The most common form of brain cancer, glioblastoma, kills just about 95 percent of its victims within just five years of diagnosis. Surgery and radiation are the usual tactics used against the deadly disease, but they have a very limited impact because of how aggressive glioblastoma is in consuming brain tissue around the primary tumor. Even chemotherapy often proves fruitless in combatting this growth. But a team of professors from the University of Virginia and Johns Hopkins University think they may have a solution that will save countless lives in the future.
UVa biomedical engineering professor Richard Price teamed up with his colleagues at Johns Hopkins to create a technique that will push through the blood-brain barrier – a selective permeability barrier that separates circulating blood from the fluid in the central nervous system and brain – at specific locations to enable “the passage of drug-bearing nanoparticles.”
Basically, the technique relies on microbubble technology to evade barriers that prevent chemotherapy from effectively reaching brain tumors. The soluble bubbles of gas are able to make their way through even the smallest capillaries. They can vibrate and move around in ways that temporarily open up small pores in adjacent blood-vessel walls, which means that the bubbles can actually be used to breach the blood-brain barrier.
That’s only the first step to reaching gioblastoma tissue, though. The second, UVa says, is “getting a therapeutic agent to diffuse through the brain once it is on the other side.” That’s where the team at Johns Hopkins comes in to play. The professors at Johns Hopkins create a nanoparticle completely coated with polyethylene glycol to allow it to diffuse through the brain as needed.
“We joined forces with John Hopkins because we each had a technology that addresses one of the two big physical barriers to drug delivery in the brain,” says Price. “We decided to put the two technologies together and see if that combination can actually produce efficacy.”
Price and his colleagues are loading the microbubbles and nanoparticles with different therapeutic drugs at the same time. They’re then using MRI to “paint the entire area where the tumor has infiltrated with ultrasound,” according to Price.
While their focus is currently on glioblastoma, the technologies applications aren’t limited to this one type of brain cancer. Price says that it could also potentially be used to treat Parkinson’s disease, depression or even obsessive compulsive disorder.