Autonomous biohybrid fish developed from human heart cells

Scientists have developed the first fully autonomous biohybrid fish from heart muscle cells derived from human stem cells. The artificial fish developed demonstrates how lab-grown heart tissue can be engineered to sustain a rhythmic beat indefinitely. Scientists say their ultimate goal is to develop an artificial heart.

First step on the road to artificial heart development

Researchers at Harvard and Emory University have built the first autonomous biohybrid device made from cardiomyocytes derived from human stem cells. Inspired by the shape and swimming movement of a zebrafish, the artificial fish has layers of muscle cells on both sides of the tail fin.

When the cells on one side contract, the other side lengthens and the tail turns to the contracted side. Then, in the previous step, the lengthened side contracts and while the other side is stretched, the movement is ensured as the tail turns to the contracted side again. When one side yawns, the opening of a mechanically sensitive protein channel is triggered, causing a contraction on the other side. Likewise, the contraction here triggers the movement on the other side, and the tail of the artificial fish can catch a continuous cycle of movement. Scientists state that the artificial fish has a closed loop system that can last more than 100 days without any intervention.

By examining the processes of developed artificial fish, they found that over time, as cardiomyocyte cells mature, the fish’s muscle coordination, contraction amplitude and swimming speed increase. After a while, the biohybrid fish was able to swim as quickly and effectively as a live zebrafish.

The research team thinks the biohybrid fish they’ve developed will help to understand the heart in more detail and to study diseases such as arrhythmia. The team aims to build even more complex biohybrid devices from human heart cells and develop artificial hearts.