Here’s news that should get your blood pumping: A team of scientists has developed the first human “mini-hearts” in the lab to have clearly beating chambers. The organoids, or miniature organs, are no bigger than sesame seeds and were generated by self-assembly using pluripotent stem cells, as per Science Magazine.
The organoids mimic the working heart of a 25-day-old human embryo, and they may help humans solve the heart’s many mysteries like -why babies’ hearts don’t scar after they experience a heart attack.
Congenital heart defects, for instance, are the most common birth condition in humans, affecting around 1% of all live births. This by itself shows the need to develop more precise organ-like platforms, which is where the scientists come in, with their newly devised technique which was described in a study published in the journal Cell.
The scientists designed human pluripotent stem cells, which can separate into any kind of tissue, into various forms of cardiac cells to create heart organoids whose cells self-organize like — those in an embryo. The point was to create 3 tissue layers that make up a heart chamber’s walls, which are one of the first parts of the heart to form.
The organoids, which are around 2 mm in diameter and have survived more than three months in the lab so far, become structurally equal to the heart of a 25-year-old embryo in seven days. They just have one chamber and the main types of cells at this point of development. Besides, the heart’s clearly defined chamber beats 60 to 100 times a minute, much like the heart of an embryo at the same age.
“When I saw it the first time, I was amazed that these chambers could form on their own,” said lead author Sasha Mendjan, a stem cell biologist at the Institute of Molecular Biotechnology at the Austrian Academy of Sciences, to Science Magazine. “The amazing thing is that you see immediately whether the experiment worked and the organoid is functional since it beats—unlike other organs.”
Although the idea of a completely working artificial heart seems far off, for the present, the scientist will most likely focus on connecting beating heart organoids to vascular networks and testing whether they can pump blood. Nonetheless, these mini-hearts hold immense potential since they could constitute a powerful novel tool for our experiments on understanding human cardiac development and disease, which have generally depended on animal models.