To the Beat

Swimming like a fish, this biohybrid device, blending artificial and biological structures, is the latest tool designed by scientists studying the heart. Powering a fish shape made of paper and gelatine, with plastic fins, are two layers of cardiac muscle cells, derived from human stem cells. When cells in one layer contract, the others stretch, activating mechanosensitive ion channels in their cell membranes that cause them to contract in return, stretching the other side, and so on, in a continuous loop propelling the fish forward of its own accord. Researchers also engineered a group of cells to drive the rhythm of contractions, acting like the sinoatrial node, the heart’s natural pacemaker. Emulating the heart’s coordinated, autonomous beating, the fish remained active for over 100 days, and even improved its performance, swimming faster over its first month of activity. Monitoring its behaviour presents new opportunities to test how cardiac muscle operates.

Written by Emmanuelle Briolat

Emmanuelle Briolat

Writer

A researcher specialising in visual signals in Lepidoptera, camouflage and the effects of light pollution, Emmanuelle’s writing covers a range of topics, from biomedical research to children’s books about moth defences.

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• Video by Keel Yong Lee, Sung-Jin Park, David G. Matthews, George Lauder and Kevin Kit Parker
• Disease Biophysics Group, John A. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA, USA
• Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Research published in Science, February 2022