By Nathaniel Bowman

An implantable device developed at the Massachusetts Institute of Technology combines a miniature ultrasound array with a drug-delivery cannula to push therapeutic molecules farther into brain tissue than passive diffusion alone can achieve. In a study published in the journal Device, the researchers showed that their ultrasound device allowed molecules to spread further after being released, both in tissue models and in a mouse study. The work targets one of the most stubborn problems in neuro-oncology: getting  drugs to the cells that surgery leaves behind.

The device, named LUCID for Long-term Ultrasound-enhanced Convective Injection Device, is a flexible implant as thin as a sheet of cardstock. A drug-delivery cannula is 3D-printed directly onto an array of 24 miniature ultrasound transducers. These transducers generate ultrasound waves right at the tip of the needle, helping  drug molecules diffuse farther into tissue after they are released. The implant’s reservoir carries about 100 microliters of fluid, infusion is supplied by a passive osmotic pump, and ultrasound can be controlled wirelessly through Bluetooth. A small battery that can be recharged wirelessly powers the electronics.

“We have 24 transducers in one ultrasound array, which can help a given drug bypass the blood-brain barrier and enhance the drug infusion. The device also gives doctors options in terms of the size, the length, and the number of infusions,” says Canan Dagdeviren, an associate professor of media arts and sciences at MIT and the senior author of the study. After implantation, a wireless controller can be used to program the exact ultrasound dosages to be delivered, enhancing the reach of the delivered therapy.