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Sunday, March 21, 2010

Golden bullets for cancer

Killing tumor cells without harming normal tissue is the great challenge of cancer treatment. Carl Batt and his team from Cornell University are working on a way to do just that.

The researchers used a two step process to ambush tumor cells from the inside. They first attached an antibody specific to colorectal cancer cells to nanoparticles made of gold and iron oxide. The antibodies bound the tiny constructs to the surfaces of the cancer cells, which promptly engulfed the nanoparticles. The next step was to use a near-infrared laser on the cells. This low-powered laser has no effect on normal cells, but the gold inside the cancerous cells absorbs the radiation, heating and killing those cells. Tissue culture tests of this treatment have been promising.

Another team led by Younan Xia from Washington University used gold nanocages to achieve a similar effect. In their case, the targeting and killing of tumor cells in mice was successfully tested.

Infrared images made while tumors were irradiated with a laser show that in nanocage-injected mice (left), the surface of the tumor quickly became hot enough to kill cells. In buffer-injected mice (right), the temperature barely budged.
Photo credit: WUSTL

Xia and his colleagues are working to increase the specific uptake of the gold particles by tumor cells. In addition, they are considering filling the hollow nanocages with anti-cancer medicines.