Thaindian News

Washington, Jan 23 (IANS) Small plastic discs impregnated with tumour-specific antigens, embedded under the skin, can reprogramme the immune system to attack tumours, according to new research.The research - which rid 90 percent of mice of an aggressive form of melanoma that would usually kill the rodents within 25 days - represents the most effective demonstration to date of a cancer vaccine.

“Our immune systems work by recognising and attacking foreign invaders, allowing most cancer cells - which originate inside the body - to escape detection,” said David J. Mooney, professor of bioengineering at Harvard’s School of Engineering and Applied Sciences, who led the study.

“This technique, which redirects the immune system from inside the body, appears to be easier and more effective than other approaches to cancer vaccination.”

Most previous work on cancer vaccines has focussed on removing immune cells from the body and reprogramming them to attack malignant tissues. The altered cells are then reinjected back into the body.

While Mooney says ample theoretical work suggests this approach should work, in experiments more than 90 percent of the reinjected cells have died before having any effect.

The implants developed by Mooney and colleagues are slender discs measuring 8.5 mm across. Made of an FDA-approved biodegradable polymer, they can be inserted subcutaneously, much like the implantable contraceptives that can be placed in a woman’s arm, said a Harvard release.

The disks are 90 percent air, making them highly permeable to immune cells. They release cytokines, powerful attractants of immune-system messengers called dendritic cells.

These findings were described in the current issue of Nature Materials.