Harnessing bioelectronic solutions

Throughout the human body, electrical signals control many operations that are central to our everyday functioning. These signals travel through the nervous system and help our brain to interpret the world around us, and our body to carry out its necessary functions. External stimuli including sights, smells, and more are translated into electrical signals and interpreted by the brain. For example, when light hits the retina, it gets turned into electrical signals which travel to the brain and are interpreted as visual images. The growing field of bioelectronics develops implantable devices that can target these electrical signals to treat a range of conditions. This research is promising for areas including prosthetic vision devices and treatment of neurological or mood disorders, among other possibilities. 

Researchers in Assistant Professor Brian Timko’s lab in the Department of Biomedical Engineering recently published a paper in the journal Device about their innovative work developing a bioelectronic device using microcoil arrays. Other authors on the work are lead author and recent PhD graduate Vineeth Raghuram, EG21, along with collaborators Aditya Datye and Associate Professor Shelly Fried from the Department of Neurosurgery at Massachusetts General Hospital.

The team used small implantable microcoils that maximize the accuracy of the neuronal activation targeting while minimizing negative impacts on the body such as inflammation. Compared to other methods like transcutaneous electrical nerve stimulation, microcoil magnetic stimulation allows for more specific targeting, within 40 micrometers of the tip of the device. These microcoils can also be incorporated within soft flexible materials, making them suitable for placement near complex 3D structures in the body such as the innermost surface of the retina or on engineered tissues. The soft material coatings can reduce toxicity and opens avenues to tune the mechanical properties of the device to match the surrounding tissue.

Previous research on magnetic stimulation has mainly focused on single channel devices, but Timko and team developed a multi-device array that has the potential to create high-acuity biological inputs encoding visual or tactile cues. To demonstrate the versatility of their approach, they achieved localized activation of two different areas: cortical neurons and retinal ganglion cells, both of which process visual information. While further research is needed, the results of this study demonstrate the potential of magnetic stimulation devices for brain-machine interfaces and could open new routes toward bioelectronic therapies including prosthetic vision devices.

The Timko Lab is focused on exploring hybrid biological systems that integrate living cells with synthetic polymer or solid-state materials. Synthetic components can impart new functionalities in biological systems, for example by providing bioelectronic inputs and outputs or providing chemical or topographic cues that guide the maturation of engineered tissues.

Read the full paper, “Transparent and Conformal Microcoil Arrays for Spatially Selective Neuronal Activation,” in Device. Learn more about Assistant Professor Brian Timko and about the Timko Lab at Tufts University.