Researchers at ETH Zurich have developed a method for concentrating and releasing drugs in the brain with pinpoint accuracy. The team published their findings in Nature Communications.
Scientists used low energy ultrasound waves to cause the drug carriers to aggregate at the desired site within the brain. "What we're doing is using pulses of ultrasound essentially to create a virtual cage from sound waves around the desired site. As the blood circulates, it flushes the drug carriers through the whole brain. But the ones that enter the cage can't get back out," study leader Mehmet Fatih Yanik explains.
During their following steps, they used a higher level of ultrasound energy to get the drug carriers to vibrate at this site. Shear forces destroy the lipid membranes around the drugs, releasing the drugs to be absorbed by the nerve tissue present at the site. Then, the team demonstrated the effectiveness of the new method in mouse models. First they encapsulated a neuro-inhibitory drug in the drug carriers. Then, using the new technique, they successfully blocked a specific neural network connecting two areas of the brain. The team was able to show in the experiments that only this one particular part of the neuronal network was blocked and that the drug did not act on the entire brain.
"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," Yanik says. According to the team, in their experiments on rats, the quantity of drug that they used was 1,300 times smaller than the typical dose needed.