You’ve snapped them, popped them, blown them – but have you ever considered that bubbles could be used in conjunction with ultrasound to open the blood-brain barrier and allow medical treatment for conditions ranging from tumors to Alzheimer’s? Luckily for those of us who have not, others have.
The publication Science reports that this month in one of the first clinical tests, Todd Mainprize, a neurosurgeon at the University of Toronto, will pair ultrasound and microbubbles to target brain cancers. The ultrasound is the same as that used during pregnancy. The microbubbles are made of the patient’s blood. When introduced into the blood stream at the same time an ultrasound is being performed, the bubbles expand and contract. In response, the blood-brain barrier becomes “leaky” enough to permit the introduction of chemotherapy drugs.
Kullervo Hynynen of the Sunnybrook Research Institute in Toronto is the original developer of the ultrasound/microbubble method. Hynynen used this method to stimulate the brains of mice with a condition that mimicked Alzheimer’s. The microbubble action is thought to have stimulated the inflammatory response in the mice brains against the protein that clumps during Alzheimer’s. His results, as well as those of others working with mice, have been encouraging. In all cases, the treated mice have shown improved memory and cognitive functioning.
In a related study in New Zealand, microbubbles were introduced into the brains of mice with a different model of Alzheimer’s. The ultrasound was scanned “in a zigzag pattern across each animal’s entire skull, rather than focusing on discrete areas as others have done.” After treatment for six to eight weeks, the mice showed a complete restoration of memory.
Whether or not these treatments will be effective in humans remains to be seen. For one thing, the question of scarring on the brain must be addressed. And, as Brian Bacskai, a neurologist at Massachusetts General in Boston who studies Alzheimer’s points out, the difference between a mouse that can learn and one that cannot learn, “is pretty small.” Because of this its possible the gains made by mice may be insignificant to those required for similar improvement in humans.
Still, it’s exciting to look forward to a time when having a bubble brain will be an indication of good health.