The article goes on to contradict its own headline. They are repairing hearts unfit for transplant using skin cells. They have not grown a full-sized heart.
Your objection is that they're not also growing the matrix from scratch? Personally, I don't find that to be an interesting distinction. All I care about is that we're getting closer to viable custom replacement organs. I expect the same is true of the people who did the work and those who wrote the headline.
And to add to this, if you can take a cadaver heart, strip it to the scaffolding, and then using a plurpotent stem cell line from your own cells to convert that structure into a functional heart, which can then be transplanted into you without risk of rejection, well that would be pretty much a game changer for all those people dying from congestive heart failure.
Tissue engineering has come a long way. The possibility of building a replacement organ this way is pretty interesting to contemplate in terms of changing peoples lives.
On a Nova Science Now episode they were also talking about using animal organs for their scaffolding.
There is lots of developments like this that looked pretty amazing, 5 years go when i first saw it, why isn't there an easy way to keep track of things like this?
It is a very important distinction. It is the difference between three sizable but incremental advances - rehabilitating unsuitable donor organs, the potential to use pig organs, and elimination of immune rejection - and the far, far greater advance of being able to grow entire patient-matched organs from scratch as needed with no donor.
Being shackled to the need for a donor organ for tissue much thicker than a centimeter is a big drag on the progression of this field. It is a function of blood vessels, largely - being able to create scaffolds of sufficient complexity and size with the right chemical guides to allow formation of blood vessel networks is still not there yet. Hence the need for the natural scaffold of the donor organ.
I don't think I understand. If they could rehabilitate unsuitable donor organs and didn't have to worry about rejection, there wouldn't be a shortage. Isn't that the end game?
No shortage is more like it. Intact cadaverous hearts are plentiful by comparison to awaiting heart transplant patients. Most heart failures are immediate and fatal, but people who have progressive failure are relatively rare. Transplant patients would conceivably be donors for the program (since most heart damage is soft tissue failure).
This is a key distinction. When you make a scientific claim, it has to be accurate, and in this case, they clearly did not grow a heart from scratch.
"SCIENTISTS GROW FULL-SIZED, BEATING HUMAN HEARTS FROM STEM CELLS" makes it sound like they just dumped stem cells in a petri dish and got a fully-functioning, properly shaped heart. Beyond being useful for creating custom replacement organs, that would imply we had godlike powers, because you can't grow a fully functional organ in isolation like that (building that matrix is entirely non trivial, as it happens in concert with all the organs growing around it).
Currently decellularized matrix (being stuck to nature's blueprint as you say) is the best substrate for regenerating heart tissue. Artificial matrices we can create (including 3D printing) have nowhere near the complexity of what exists in nature.
That is incorrect. They are not repairing hearts unfit for transplant. They are using human hearts (that are unfit for transplant) as a source of decellularized matrix. That decellularized matrix is then used to re-grow heart tissue using iPS-derived cardiomyocytes (heart cells).
I believe the scaffold is a pretty well known 'substrate' requirement for stem cells and is somehow secondary, the previous attempts were much more prototypal nut sized heart.
Two months ago, my dad died of a heart attack. One thing I've been wondering, and I'm hoping one of you can tell me, is why they couldn't have put him on some sort of machine until a replacement was found. This seems like as good a place as any to ask.
They said he was still alive when he got to the hospital, just barely, but the heart had too much damage to recover. My suspicions have been that either he died before he got there, and they didn't want to tell us that, or that they chose not to save him for some reason relating to insurance not being good enough. Neither is a rosey picture.
I'm sorry for your loss. My dad had one recently, a real slap in the face to change his habits, and he recovered well enough to keep speaking and remaining cane mobile. Gosh now that I think about it that was last September.
I've thought about the same thing though. I think it has to do with brain damage, broken ribs from CPR and other related issues to keep someone alive.
When I saw this pulseless heart a few years back I imagined we'd be seeing them more and more to the point of, as you alluded too, being able to hook someone up to a "heart."
Carmat are making the most progress with an artificial heart, but it is only in clinical trials. The battery is a backpack with a power cord fed in behind your ear. Unfortunately for your dad, we just aren't there yet with fixing a broken heart. In 10 to 20 years, probably.
Likewise. I think (just from experience; can't back it up at all) that interesting but 'non-core' posts - as in not directly CS-related or startup-y - tend to fall off quicker. But then, because they are interesting, garner a good number of upvotes again on subsequent reposts even just days later.
> HN does seem to have a herding mentality with upvotes
Yup, all these idiot sheeple upvoting or posting an interesting article just because they hadn't actually seen it or gotten a chance to read it yet. Why can't people just go back 30 pages in HN? Glad you can feel better than them, though; at least that was a silver lining.
You don't want to do that. Pig hearts are notoriously less durable (soft tissue tends to fail quickly, like in a fraction of a decade), so there's not a lot of data on the longevity of the circulatory stability of porcine hearts. I wouldn't ever get a porcine or cadaverous tissue transplant - as someone who pays close attention and has been living with an artificial valve for decades. (Human-) Cadaverous scaffolding, sounds ok on the surface. Let's see how much of it and specifically what parts are left intact after the growth process.
They do. Porcine hearts are a more reliable, consistent, and easily obtainable source for decellularized heart matrix. It's a great tool for experiments to develop the technology. Transplantation however is a different story.
