Ultrasound pulses activate release of drugs from nanoparticles.
Biomedical engineers at Johns Hopkins report they have worked out a noninvasive way to release and deliver concentrated amounts of a drug to the brain of rats in a temporary, localized manner using ultrasound. The method first “cages” a drug inside tiny, biodegradable “nanoparticles,” then activates its release through precisely targeted sound waves, such as those used to painlessly and noninvasively create images of internal organs.

Because most psychoactive drugs could be delivered this way, as well as many other types of drugs, the researchers say their method has the potential to advance many therapies and research studies inside and outside the brain.

They also say that their method should minimize a drug’s side effects because the drug’s release is concentrated in a small area of the body, so the total amount of drug administered can be much lower. And because the individual components of the technology – including the use of the specific biomaterials, ultrasound and FDA–approved drugs — have already been tested in people and found to be safe, the researchers believe their method could be brought into clinical use more quickly than usual: They hope to start the regulatory approval process within the next year or two.

“If further testing of our combination method works in humans, it will not only give us a way to direct medications to specific areas of the brain, but will also let us learn a lot more about the function of each brain area,” says Jordan Green, PhD, associate professor of biomedical engineering, who is also a member of the Kimmel Cancer Center and the Institute for Nanobiotechnology.

Details of the research were published on Jan. 23 in the journal Nano Letters.