Doctors breach the blood-brain barrier for the first time

A team of Toronto doctors has, for the first time, opened up the blood-brain barrier so that therapeutic drugs could be delivered, according to a statement from Sunnybrook Health Sciences Centre.
The blood-brain barrier is designed to allow only water, some gases, and lipid-soluble molecules to enter the brain from the blood. Its primary benefit is the prevent infections in the blood from entering vulnerable brain tissue. However, the barrier is also a hindrance to doctors trying to treat brain cancer and other diseases on the “wrong side” of the barrier.
“The blood-brain barrier has been a persistent obstacle to delivering valuable therapies to treat disease such as tumors,” said Dr. Todd Mainprize, a neurosurgeon and principal investigator of the cutting-edge endeavor. “We are encouraged that we were able to temporarily open this barrier in a patient to deliver chemotherapy directly to the brain tumor.”
To breach the barrier, researchers first injected a radiation treatment drug, then microbubbles, into the bloodstream of an individual with a deadly brain tumor. The microbubbles are smaller than red blood cells and are harmless to the body.
The scientists then used cutting-edge MRI-guided low-intensity ultrasound to target blood vessels in the brain near the tumor. Over and over again, the waves compressed and expanded the microbubbles, making them vibrate and loosen tight junctions of the cells, comprising the blood-brain barrier. Once the barrier was breached, the chemotherapy drug flowed into the targeted regions.
What this means for future treatments
“Some of the most exciting and novel therapeutics for the treatment of malignant brain tumors are not able to reach the tumor cells because of the blood brain barrier,” Mainprize said. “This technique will open up new opportunities to deliver potentially much more effective treatments to the targeted areas.”
The successful use of the technique is the culmination of around two decades of work, the study team said.
“The success of this case is gratifying,” said Dr. Kullervo Hynynen, Director of Physical Sciences at Sunnybrook Research Institute. “My hope now is that many patients will eventually benefit from it.”
“We are encouraged by the momentum building for the use of focused ultrasound to non-invasively deliver therapies for a number of brain disorders,” added Dr. Neal Kassell, chairman of the Focused Ultrasound Foundation.
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Feature Image: University of Alberta