, and it’s a rule which we strictly adhere to while developing new types of nanomaterials.”
Kevin Courtney
