'Nanoburrs' only stick to damaged areas of the artery
A molecule designed to find, latch onto, then treat hardened arteries could offer a new way to tackle heart disease, say its inventors.
Nanoburrs, developed at the Massachusetts Institute of Technology (MIT), target only damaged cells in blood vessel walls.
Once attached, they can release drugs in precisely the right place.
But the British Heart Foundation warned the technology was some years from being used in patients.
The hardening of the arteries which supply the heart, or atherosclerosis, can eventually lead to blockages which can cause heart attacks.
The study in the Proceedings of the National Academy of Sciences journal says specialists normally use tiny balloons to force open the vessels, then place a tube called a stent inside to keep it open.
Often the process triggers a rapid re-growth of tissue around the stent which can lead to the artery blocking again, and a recent advance has been a stent which releases drugs for a number of days after insertion to keep this process under control.
The MIT approach offers another way to get these drugs to exactly the right place.
Its nanoburrs are coated with proteins which can only stick to a structure in the blood vessel wall called the "basement membrane".
This is only exposed when the wall is damaged, so only damaged sections of blood vessel are targeted.
Once in place, a reaction takes place to release the drug over a prolonged period - up to 12 days so far.
Long way off
Professor Robert Langer, one of the authors of the research, said: "This is a very exciting example of nanotechnology and cell targeting in action."
He said the technology could target any condition in which the cell wall was compromised in this way, including certain types of cancer, and other inflammatory diseases.
Professor Peter Weissberg, medical director of the British Heart Foundation, said that while the technology was "promising", there were many time-consuming obstacles to overcome before it could be regularly used in patients.
He said: "This is an interesting proof of principle. People have been looking for a long time for ways to target a particular drug to a particular part of the body.
"It wouldn't be able to replace the need for a balloon and stent to open an artery, but it's possible that one day, it may be able to deliver a drug to treat atherosclerosis itself."