
How close are we to 3D printing the human heart? - benzine
https://humanbioscience.org/2019/08/how-close-are-we-to-3d-printing-the-human-heart.html
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echelon
What I don't understand is why we don't use existing biology as a tool. Why do
we have to go out of the way to create an exogenous heart? That's like
programming with magnetized needles. The human body is the perfect compiler
for growing human hearts (and other organs), yet we want to throw away
millions of years of evolution and try to roll our own.

I think you'd find much broader application if you cloned humans and neutered
the genes for cephalization. It's a little macabre, but think about it: you'd
have host bodies ready for organ harvesting and for medical or systems-level
biology research. You can even tweak them for whatever experimental (or donor
immunocompatibility) parameters you desire.

Of course you'd need to keep the headless bodies alive by hooking them up to
machines (at least initially), and deliver a steady stream of nutrients and
hormones for development, but this path opens up so many new and exciting
experimental pathways. It's revolutionary, but at the same time it's actually
kind of simple and elegant. And once you have a facility for growing and
maintaining the bodies, you can also produce new ones on site.

The kinds of experiments you couldn't ethically perform before are now broadly
available. You can destroy the host immune system, delete immunogenic
epitopes, build MHC libraries, etc. With thousands of bodies you could do
research rapidly, in situ.

This kind of setup also revolutionizes medical testing.

If I were a billionaire, I'd be investing in this instead of space rockets.
Space isn't hospitable for human bodies. We evolved for Earth. I'd wager we
either have robots or change our own biological makeup before we have
widespread space travel, so it makes sense to invest in the technological
reverse salient rather than the flashy sci fi one. Living longer, disease
free, gets us there faster.

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pazimzadeh
It's more than a little macabre, but hard to argue against if it does work. A
few questions:

What if embodied cognition is a bigger deal than we think it is? i.e. i) To
what degree do we need an active being to develop the various organs and ii)
The uncephalized body might not be that dead

One of the alternatives is using animal organs (xenotransplantation), and we
now have the ability to "humanize" them by genetically removing viruses and
altering their immunogenicity to decrease the chances of rejection:
[https://www.egenesisbio.com/technology/](https://www.egenesisbio.com/technology/)

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aiscapehumanity
I feel xenotransplants ethically eventually goes zero? A non cognitive shell
is less sentient than a clinic rared animal with sharable organs. Xtransplants
are a step up from food factory farming but doesnt do much for the rights of
non-humans still.

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pazimzadeh
You don't keep the animal alive indefinitely in a questionably vegetative just
to grow up its organs though - you let it roam about (likely in a caged and
germ free, granted, but hopefully large, facility) and when the time comes to
harvest the organ, you sacrifice the animal in a humane way.

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Jaruzel
Page is down.

Google cache copy:

[https://webcache.googleusercontent.com/search?q=cache:N5sMhg...](https://webcache.googleusercontent.com/search?q=cache:N5sMhgJK9ysJ:https://humanbioscience.org/2019/08/how-
close-are-we-to-3d-printing-the-human-heart.html+&cd=1&hl=en&ct=clnk&gl=uk)

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Roritharr
What happened to washing the cells from the underlying collagen structure and
using that as a scaffold?

Roughly ten years ago I saw a Nova Science Now episode on this and it looked
rather workable, so what's the state of that?

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Roritharr
I found a video of the episode:

[https://www.youtube.com/watch?v=jLs8DeHVkec](https://www.youtube.com/watch?v=jLs8DeHVkec)

around the 7 minute mark there is a pumping heart that was grown ontop of such
a scaffold.

~~~
Roritharr
Oh wow, the woman in the video had to undergo a lung amputation in 2016, and
everything shown in the video seems to be the culmination of a crazy amount of
unscientific experimentation on a patient:

> Macchiarini admitted that one year after the operation Claudia had to be
> repeatedly saved with a stent in her airways, a method which worked so badly
> for her before. Macchiarini and his team also claimed in 2014 to have been
> watching over his patient “every 3 months”.

>It was however too late. In July 2016, Claudia underwent a lung amputation.
Luckily, she was Macchiarini’s only trachea transplant patient in Barcelona, a
second operation was stopped due to technical formalities.

Here is the full, horrifying article.

[https://forbetterscience.com/2016/11/02/claudias-
trachea/](https://forbetterscience.com/2016/11/02/claudias-trachea/)

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Tharkun
Page won't load, so I can only speculate based on the title. Barring miracles,
the answer is "very far off". Sure, the macroscopic structure is relatively
simple. And sure, it's just a pump. But it's a pump with its own frequency
generator (SA node). Which supplies blood to itself. Which is self-repairing
to a large extent, in spite of the insane volumes of blood it pumps every
living moment and the stresses that puts on its own blood vessels. It's an
electromechanical Swiss watch, where timing is crucial and various types of
tissue have various conductive properties.

Good luck with the 3D printer. Maybe start with a valve that lasts longer than
a pig valve, move up from there.

Edit: nerve replacement would be a nice next step. Or simple muscle
replacement. Lots of people would benefit from that, and both are likely
prerequisites to "printing" a heart.

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Causality1
Not close. I think we'll see lab-grown meat with an identical taste get within
an order of magnitude of the cost of natural meat before lab-grown tissue
technology rises to the task of producing a functional heart at any price
point.

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boyadjian
We are very far from 3D printing the human heart, in fact, it will never
happen. A human heart can only be grown.

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gnikif
Why? I mean there are no constraints to printing it at least in theory.

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squirrelicus
Usually the rule with a title that ends in a question mark is that the answer
is no. In this case "not close" seems to be the answer. Rest assured, it's way
more complicated and there are a lot more problems to tackle than just
aligning ECMs.

That being said, I love this sort of thing so much. Maybe one day my grandkids
might be saved by this.

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wpasc
Betteridge's law; I love this sort of thing too, though I hope it comes sooner
and humanity/society breaks new ground in science at a more rapid clip
(compared to the morass many believe we are currently in)

~~~
squirrelicus
Well we kinda picked all the low hanging fruit over the last 150 years. Each
technological advancement seems exponentially more expensive.

