Human heart and brain cells use electrical currents to function and signal to one another. Reading and modulating electrical activities from these cells is the foundation of many biomedical tools, such as cardiac pacemakers and brain implants. The implantation process, however, always risks damaging important cell networks. To achieve seamless interfacing between cells and electronics with minimal damage, researchers lead by Prof. Jia Liu from the School of Engineering and Applied Sciences at Harvard University have created a “cyborg” organ by growing human stem cells with flexible, stretchable mesh electronics in a dish. The stem cells used can then be guided to differentiate (using chemical signals) into many different kinds of cells – heart cells, in this case. The result is a noninvasive platform for monitoring electrical activities of the heart cells both during and after organ development.
To create the cyborg organs, the researchers plated a 2D sheet of human stem cells on top of their designed 2D mesh electronics. The 2D sheet of cells was then guided to differentiate into heart cells and transformed into a 3D ‘heart’ structure. The soft mesh electronics use serpentine polymer ribbons that can stretch and compress without breaking, allowing the electronics to take different shapes after creation. Throughout the growing process, the electronic device becomes adhered to the cells, and is also transformed into the 3D structure. Once the cyborg organ had taken its 3D form, researchers were able to record the cells’ electrical activities both during guided differentiation into heart cells and after they form the cyborg organ. In addition, the electronic design led to minimal impact on tissue growth and differentiation when compared with non-cyborg organs.
This work presents an alternative approach to creating bio-machine interfaces and has demonstrated a novel method of integrating electronics with living tissue to monitor organ development and function. While the goal of this project was to create an implant, it’s not quite known yet how this technique can be integrated with a person’s already fully formed organs. However, in the meantime, we can use these cyborg organs to study diseases, screen pharmaceuticals, and who knows? Maybe one day we might be able to grow and monitor cyborg brains that are able to ‘think’ just like us.
Video Description: The beating cyborg heart at day 30 of differentiation. The serpentine ribbons are the soft and stretchable mesh electronics.
Managing Correspondent: Anqi Zhang
Original journal article: Cyborg Organoids: Implantation of Nanoelectronics via Organogenesis for Tissue-Wide Electrophysiology. Nano Letters.
Image Credit: Jia Liu group, Harvard University