These so-called cyborg organoids, developed by a team from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), are described in Nano Letters.
"I was so inspired by the natural organ development process in high school, in which 3D organs start from few cells in 2D structures. I think if we can develop nanoelectronics that are so flexible, stretchable, and soft that they can grow together with developing tissue through their natural development process, the embedded sensors can measure the entire activity of this developmental process," said Jia Liu, Assistant Professor of Bioengineering at SEAS and senior author of the study. "The end result is a piece of tissue with a nanoscale device completely distributed and integrated across the entire three-dimensional volume of the tissue."
According to Harvard SEAS, Liu had previously developed flexible, mesh-like nanoelectronics that could be injected in specific regions of tissue.
Building on that design, Liu and his team increased the stretchability of the nanoelectronics by changing the shape of the mesh from straight lines to serpentine structures.
The team is then said to have transferred the mesh nanoelectronics onto a 2D sheet of stem cells, where the cells covered and interwoven with the nanoelectronics via cell-cell attraction forces. As the stem cells began to morph into a 3D structure, the nanoelectronics reconfigured themselves along with the cells, resulting in fully-grown 3D organoids with embedded sensors.
The stem cells were then differentiated into cardiomyocytes - heart cells - and the researchers were able to monitor and record the electrophysiological activity for 90 days.
"This method allows us to continuously monitor the developmental process and understand how the dynamics of individual cells start to interact and synchronise during the entire developmental process," Liu said in a statement. "It could be used to turn any organoid into cyborg organoids, including brain and pancreas organoids."
In addition to helping answer fundamental questions about biology, cyborg organoids could be used to test and monitor patient-specific drug treatments and potentially used for transplantations.