MIT's thin brain implant uses ultrasound to push drugs farther into tissue, aiming at brain tumors

MIT researchers have built a thin, flexible brain implant that releases drugs slowly and uses ultrasound to push them farther into surrounding tissue, MIT News reported on 26 October. The device, called LUCID, is aimed at glioblastoma, an aggressive brain tumor that often returns after surgery because surgeons cannot remove every cancer cell.

A drug reservoir on an ultrasound array

LUCID, short for Long-term Ultrasound-enhanced Convective Injection Device, is about as thin as cardstock. A 3D-printed drug cannula sits on an array of 24 miniature ultrasound transducers and holds about 100 microliters of fluid, released by a passive osmotic pump. It is controlled wirelessly over Bluetooth and has a rechargeable battery.

“We have 24 transducers in one ultrasound array, which can help a given drug bypass the blood-brain barrier.” — Canan Dagdeviren, MIT associate professor, senior author

Farther in a gel and in mice

In a gel that mimics brain tissue, ultrasound spread drug molecules much farther than delivery without it. In mice, an MRI contrast agent released by the device spread farther through the brain with the ultrasound switched on. MIT did not give numbers for how much farther. The work was published in the journal Device.

“Getting a drug into the brain is only part of the challenge,” said co-lead author Jason Hou. The researchers say the approach could also deliver immunotherapies or gene therapies, and could be used in organs other than the brain.

Far from patients

LUCID has only been tested in a tissue model and in mice, and it is not known whether it would prevent tumor recurrence or be safe in people. In a version for patients, the cannula and ultrasound array would sit inside the skull, with the battery and electronics outside. Researchers at Harvard and Massachusetts General Hospital were among the co-authors. Other ways of reaching the brain include a gene therapy that shut down brain-fluid production in mice.