'Backpacks' on white blood cells may aid cancer drug delivery

Researchers at MIT have discovered a new way to deliver targeted drugs to a specific target. By attaching a polymer drug-loaded target to a white blood cell, they can hitch a ride to sites in the body where drugs are needed and release the payload there.

The scientists created what they call "backpacks" for the monocytes, made from layers of polymer, and mounted them on the immune cells. They initially tried the cancer drug doxorubicin alone, which tended to leak out of the polymer, but packed into tiny liposomes, the treatment stayed in the polymer until it was needed.

"What we want to do is take advantage of immune cells whose job it is to seek out disease in the body, and use them to deliver cargo for us," Roberta Polak of MIT said in a statement. "How do we do that? Our lab developed cellular backpacks that can be loaded with therapeutic compounds and unloaded."

The liposomes they used were sensitive to ultrasound in a way that they can be opened with an external sound wave.

In mice, the drug-loaded cells with polymer backpacks accumulated successfully in locations where inflammation was occurring. In the future, the team is looking to use the delivery mechanism across the blood-brain barrier to also treat Parkinson's and Alzheimer's disease.

The MIT team collaborated with researchers from the University of North Carolina at Chapel Hill and presented their work at a meeting of the American Chemical Society on March 16.

- here's the release