Pop-Up Sensors Measure Electronic Signals in Cardiac Cells

Researchers at the University of California, San Diego have developed a small ‘pop-up’ sensor that can measure electronic signals propagating within heart cells. The technology consists of tiny spike-like bumps that can penetrate cell membranes without causing damage and that can detect electrical signals within individual cells and between cells in 3D tissue samples. The device could provide new insights into heart disease, including myocardial infarction and arrhythmias.

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Heart tissue inherently depends on electrical activity to function properly, and measuring this accurately at the single cell level and intercellularly could provide a wealth of information based on numerous heart conditions. However, inserting small electrodes into individual cells is difficult and can cause damage. This new technology aims to provide a less invasive way to achieve this.

“Studying how an electrical signal spreads between different cells is important to understanding the mechanism of cell function and disease,” said Yue Gu, one of the scientists who led the development of the new sensor. “Irregularities in this signal can be a sign of arrhythmia, for example. If the signal cannot propagate correctly from one part of the heart to another, then some part of the heart cannot receive the signal, so it cannot contract ”.

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Illustration of the device that interacts with the cells of the heart (above). The sensors can monitor electrical signals in multiple individual cells at once (lower left) and at two sites in a cell (lower right). Image adapted from Nature Nanotechnology

The base of the device is an array of tiny field-effect transistors that the researchers have coated with a phospholipid bilayer. This coating allows them to penetrate inside the cell without eliciting a foreign body response, which would make long-term measurements of electrical activity difficult. The tiny probes are sensitive enough to measure electrical signals within a cell, but they can also track signals that travel through multiple cells.

The device features a ‘pop-up’ structure, as the researchers joined the transistors together on a pre-stretched elastomer sheet, and when the stress was released, the transistors were erected to form a 3D structure. “It’s like a pop-up book,” Gu said. “It starts out as a 2D structure, and with the compression force it appears in some parts and becomes a 3D structure.”

So far, the UCSD team tested the technology on cardiac cell cultures in the lab and already gained some insight into the speed at which signals propagate through individual cells and groups of cells. However, the device may also have potential in neurological disease research and could allow researchers to study electrical impulses within neurons.

To study in Nature Nanotechnology: Three-dimensional transistor arrays for intracellular and intercellular recording

Via: University of California San Diego

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