Friday, March 25th, 2022 -- Kit Parker’s team at Harvard University’s Wyss Institute has created biohybrid structures out of animal cardiac cells. Recently, they successfully created a “robofish” structure out of human cardiac cells to show how heart muscle contractions and pacemakers work.
The robot fish consists of 2 layers of human cardiac cells on each side, as well as plastic and gelatin for structure. The cells on both sides of the fish allow it to “swim” by contracting in a pattern similar to that of our own hearts. When one side of the fish contracts, the other side stretches and activates a protein to contract that same side. Then, the other side stretches, and the cycle continues. The robot fish twists and turns, swimming like how a zebrafish swims. Parker and his team also added a pacemaker called “G-node” to keep contractions at a constant rhythm.
After creation, the robot fish swam for 108 days, or 38 million “heartbeats.” The research team observed that the muscle cells developed and strengthened a lot throughout the first month; they became more coordinated, developed better contractions, and contracted faster. Eventually, the robot fish swam at speeds similar to those of wild zebrafish.
Also, the cells lived for much longer than expected. Most cells that are removed from animals only last for about 2 to 4 weeks. Therefore, the researchers believe that the cells lived longer because the contractions were monitored by both the cardiac cells and the G-node pacemaker.
The results of this project bring researchers one step closer to making complex artificial hearts, such as long-lasting hearts made from human cardiac stem cells. This project brings new ideas for mimicking the structure, physical movement, and electrical impulses of real hearts. Parker and his team hope to treat pediatric heart diseases and improve regenerative medicine with future artificial hearts based on their project.
Researchers can continue to use the robot fish to understand how the heart works. For example, this project discovered that when heart muscles relax, blood pours into the ventricles in a more active process than we previously thought. The robot fish can also help scientists study arrhythmias and other heart diseases caused by dysfunctional heart signals. Therefore, treatments for heart diseases can be developed as well.
The robot fish is the research team’s third moving biohybrid, after a stingray structure and a jellyfish structure both made with rat cardiac cells. They are currently continuing to make more biohybrids inspired by animals for further research.
(2022) Robofish powered by human cardiac cells gives fresh insight into heart. In: New Scientist. https://www.newscientist.com/article/2307975-robofish-powered-by-human-cardiac-cells-gives-fresh-insight-into-heart/. Accessed 18 March 2022.
(2022) An autonomously swimming biohybrid fish designed with human cardiac biophysics. In: Science. https://www.science.org/doi/10.1126/science.abh0474. Accessed 18 March 2022.
(2022) Biohybrid fish made from human cardiac cells swims like the heart beats. In: Wyss Institute at Harvard. https://wyss.harvard.edu/news/biohybrid-fish-made-from-human-cardiac-cells-swims-like-the-heart-beats/. Accessed 18 March 2022.
Definition of Biohybrid. In: Merriam-Webster. https://www.merriam-webster.com/medical/biohybrid. Accessed 18 March 2022.
Definition of Pacemaker. In: Merriam-Webster. https://www.merriam-webster.com/dictionary/pacemaker. Accessed 18 March 2022.
Definition of Arrhythmia. In: Merriam-Webster. https://www.merriam-webster.com/dictionary/arrhythmia. Accessed 18 March 2022.
Biohybrid: made of biological and non-biological components
Cardiac: related to the heart
Pacemaker: a group of cells that maintains the rhythm of heartbeats
Arrhythmia: an irregular change in the heartbeat, which can be deadly