Washington: A new technique may now make it possible to deliver cancer-fighting drugs to the targeted areas within hours, as against two days taken by existing systems.

Using lab mice, Case Western Reserve University (CWRU) researches slashed drug delivery time from two days to mere hours. Modelling this for human use will enable cancer patients to receive the required drugs within hours of injection.

The system uses gold nanoparticle vectors to deliver photodynamic therapy (PDT) drugs through the bloodstream to cancerous sites.

"Gold nanoparticles are usually not used for the PDT drug vector. However, gold is chemically inert and non-toxic," said Yu Cheng, CWRU graduate.

Photodynamic therapy utilises light-sensitive drugs that, when exposed to light of a certain wavelength, will energize and burn away cancer cells.

Because exposure to light activates these drugs, PDT patients must keep out of bright lights for days while the drugs make their way through the bloodstream to the cancer site.

"By shortening the waiting time from drug injection to activation, PDT patients are much less inconvenienced and tend to have a more normal lifestyle," said Clemens Burda, associate professor of chemistry and director of the CWRU Centre for Chemical Dynamics and Nanomaterials Research.

The drug delivery system uses a gold nanoparticle (Au NP) as its hub. Each Au NP is coated with polyethylene glycol (PEG) ligands, giving it the appearance of a hairy ball, said Burda. These PEG molecules offer several advantages over other materials.

They are soluble in fats and water, don't interact with proteins in the bloodstream and help protect the drug, keeping it safe and stable until delivery to the cancer site.

Burda says that a potential future research project would look at providing a time-release administration of the drug rather than a more all-at-once release. In the long term, Burda hopes to make the Au NP delivery system applicable to a broad range of diseases.

These findings will appear in the next edition of the Journal of the American Chemical Society. IANS