It is possible to take drugs through ultrasound

A team of Stanford Medicine researchers (USA) ha developed a non -invasive system that, through ultrasound, can administer medications In any part of the body with a precision of a few millimeters, preventing drugs from reaching places where they should not, which produces unwanted side effects.

The system uses nanoparticles to encapsulate drugs along with ultrasound to release them in the planned destinations. In a new study published in ‘Nature Nanotechnology’, researchers demonstrate in rats that the latest version of their system can administer ketamine to specific regions of the brain and analgesics to specific nerves of the extremities. Thanks to a new formulation, they ensure that nanoparticles are safer, more stable and easier to produce.

“It turns out that only a little sugar is needed for this to work,” he says Raag Airanthe principal researcher. What they did was put 5% sucrose inside the liquid of the particles. That small amount caused the nanoparticles to behave: stable at body temperature but sensitive to ultrasound. In the blood they travel quietly, and only They release the drug where the narrow beam of ultrasound stimulates them.

With this tactic, they assure that you can Maximize the therapeutic effect and minimize side effectssays Airan.

They designed everything again

Ultrasound drug administration is not new to this group: in 2018 they already tested a system capable of releasing Propofol In areas of the rats brain. But that first prototype had problems: the particles requested rare processes to manufacture them, had to be saved to -80 ° C. And the drug is I escaped with ease a Body temperature.
“The clinical applicability of that system was quite limited. We had a real need to devise something different, so we returned to the design table,” says Airan.

They used to use liposomes (deck phospholipid), the same boxes that are used for the Arnm In vaccines against Covid. As Airan says, “there is an entire infrastructure to make liposomes as a pandemic by -product. We now know very well how to manufacture them.”

Why does it work with sugar?

For ultrasound to recognize the particles, they must have a acoustic impedance different from your environment. “Whenever there is a difference in acoustic impedance between a particle and the medium, a physical interaction with ultrasound will occur,” says the researcher.

After trying polymers, salts and others, the solution was culinary: “What can make things dense and viscous? Well, sugar could do it,” says Airan. With a 5% sucrose They found the right point: the particle responds to ultrasound and does not lose drug ahead of time.

The exact mechanism by which sound causes release is not totally clear, but the authors believe that the ultrasound It oscillates the cover against the densest nucleus and are created by They let out The medicine.

In experiments, by directing ultrasound to a concrete area of ​​the brain, the nanoparticles delivered approximately three more times drug there that in other areas. Although the target part received only one 30% more Of ketamine that free ketamine, that difference was enough to alter brain function clearly. “It is not just that we are getting the Desired effect. We are getting more than we would expect, taking into account the amount we are administering to that part of the brain, “says Airan.

Focal anesthesia without punctures

They also tested with Ropivacaine for Block pain In a concrete nerve: they injected the nanoparticles on another site and applied ultrasound to the Cyatic nerve. Result: in 2.5 minutes One occurred local anesthesia that lasted at least one hour. This could avoid direct injections in painful areas and reduce discomfort to patients.

Now, and with a sight in human essays, they expect the approval of the FDA. The intention is to test the system using Ketamine to treat the emotional component of the Chronic pain In people.