Gold nanorods to cook cancer from within
9 Jan 2012 by Evoluted New Media
Chemists in America have loaded more than 2 million gold nanorods into a single cancer cell in a breakthrough that could see the particles used as tiny heating elements to cook tumours from the inside.
Rice University researchers – led by associate professor of chemistry, Eugene Zubarev – demonstrated a large uptake of gold nanorods in cell culture experiments. The breast cancer cells they were studying were so laden with tiny gold nanorods that their masses increased by an average of 13%
“Remarkably, the cells continued to function normally, even with all this gold inside them,” said Zubarev.
It isn’t until they are activated by a laser that the nanorods – which are around the same size as a small virus – can harvest and convert harmless light into heat to kill cancer from within.
“Ideally, you’d like to use a low-power laser to minimise the risks to healthy tissue, and the more particles you can load inside the cell, the lower you can set the power level and irradiation time,” Zubarev said.
Graduate student Leonid Vidgeman said: “We hope that in the future we can use the nanorods to actually heat and cook the cancer cells from the inside.”
Vidgeman explained that gold nanorods have a special ability to absorb light and turn it into heat. By placing nanorods in cancer cells and shining a specific light into those cells, researchers can specifically target and kill the cancer while not affecting any of the other surrounding cells.
While the nanorods prove deadly once inside the cancer cells, getting them in there proved difficult. Cetryltrimethylammonium bromide (CTAB) – a soapy substance found in conditioners – makes the nanorods soluble in water. It encases the rods and gives them a positive surface charge which encourages cells to ingest them.
However, CTAB is toxic so the researchers developed a method to replace it with MTAB, a closely related but non-toxic molecule. MTAB forms a permanent chemical bond with the nanorods. The researchers also developed an optimal strategy to synthesis MTAB and substitute it for CTAB on the nanorod’s surface. They also developed a purification process to remove all traces of CTAB from a solution of nanorods.
The next stage of the research – published in Angewandte Chemie – is to use the technique in animal studies.
- See Videman and Zubarev talking about their research
