New Ultrasound Therapy Could Help Treat Alzheimer’s, Cancer

livemint.com:

Ultrasound, the decades-old technology known for giving early glimpses of unborn babies, could hold a key to a problem that has long challenged drug developers: getting medicines to hard-to-reach places to treat diseases like Alzheimer’s and cancer. A cutting-edge approach that combines ultrasound waves with tiny bubbles of inert gas injected into the bloodstream can get more chemotherapy to tumor cells and enable drugs to breach one of the most stubborn frontiers in the human body—the blood-brain barrier. It is also being explored as a new way to deliver gene therapy.

“There’s an extremely wide variety of where this sort of drug delivery or augmentation with ultrasound and bubbles can take us," says Flemming Forsberg, professor of radiology and director of ultrasound physics at Thomas Jefferson University in Philadelphia. The effectiveness of drugs in treating diseases like cancer, Alzheimer’s and Parkinson’s is often limited by poor penetration into tissues, he says, whether in the brain or in tumors in other parts of the body. Getting Medicine to the Site To get to the places they are needed, many drugs must move from the bloodstream into surrounding tissue.

The medicines have to travel through the thin walls of the capillaries, the body’s smallest blood vessels, and reach the target cells. This is tougher in some parts of the body than others. Some tumors are surrounded by dense networks of connective tissue that are hard to penetrate.

In the brain, the capillary-wall cells are so tightly packed that they form a barrier that the vast majority of drugs can’t get through. The new approach relies on targeted ultrasound waves that cause vibrations in tiny bubbles that are injected into the bloodstream. The resulting