Doctors develop a breakthrough technique to deliver drugs across Blood Brain Barrier

22 Feb 2019

Canada’s medical researchers have found a breakthrough method to deliver chemotherapy drugs using a new ultrasound technique to breach the brain’s protective membrane and sneak past the stubborn blood-brain barrier.

According to a report from CTV News, a team of Canadian doctors has successfully injected chemotherapy drugs and a mixture of gas in the form of smaller bubbles to breach the blood-brain barrier temporarily and effectively deliver the drugs to its desired location.

The method doesn’t stop here. After injecting the microbubbles, Canadian surgeons beamed a kind of ultrasound waves towards the brain cancer patient’s skull so that the injected bubbles could vibrate and enter the brain passing through the blood-brain barrier.

According to the doctors (Dr. Todd Mainprize, Dr. Kullervo Hynynen, and their team) from the Sunnybrook Health Sciences Centre in Canada, about ten patients with brain cancer will be treated in the same way as part of a preliminary trial. This method has been performed for the first time on a 56-year-old female patient who is suffering from a brain tumor.

Dr. Mainprize said in a statement:

“Our surgery was done in a highly focused and precise fashion. It did not require a surgical craniotomy upfront and was minimally invasive. With this technique, you can selectively open almost anywhere in the brain and deliver whatever you want. Essentially, whatever you can think of is a potential study that may help in the future.”

Doctors hope to use this technology to deliver the drugs to the desired place and use the method in the treatment of other brain related diseases such as depression, Parkinson’s disease and Alzheimer’s disease.

Till now, BBB (blood-brain barrier) wasn’t able to deliver essential drugs for the treatment of any kind of brain diseases, due to its nature to protect the brain from foreign substances, disruptive hormones, neurotransmitters, etc.

This is not the first time doctors are researching on ultrasound technique to deliver medicines through the blood-brain barrier using microbubbles. In 2014, doctors from Pitié-Salpêtrière Hospital, Paris, have successfully used the same technique to send drugs through small bubbles by sneaking past the BBB with ultrasound waves. However, surgeons implanted an ultrasound inducer into the glioblastoma patient’s skull during the surgery.

Glioblastoma is an aggressive kind of brain tumor that arise from astrocytes—the star-shaped cells that make up the “glue-like,” or supportive tissue of the brain. Meanwhile, Canadian neurosurgeons used a much less invasive and more targeted technique to deliver the drugs to the brain.

Doctors used 3 stages of procedures to complete the surgery:

  1. Initially, liposomal doxorubicin, a chemotherapy drug will be injected into the patient’s bloodstream.
  2. In the second stage, microbubbles, small bubbles of air using mixed gas, will be delivered to the bloodstream intravenously (directly through veins).
  3. In the final stage, surgeons will beam ultrasound waves to the target area after locating the target area using MRI scanners. In this stage, blood-brain barrier will be breached to allow the chemo drug to enter the neural areas of the brain.

In this procedure, the microbubbles will not enter the neural areas of the brain, as they will be absorbed in the lungs when the ultrasound waves beamed. The breached BBB area will be healed and closed in eight to twelve hours. The very next day, doctors performed a traditional surgery to remove the tumor from the brain.

The results will be published formally, after using the same technique to deliver the chemo to neural areas of the brain of nine more patients. We wish them success, so that in the future doctors can deliver new drugs and therapies for Alzheimer’s disease, Parkinson’s disease and even stem cells.

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