Brain implants that detect neurological symptoms and automatically release drugs to treat them could one day be used to treat patients suffering from epileptic seizures.
Researchers from the University of Pittsburgh have designed tiny electrodes coated with a drug-loaded polymer, which were implanted in cultured rat neurons.
Multi-electrode arrays (MEAs) — small devices that can control or record the electrical circuitry in neurons — have long been used as a way of measuring neuronal activity and transforming this into an action; technologies such as ear implants and cardiac pacemakers have benefited from them.
Recent advances, however, have allowed MEAs to be coupled with devices that release specific drugs in order to test how neural circuits function, as well as investigating the underlying mechanisms within neuronal cells.
Based on the electrical-conducting properties of the polymer Polypyrrole (PPy), the researchers demonstrated a novel way of loading specific drugs onto an array of electrodes and triggering their release into cultured neurons, allowing for a more precise insight into the cellular mechanisms of neuronal networks.
‘By directly loading a drug of interest onto an individual electrode site and using an electrical signal to trigger its release, we can precisely control the drug-delivery site with ease,’ said Prof X Tracy Cui.
On top of this, the researchers have also demonstrated how the release of drugs could be informed, in real time, by the recording of activity in neurons — a step essential for creating a closed-loop system that both diagnoses and treats symptoms simultaneously, creating several potential applications.
‘We envision an implanted device in the future that will monitor brain activity, detect or predict an onset of epileptic seizure and send the command to the electrode at the most appropriate location, releasing an anti-convulsive drug to prevent the seizure,’ Cui said.