Big surprises in little things

A UCD researcher is studying ways to get tiny nanoparticles to carry drugs into cells, writes CLAIRE O'CONNELL.

A UCD researcher is studying ways to get tiny nanoparticles to carry drugs into cells, writes CLAIRE O'CONNELL.

IT'S ONE THING to make a drug that can treat a disease. It's quite another to get it to go where it needs to in the body to be effective. That's why researchers at University College Dublin are working out how to get tiny nanoparticles safely into cells, and in doing so they are unveiling some big surprises.

Nanoscience, or the study of particles on the scale of millionths of millimetres, has become a hot topic in research over the last decade. Engineered nanoparticles now offer the potential to deliver drugs to combat conditions like cancer, viral infections and neurodegenerative disease, which can lurk in currently hard-to-reach places in the body, according to Prof Kenneth Dawson, who directs the NanoBio Institute at UCD.

"Nanomedicine could really be the only means to cure some of these diseases," he says. "The portals to get into some of those places are so small that unless you go to that size you are not getting in."

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But while the size of a particle is important for gaining access, so too is its behaviour in the body, and so far we understand little about how materials on the nanoscale interact with living systems, says Prof Dawson.

His team is now working to find out what really happens to nanoparticles in biological environments such as the bloodstream, where they are surrounded by thousands of proteins. And what they are discovering is writing the rulebook for the brand new field of "bionanointeractions".

They believe that when a nanoparticle enters a complex, living system like the body, it doesn't remain bare. Instead it draws onto itself a cloak or "corona" of proteins from its surroundings. And it's this outer mantle of protein on the nanoparticle's surface that interacts with cells, argues Prof Dawson.

"The nanoparticle becomes a scaffold and the size still remains important, but it's only an enabling thing. What really matters is the corona," he says.

Depending on the nature of the protein corona that a cell sees, it may allow the nanoparticle in or block it out, and this is where the key lies to harnessing the body's own recognition processes and targeting drug delivery into cells, explains Prof Dawson.

"We believe that if you can understand how to read and control this code, then we can control where the nanoparticles go to, and ultimately that's the route to deliver things."

So far, Prof Dawson's team has sent nanoparticles right into the heart of cells, which he describes as a "canonical moment", and last month they picked up the prestigious 2007 Cozzarelli Prize in physical sciences from the US National Academy of Sciences for their work on understanding the nanoparticle-protein corona.

Prof Dawson is continuing to research the field by leading the Science Foundation Ireland-funded BioNanoInteract Strategic Research Cluster, which brings together scientists from universities around Ireland and abroad, and several industry partners.

"This is a sort of turning point," he says. "These are the processes the cells use, we are just getting [ into cells] by harnessing them because that's how cells work and how nature deals with things in the body. We are just learning how to create our things as part of the body's system and we are probing how it all works. This will have a lasting effect on nanomedicine."

And while the impact of their work on nano-drug delivery is obvious, Prof Dawson believes that understanding how nanoparticles interact with biological systems will also help promote safety across the board on the nanoscale.

"This will enable not just the development of new and safe drugs, but will support the development of safe and responsible practices for the overall development of nanotechnology," he says.