January 5, 2009

New Nano Device Aids Drug Dispersal

Researchers found a more accurate way to deliver cancer drugs, by harnessing the power of gold nanoparticles.

They wrote in the journal ACS Nano that the system could release a number of drugs in a specific part of the body at desired times.

The device relies on the fact that different particles melt when exposed to different levels of infrared light. Therefore, different drugs on the particles could be released in a controlled way.

Researchers say delivering drugs directly to a specific site within the body is beneficial because you can use relatively toxic drugs without causing widespread damage to healthy tissue.

A number of trials are using nanoparticles to take drugs directly to the site of a tumor.

Doctors shine near-infrared light on the site, penetrating the skin to reach the tumor. It causes the particles to heat up and release the drugs contained inside.

The device developed by the MIT team involves two differently shaped nanoparticles which have separate melting points, meaning complex HIV/Aids drugs can be released in a controlled way at appropriate intervals.

"Just by controlling the infrared wavelength, we can choose the release time," said lead author Andy Wijaya.

Kat Arney, of Cancer Research UK, said that nanoparticles were a "hot topic in cancer research because they can directly target tumors 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."


Image 2: The top image shows a mixture of gold nanoparticles. The longer particles are called nanobones, and the smaller are nanocapsules. Bottom left: After the nanoparticles are hit with 800 nanometer wavelength infrared light, the nanocapsules melt and release their payload. Nanobones remain intact. Right: After the nanoparticles are hit with 1100 nanometer wavelength infrared light, the nanobones melt and release their payload. Nanocapsules remain intact. Image / Andy Wijaya


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