A whole functional organ has been grown from scratch inside an animal for the first time, say researchers in Scotland.
A group of cells developed into a thymus - a critical part of the immune system - when transplanted into mice.
The findings, published in Nature Cell Biology, could pave the way to alternatives to organ transplantation.
Experts said the research was promising, but still years away from human therapies.
The thymus is found near the heart and produces a component of the immune system, called T-cells, which fight infection.
Grow your own
Scientists at the Medical Research Council centre for regenerative medicine at the University of Edinburgh started with cells from a mouse embryo.
These cells were genetically "reprogrammed" and started to transform into a type of cell found in the thymus.
These were mixed with other support-role cells and placed inside mice.
Once inside, the bunch of cells developed into a functional thymus.
It is similar to a feat last year, when lab-grown human brains reached the same level of development as a nine-week-old foetus.
The thymus is a much simpler organ and in these experiments became fully functional.
Structurally it contained the two main regions - the cortex and medulla - and it also produced T-cells.
Prof Clare Blackburn, part of the research team, said it was "tremendously exciting" when the team realised what they had achieved.
She told the BBC: "This was a complete surprise to us, that we were really being able to generate a fully functional and fully organised organ starting with reprogrammed cells in really a very straightforward way.
"This is a very exciting advance and it's also very tantalising in terms of the wider field of regenerative medicine."
Patients who need a bone marrow transplant and children who are born without a functioning thymus could all benefit.
Ways of boosting the thymus could also help elderly people. The organ shrinks with age and leads to a weaker immune system.
However, there are a number of obstacles to overcome before this research moves from animal studies to hospital therapies.
The current technique uses embryos. This means the developing thymus would not be a tissue match for the patient.
Researchers also need to be sure that the transplant cells do not pose a cancer risk by growing uncontrollably
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I can immediately see applications for this regarding new hearts for those who have heart disease, new kidneys, liver replacement...hell, grow a new set of lungs to help an ailing smoker. Very neat.
Oh hell yes, I needed an encouraging science pick-me-up today.
Baltar: "I don't want to miss a moment of the last Battlestar's destruction!"
Centurion: "Sir, I really think you should look at the other Battlestar."
Baltar: "What are you babbling about other...it's impossible!"
Centurion: "No. It is a Battlestar."
Corrax Entry 7:17: So you walk eternally through the shadow realms, standing against evil where all others falter. May your thirst for retribution never quench, may the blood on your sword never dry, and may we never need you again.
Borgholio wrote:I can immediately see applications for this regarding new hearts for those who have heart disease, new kidneys, liver replacement...hell, grow a new set of lungs to help an ailing smoker. Very neat.
I suspect it's not quite that easy. Lungs and livers are not small organs. You would be talking several months (at least) of discomfort and probably bed rest. Also, if you extract the old organs before you regrow new ones, you're going to have to substitute for them somehow.
With organs that come in pairs such as lungs and kidneys, I suppose you could do it one at a time...
With this, the computer bypass for spines, and the brain-like matter being grown, that's a lot of different progress in biotech. Does anyone know what sort of development life cycle exists before technologies such as this gets into mainstream healthcare, though?
In this case, the technique hasn't been proven to work reliably enough to be a viable medical treatment, even in animals, and it's probably going to be multiple rounds of animal testing before it reaches that point. Then you get into human testing, which is profoundly regulated and controlled.
In this case, the technique hasn't been proven to work reliably enough to be a viable medical treatment, even in animals, and it's probably going to be multiple rounds of animal testing before it reaches that point. Then you get into human testing, which is profoundly regulated and controlled.
And generally requires volunteers. Both healthy and ill. Which may not be the easiest thing to come by. At some point you have to go "okay, we just have to do this and see if it works", like they did with the heart transplant...
The Thymus atrophies at a very young age unlike other organs. Regrowing it is a matter of changing a single growth factor. Biology is usually not that nice so other organs will take a lot longer to regrow.
This is good either way because it will go a long way to showing normal people that rejuvenation treatments are possible. Go SENS
