Study details and key findings

Two primary elements of vaccines are antigens and adjuvants. An antigen is a portion of a disease-causing pathogen that the immune system is primed to recognize and eliminate. An adjuvant is an ingredient that can increase the immune response to an antigen.

"In recent years, we have come to understand how important the selection of the adjuvant is because it drives the second signal that is needed for the correct priming of T and B [immune] cells," said Prabhani Atukorale, an assistant professor of biomedical engineering at the University of Massachusetts Amherst's Riccio College of Engineering.

Previously, Atukorale developed a lipid nanoparticle-based drug design that could shrink or eliminate tumors in mice. In the new study, researchers used the nanoparticle system to encase the adjuvants and melanoma peptide antigens in a vaccine combination, which was then given to mice. After three weeks, the mice were exposed to melanoma cells.

Overall, 80% of the mice who were vaccinated with the "super adjuvant" nanoparticle vaccine remained tumor-free until the end of the study, which lasted 250 days. In comparison, mice that were unvaccinated or had been vaccinated with a non-nanoparticle formulation developed tumors, and none survived past 35 days.

The mice who received the nanoparticle vaccine were also protected against the spread of cancer to their lungs. All the other mice in the study developed tumors in their lungs.

"Metastases across the board is the highest hurdle for cancer," Atukorale said. "The vast majority of tumor mortality is still due to metastases, and it almost trumps us working in difficult-to-reach cancers, such as melanoma and pancreatic cancer."

The researchers also conducted a second experiment where they combined the nanoparticles with tumor lysate as the new antigen. Tumor lysate refers to killed cancer cells that are taken directly from a tumor mass.

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According to the researchers, the nanoparticle design provides a platform approach that could be applied to several different types of cancers.

"By engineering these nanoparticles to activate the immune system via multi-pathway activation that combines with cancer-specific antigens, we can prevent tumor growth with remarkable survival rates," Atukorale said.

In the future, the researchers hope that the platform can be used to develop both therapeutic and preventive cancer treatments, particularly for people who have a high risk of cancer. To expand the research into this technology, Atukorale and Kane have partnered together on a startup called NanoVax Therapeutics.

"The real core technology that our company has been founded on is this nanoparticle and this treatment approach," Kane said. "This is a platform that Prabhani developed. The startup lets us pursue these translational efforts with the ultimate goal of improving patients' lives."

Currently, Atukorale and Kane are working to extend this technology to a therapeutic vaccine and have taken the initial steps to de-risk the technology in translation.