Magnetic Nanoparticles Could Kill Hard-To-Reach Tumors

Researchers at Oregon State University have developed an improved technology that allows for the more accurate targeting of magnetic nanoclusters to kill deep-seated cancer tumors such as those found in prostate cancer.

Magnetic nanoclusters are multi-atom collections of magnetic nanoparticles, which are tiny pieces of matter as small as one-billionth of a meter. Magnetic nanoparticles are used to treat tumors easily accessible by syringe, allowing the nanoparticles to be injected directly into the cancerous growth.

For hard-to-reach tumors, the researchers have come up with a technology called magnetic hyperthermia that are designed to locate and attack them. This technique uses an alternating magnetic field (AMF) to heat magnetic nanoparticles injected into a tumor.

The nanoparticles are exposed to an AMF, which causes the nanoparticles to reach temperatures in excess of 100 degrees Fahrenheit. This extreme heat kills the cancer cells.

The challenge facing Oregon State University was finding the nanoparticles efficient enough to do the job. Olena Taratula and Oleh Taratula of the OSU College of Pharmacy tackled the problem by developing nanoclusters with enhanced heating efficiency.

The nanoclusters they developed are hexagon-shaped iron oxide nanoparticles doped with cobalt and manganese and loaded into biodegradable nanocarriers.

“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 tumor," said Olena Taratula, an associate professor of pharmaceutical sciences.

She said their new nanoplatform is a milestone for treating difficult-to-access tumors with magnetic hyperthermia. The nanoclusters could potentially be optimized for even greater heating efficiency, she pointed out. But she noted their product is still a proof of concept.

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

"It's already been shown that magnetic hyperthermia at moderate temperatures increases the susceptibility of cancer cells to chemotherapy, radiation and immunotherapy," Olena said.

Future studies need to use orthotopic animal models where deep-seated tumors are studied in the location they would actually occur in the body to advance this technology.