Mayo Clinic researchers have developed a nanoparticle capable of both shrinking breast cancer tumors and preventing new ones from growing. Published in Nature Nanotechnology, a study found a nanoparticle injected in mice could reduce tumor size by 70 to 80 percent.

The "Multivalent Bi-specific Nano-Bioconjugate Engager" includes nanoparticles covered with antibodies targeting HER2 receptors, which are found in 40 percent of all breast cancers. The nanoparticle is able to help the body recognize HER2 and attack the tumor, while also sending information to the T-cells to prevent recurrence.

"Our study represents a novel concept of designing nanomedicine that can actively interact with the immune cells in our body and modulate their functions to treat human diseases," said Betty Y.S. Kim, MD, PhD, the study's principal investigator and a neurosurgeon at Mayo Clinic's Florida campus. "It builds on recent developments in cancer immunotherapy, which have been successful in treating some types of tumors; however, most immunotherapy developed so far does not harness the power of the entire immune system. We've developed a new platform that reaches tumor cells and also recruits abundant clean-up cells for a fully potent immune response."

Researchers observed mice injected with the nanoparticles showed a 70 to 80 percent reduction in tumor size as well as resistance to future tumor growth when exposed to additional cancer cells a month later. The anti-tumor immune responses show the nanoparticles functioned much like a cancer vaccine, opening doors to further research into vaccinations for other diseases.

"In this proof-of-concept study, we were astounded to find that the animals treated with these nanoparticles showed a lasting anti-cancer effect," said Kim. “Unlike existing cancer immunotherapies that target only a portion of the immune system, our custom-designed nanomaterials actively engage the entire immune system to kill cancer cells, prompting the body to create its own memory system to minimize tumor recurrence. These nanomedicines can be expanded to target different types of cancer and other human diseases, including neurovascular and neurodegenerative disorders."