Friday, November 13, 2015

Blood-brain Barrier Opened Non-invasively for the First Time

Should be easily reusable for stroke if our researchers find any drugs useful for angiogenesis, dendrite branching, axon pathfinding or even tPA delivery.
http://www.biosciencetechnology.com/news/2015/11/blood-brain-barrier-opened-non-invasively-first-time?
Scientists, for the first time, have non-invasively opened the blood-brain barrier (BBB) in a patient.
A team at Sunnybrook Health Sciences Centre in Toronto, led by neurosurgeon Todd Mainprize, M.D., used focused ultrasound technology to more effectively introduce chemotherapy drugs into a patient’s malignant brain tumor.  The results were verified with a post procedure MRI scan, Mainprize said at a press conference Tuesday.
The blood-brain barrier is a protective layer that keeps harmful substances such as toxins from entering from the blood vessels into the brain.  Unfortunately, it also prevents many drugs from reaching the brain in adequate doses.
At the press conference, Mainprize stressed that this is a phase one safety and concept study to show that they could pass through the BBB. He noted the operation went smoothly and the patient, a 56-year-old women, who is the first of 10 to undergo the procedure for the study, is doing well.
To breach the BBB, doctors infused a chemotherapy drug, along with tiny gas-filled bubbles, into the blood stream. Then focused ultrasound was applied to the tumor and surrounding brain, causing the bubbles to vibrate, and open the BBB so high concentrations of the chemotherapy could enter targeted tissues.
The team is actively analyzing brain tissue samples to see how much of the drug was able to enter.  The findings have not been published yet, but were presented at the Focused Ultrasound Surgery Foundation meeting, according to Mainprize.
Mainprize described the device: It has 1,024 transducers that are arranged in a helmet shape that goes around the head and the forehead, and corrects for aberrations in the skull.
While the BBB has been non-invasively opened in animals, this was the first instance in humans.
“There have been hundreds and hundreds of animal models opening the blood-brain barrier, in mice, dogs, pigs, and primates, all of which have shown a very good safety profile with no changes in function behavior or hemorrhage,” Mainprize said at the press conference.
He noted that this is a reversible procedure, and the barrier is restored back to its normal function in 24 hours.
Nathan McDannold, Ph.D., associate professor of radiology at Brigham and Women’s Hospital said, “If you compare this to alternative methods, whatever risks there are, there much less than if you were invasively injecting drugs.”
The scientists believe the technology has applications beyond brain tumors, such as in Alzheimer’s and Parkinson’s diseases.
McDannold said that groups are in the process of planning a protocol that would deliver antibodies to clear amyloid proteins, associated with Alzheimer’s, and for Parkinson’s they are looking at neuroprotectives and potential gene therapies.
The trial is being funded by the Focused Ultrasound Foundation.

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