Blasts of Ultrasound Could Get Needed Drugs Into the Brain

There’s a barrier in your brain.

Composed of very densely packed cells in the capillary walls, it restricts the passage of substances of the wrong size or chemistry from the bloodstream. Like a locked fence around your home, the blood-brain barrier prevents intruders—such as infective bacteria—from entering.

But a locked fence can also keep out rescuers in an emergency, and the blood-brain barrier keeps out potentially helpful drugs that might be able to ease the suffering of the tens of millions of people with Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, amyotrophic lateral sclerosis, and other diseases of the central nervous system. Less than 5 percent of the roughly 7000 available drugs can get through. Basically, none of the large-molecule drugs can, severely limiting the options for new therapies.

But there’s hope. Blasts of ultrasound can temporarily open the barrier in tightly focused spots of the brain that are just millimeters in diameter. And engineers at Chang Gung University, in Taiwan, have recently come up with a much improved way of delivering that energy.