Differently shaped gold nanoparticles can carry different drugs
US researchers say they have harnessed the power of gold nanoparticles to devise a better way of delivering drugs to treat diseases such as cancer.
The fledgling system could release a number of drugs in a specific part of the body at desired intervals, the MIT team wrote in the journal ACS Nano.
The device makes use of the fact that different particles melt when exposed to different levels of infrared light.
Different drugs on the particles could thus be released in a controlled way.
One of the advantages of being able to deliver drugs directly to a specific site within the body is that you can use relatively toxic drugs without fear of causing widespread damage to other, healthy tissue.
A number of trials are using nanoparticles, sometimes as small as one nanometre - or a billionth of a metre - to take drugs directly to the site of a tumour and avoid many of the side-effects associated with traditional chemotherapy.
Near-infrared light is shone on the site, penetrating the skin to reach the tumour. At the right temperature, it causes the particles to heat up and release the drugs contained within.
Spacing drugs out
But conditions such as cancer or HIV/Aids often require complex treatment with a number of drugs which have to be taken at different intervals.
The device developed by the MIT team involves two differently shaped nanoparticles which have separate melting points, meaning the drugs can be released in a controlled fashion at appropriate intervals.
"Just by controlling the infrared wavelength, we can choose the release time," said Andy Wijaya, the report's lead author.
In theory, the device could be used to deliver up to four drugs by creating four different shaped particles.
Kat Arney, of Cancer Research UK, said that nanoparticles were a "hot topic in cancer research because they can directly target tumours to deliver a payload of drugs".
"This new technique is clever because it means a number of different drugs can be released. But although it's exciting the work is still at an early stage and is not yet ready to be used in patients."