New nanoclusters cook and kill cancer cells

Magnetic nanoparticles have shown promise in treating cancer, but their effectiveness depends on being able to inject them directly into a tumour.

Hexagon-shaped iron oxide nanoparticles doped with cobalt and manganese (Image: OSU)

Once injected into the tumour, the nanoparticles are exposed to an alternating magnetic field (AMF) that causes them to reach temperatures in excess of 100oF to kill the cancer cells.

This technique, however, doesn’t work for certain types of cancer that are hard to reach and are better treated with a ‘systemic’ delivery method such as intravenous injection, or injection into the abdominal cavity.

Now, researchers at Oregon State University have focussed on ovarian cancer to develop nanoparticles that, when administered systemically in clinically appropriate doses, accumulate in the tumour well enough to allow the AMF to heat and kill cancer cells.

Olena Taratula and Oleh Taratula of the OSU College of Pharmacy are said to have tackled the problem by developing nanoclusters, multiatom collections of nanoparticles, with enhanced heating efficiency. The nanoclusters are hexagon-shaped iron oxide nanoparticles doped with cobalt and manganese and loaded into biodegradable nanocarriers. Their findings have been published in ACS Nano.

“There had been many attempts to develop nanoparticles that could be administered systemically in safe doses and still allow for hot enough temperatures inside the tumour,” said Olena Taratula, associate professor of pharmaceutical sciences. “Our new nanoplatform is a milestone for treating difficult-to-access tumours with magnetic hyperthermia. This is a proof of concept, and the nanoclusters could potentially be optimised for even greater heating efficiency.”

The nanoclusters’ ability to reach therapeutically relevant temperatures in tumours following a single, low-dose IV injection opens the door to exploiting the full potential of magnetic hyperthermia in treating cancer, either by itself or with other therapies, she added in a statement.

“It’s already been shown that magnetic hyperthermia at moderate temperatures increases the susceptibility of cancer cells to chemotherapy, radiation and immunotherapy,” Taratula said.

The mouse model in this research involved animals receiving IV nanocluster injections after ovarian tumours had been grafted underneath their skin.

“To advance this technology, future studies need to use orthotopic animal models – models where deep-seated tumours are studied in the location they would actually occur in the body,” she said. “In addition, to minimise the heating of healthy tissue, current AMF systems need to be optimised, or new ones developed.”