Dissolvable brain-compatible wireless sensors monitor brain injury

Dissolvable brain implant consisting of pressure and temperature sensors (bottom right) connected to a wireless transmitter. Photograph: John A. Rogers/ University of Illinois at Urbana-Champaign

A miniaturized wireless electronic device has been developed by scientists and neurosurgeons at Washington University School of Medicine, St. Louis and University of Illinois at Urbana-Champaign. The device can monitor temperature and pressure when implanted into the brains of mice. These implants naturally dissolve and resorb into the soft tissue once they are no longer needed.

Electronic implants are used widely in the treatment of numerous medical conditions, ranging from pacemakers and defibrillators given to cardiac patients, electrode arrays used for deep brain stimulation in patients with Parkinson’s Disease, and devices used to monitor intracranial temperature and pressure inside the skulls of people with severe traumatic brain injuries.

There have been several limitations associated to these devices, since implantation always carries a minimal risk. It could be cumbersome of the working of the device, wires and components open to bacterial breeding leading to infection, malfunctions if replacing is required leading to distress for removal and insertion for the patient. The development of this new device is said to overcome these limitations.

This device consists of a pressure and temperature sensor, the size of a minuscule, which is embedded onto a biodegradable silicon chip. This chip that is connected to a wireless transmitter on the outside, sits on the surface of a brain. The testing of this device was done on rats and the results delineated that the changes in intracranial pressure and the temperature occur as the rats’ alternate between consciousness and sobriety, following an anesthetic administration. This device is also unique in its way of being made of natural materials – assorting to “green electronics”. This allows it to be fully biodegradable and bio-compatible, and they function for a few weeks after which they completely dissolve on immersion into watery fluids, like cerebrospinal fluid.

To test it on the actual brain tissue to address its potential use, the researchers examined it on the brain tissue. They found no indication of inflammatory response, or any damage near/on the site which confirmed bio-compatibility of the device. They also modified the device to show its usage for the same measurements from sites about 5 mm below the surface of the rat brain. The researcher confirmed that these modifications can be done in different ways to monitor other physiological parameters, or to deliver drugs to the brain with micro-electrode incorporation.

This device has a promising use owing to its safety, cheaper fabrication process, environmental-friendliness. Hopefully, the researcher can utilize it for testing it in human clinical trials.

The original article can be found here.