Some researchers are working to discover new, safer ways to deliver cancer-fighting drugs to tumors without damaging healthy cells. Others are finding ways to boost the body's own immune system to attack cancer cells. Researchers at Penn State have combined the two approaches by taking biodegradable polymer nanoparticles encapsulated with cancer-fighting drugs and incorporating them into immune cells to create a smart, targeted system to attack cancers of specific types.

The odds of interacting with cancer cells can be improved by coating the outside of the nanoparticles with antibodies or certain proteins or peptides that will lock onto the cancer cell when they make contact. However, this is still a passive drug delivery technology. If the particle does not go to the tumor, there is no chance for it to bind and deliver the drug.

Researchers wanted a more active method of sending drugs to the cancer wherever it was located, whether circulating in the blood, the brain, or any of the other organs of the body.

Immune cells, which were built to respond to inflammatory signals, will be naturally attracted to the tumor site. This makes immune cells a perfect active delivery system for the  nanoparticles. The same technology is also likely to be effective for infectious or other diseases, as well as for tissue regeneration, author said.

In the first proof of their technology, the research groups targeted circulating melanoma cells. In a paper published in the journal Small, titled "Immune Cell-Mediated Biodegradable Theranostic Nanoparticles for Melanoma Targeting," the researchers report the use of a novel biodegradable and photoluminescent poly(lactic acid) nanoparticle, loaded with melanoma-specific drugs with immune cells as the nanoparticle carriers. They showed that the immune cells could bind to the melanoma cells under shear stress conditions similar to those in the bloodstream. These experiments were all performed in the laboratory. Next they intend to perform studies in animal models and in solid tumors.

http://news.psu.edu/story/443539/2017/01/04/new-technique-uses-immune-cells-deliver-anti-cancer-drugs