Waking up Immune System Using Nanoparticles

Cancer cells avoid getting targeted by the body's immune system by tricking it into believing that everything is normal. A new study suggests that nanoparticles inserted into tumor cells can act as tiny alarm clocks that can wake up the immune system.

Nanoparticles are so small that a billion of them could fit on the head of a pin. Their small size makes them an ideal candidate to be used to jumpstart the immune system. Researchers envision that someday doctors might be able to send a variety of payloads with nanoparticles into cancer cells. Antibodies, viruses, metal particles and drugs can also be attached to nanoparticles and sent into tumor cells.

Researchers at Yale and Johns Hopkins had earlier shown that nanoparticles can carry drug to brain tumor sites.

The current study makes use of a different approach to kill cancer cells.

"Our lab's approach differs from most in that we use nanoparticles to stimulate the immune system to attack tumors and there are a variety of potential ways that can be done," said Steve Fiering, PhD, Norris Cotton Cancer Center researcher and professor of Microbiology and Immunology, and of Genetics at the Geisel School of Medicine at Dartmouth. "Perhaps the most exciting potential of nanoparticles is that although very small, they can combine multiple therapeutic agents."

Researchers say that it is possible to get the immune system attack a tumor by sending a "foreign" body into cancer cells.

The team is testing one strategy that uses a combination of metal particles and heat. Nanoparticles with iron, silver, or gold are readily absorbed by the tumors. Magnetic energy, infrared light or radio waves is used to activate the metal particles. The interaction creates heat and kills cancer cells. The resulting heat even wakes up the immune system, which then sends its tumor fighting cells to kill remaining cancer cells.

Even ancient Egyptians knew that cancers can be treated using heat.

"The use of heat to treat cancer was first recorded by ancient Egyptians. But has reemerged with high tech modern systems as a contributor to the new paradigm of fighting cancer with the patients' own immune system," said Fiering in a news release.

Researchers caution that there is still a great deal of research that needs to be done to understand how nanoparticles could be used in cancer treatment.

The study is published in the journal Nanomedicine and Nanobiotechnology.