Scientists have successfully grown a human heart in the lab. Or rather, they've regrown an existing donor heart, using stem cells to replace any cells that might cause the recipient to reject it. This might possibly pave the way for fully lab-grown custom organ replacements that are 100% compatible with the donee.
The process is detailed in a new paper, and consists of stripping and rebuilding a donor heart, much like you'd strip and restore a classic car, only it's a human organ, and you're using stem cells instead of auto-paint and spare parts.
The team at Harvard Medical School uses detergents to wash away incompatible cells, cells that would cause rejection in a transplant recipient. What's left is a kind of neutral scaffold, which is then suffused in a solution with stem cells and nutrients.
Then, when the heart has grown to resemble immature but normal human hearts, it's jolted with electricity and—Frankenstein-like—it starts to beat. The team had previously done this with mouse organs, but now it has proven that functional human myocardial tissue can be grown in the lab.
What's more, the stem cells were themselves cleverly harvested, from regular skin. "The researchers took adult skin cells," says Popular Science, "and used a new technique with messenger RNA to turn them into pluripotent stem cells, the cells that can become specialized to any type of cell in the human body, and then induced them to become two different types of cardiac cells."
Several techniques are being tried to create or modify organs to provide patients with transplants that won't be rejected. Another new study approaches the problem from the other end, filtering antibodies from the recipient's own blood to prevent rejection of kidneys, and other projects are working on artificial organs.
With transplants in such short supply, and an aging population that will need ever more maintenance, artificial and lab-grown organs are likely to be big business in the future. And like any research, other discoveries are made along the way. For instance, the team behind this custom-grown heart thinks that its techniques could also be used to treat heart failure, repairing existing hearts rather than replacing them.