To the naked eye, organoids aren’t much to look at. They’re basically tiny blobs. Closer inspection reveals their true complexity: these lab-grown balls of cells can resemble miniature organs. So far, organoids have mostly been used for research. But teams have started transplanting them into animals with the hope of curing disease. Humans are next—albeit some way off. Let’s say in 10 years … maybe.
The best known of these organoids are probably minibrains—clumps of neurons that are meant to mimic the way cells fire in a full-grown brain to a very limited extent. Debates have raged over whether these tiny blobs could ever be conscious, feel pain, or think—and over whether they should be called “minibrains” at all, given how far removed they are from a fully developed human brain.
We are arguably a long way off from transplanting miniature brain blobs into people (although some have tried putting them in rodents). But we are getting closer to implanting other organoids—potentially those that resemble lungs, livers, or intestines, for example.
The latest progress has been made by Mírian Romitti at the Université libre de Bruxelles in Belgium and her colleagues, who have successfully created miniature, transplantable thyroids from stem cells.
The thyroid is a butterfly-shaped structure in the neck that makes hormones. A lack of these hormones can make people very sick. Around 5% of people have an underactive thyroid, or hypothyroidism, which can lead to fatigue, aches and pains, weight gain, and depression. It can affect brain development in children. And those who are affected often have to take a replacement hormone treatment every single day.
After growing thyroid organoids in a lab for 45 days, Romitti and her colleagues could transplant them into mice that were lacking their own thyroids. The operation appeared to restore the production of thyroid hormones, essentially curing the animals’ hypothyroidism. “The animals were very happy,” as Romitti puts it.
The focus is now on finding a way to safe...