Just like vaccines, which use a weakened flu virus in order to boost the immune system, the concept of treating one disease using a different one is not new. In fact, some of the original ideas for treating cancer with infections trace back to the late 1800s and have evolved into what we now call immunotherapy.
When the body senses a possible threat, it springs into action an entire defense system looking to eliminate the foreign cells, but other molecules, like a cancer cell, in this case, can also get caught in the cross fire. This is part of why biological therapies are so exciting, it’s a way of supercharging the body’s immune system to overpower the disease.
One of the issues with this approach is finding a suitable delivery method, and this is where the Virginia Tech team resorted to salmonella. The infection could even be augmented to smuggle cancer-fighting nanoparticles into the tumor in a huge abundance.
“Its (salmonella’s) job as a pathogen is to penetrate through the tissue”, explained Bahareh Behkam, associate professor of mechanical engineering. “What we thought is if bacteria are so good at moving through the tissue, how about coupling nanomedicine with the bacterium to carry that medicine much farther than it’d passively diffuse on its own?”.
The technology has been under development for years and was named Bacteria-Enabled Autonomous Drug Delivery System, or NanoBEADS. These agents are constructed by conjugating poly(lactic‐co‐glycolic acid) nanoparticles with tumor‐targeting Salmonella typhimurium. Their effectiveness was almost 100 times more than conventionally diffused nanoparticles.
Many obstacles had be overcome before reaching this point, and the work is still not done. “The process of creating nanoparticles and then attaching them to bacteria in a robust and repeatable manner was challenging, but add on top of that ensuring the bacteria stay alive, discovering the mechanism of bacteria transport in cancerous tissue, and devising ways to quantitatively describe the effectiveness of NanoBEADS, and this was a difficult project”, added Rick Davis, professor of chemical engineering and assistant professor of biomedical sciences and pathobiology.
This medical breakthrough could materialize into improved treatments for a wide number of cancers and lead to saving the lives of countless patients.