The blood-brain-barrier (BBB) which protects our brains by being impenetrable to toxic substances in the bloodstream, has always been a problem for researchers because some drugs could not cross the barrier. In this instance, however, scientists were able to breach the blood-brain barrier, using tightly focused ultrasound to effectively part the brain’s protective curtain.
To get medication directly to the site of the patient’s malignant brain tumour, scientists infused the patient's bloodstream with a chemotherapy drug and also with tiny, microscopic bubbles, which are smaller than red blood cells and can pass freely through blood.
Using MRI-guided low intensity sound waves, the team targeted blood vessels in the blood-brain barrier near the site of the tumour and used ultrasound waves to vibrate the microbubbles, which in turn loosened the tight cell junctions that hold the blood-brain barrier together. With the junctions loosened sufficiently, the chemotherapy drug flowed past the barrier and deposited within the targeted tumour site.
This amazing breakthrough is the result of close to two decades’ research by researchers at Sunnybrook Research Institute and industry partner Insightec, and could pave the way for addressing all manner of brain diseases, and not just cancer – but also Alzheimer’s disease, Parkinson’s disease, psychiatric conditions and more.
“Breaching this barrier opens up a new frontier in treating brain disorders,” said Neal Kassell, chairman of the Focused Ultrasound Foundation, which funded the research. “We are encouraged by the momentum building for the use of focused ultrasound to non-invasively deliver therapies for a number of brain disorders.”