Grace Chua, Straits Times 6 Feb 10;
FIRST, bioengineer Robert Langer's laboratory at the Massachusetts Institute of Technology (MIT) developed a gecko-inspired bandage, with super-sticky ridges modelled after a lizard's feet.
Now, a Singaporean PhD student there has come up with another potential winner inspired by nature. She has developed tiny particles that can cling to damaged artery walls the way lovegrass burrs stick to clothing.
These 'nanoburrs', which find their way to damaged blood vessels and slowly release drugs there, can reach parts of the artery that other treatments, such as stents, are unable to.
'We designed tiny particles that carry drugs precisely to the area of disease,' said 26-year-old MIT doctoral student Juliana Chan.
This avoids side effects that can occur when drugs are delivered to the whole body, she added.
Miss Chan, an Agency for Science, Technology and Research (A*Star) scholarship holder, was lead author on the research paper, which was published in the Proceedings of the National Academy of Sciences last month.
She is among a growing number of A*Star scholarship holders - from the programme that began in 2000 - named as first authors in respected scientific journals such as Nature and Cell.
Currently, the treatment for clogged or damaged arteries involves a vascular stent, which props open the artery and releases a drug - paclitaxel, for example - to prevent scarring and stop the artery from closing again.
The nanoburrs are covered with tiny molecules that seek out the basement membrane of a blood vessel and bind to it. The basement membrane is a layer that lines blood vessel walls, but is exposed only when those walls are damaged.
At the target site, the nanoburrs can release drugs over a period of 12 days.
The nanoparticles will either be used in tandem with stents, or in areas not well suited to stents, such as forks in an artery, the researchers hope.
The team is testing the nanoburrs in rats and aims to move on to tests on rabbits or pigs, to find out what doses are most effective.
The nanoparticles could be altered to zero in on tumours and deliver paclitaxel there as well, as it is also a cancer drug.
Cardiologist Chester Drum of Brigham and Women's Hospital in Boston, who was not directly involved in the work, said current therapies that accompany stent placement are limited to preventing clots, and the nanoparticles could deliver medicine to more areas of damaged tissue at a time to repair them.
'This type of systemically delivered nanoparticle technology opens up future possibilities of addressing the underlying disease more directly,' Dr Drum said.
'The significance of the result lies more in the delivery method than the drug delivered,' he added. 'In principle, a multitude of drugs could be delivered.'
