High-precision drug delivery to brain

According to a press release, scientists at the Swiss Federal Institute of Technology in Zurich (ETH) have succeeded in delivering drugs exactly where they are needed in the brain. To achieve this, they used focused ultrasound waves. With this new method, it will in future be possible to deliver psychotropic drugs, chemotherapeutic agents and other types of medication only to those regions of the brain where this is medically desirable, with the blood and other areas of the brain remaining unaffected. This should ultimately serve to substantially reduce any eventual side effects.  

This non-invasive method is controlled from outside the head by way of ultrasound. It involves special drug carriers that wrap the drugs in spherical lipid vesicles. These are then attached to gas-​containing ultrasound-​sensitive microbubbles, which are injected into the bloodstream and transported to the brain. In the first step, the scientists employ low-energy ultrasound waves that ensure that the drug carriers congregate at the desired site within the brain. In the second step, the researchers use a higher level of ultrasound energy to make the drug carriers vibrate here. Frictional forces destroy the external membranes of the carriers, ensuring that the drugs are released and absorbed by the surrounding nerve tissue.

“Because our method aggregates drugs at the site in the brain where their effect is desired, we don’t need nearly as high a dose”, comments Mehmet Fatih Yanik, Professor of Neurotechnology and study director. During his research team’s experiments on rats, for example, they administered a dose of the drug that was 1,300 times lower than would ordinarily have been required. As the press release explains further, the researchers will only be able to advance the method in humans once the efficacy and benefits have been confirmed in animal models.

This research project was financed by the EU funding program Horizon 2020. The findings from this resultant study have now been published in the trade journal “Nature Communications”.