Print-On-Demand Bone Could Quickly Mend Major Injuries

sciencehabit quotes a report from Science Magazine: If you shatter a bone in the future, a 3D printer and some special ink could be your best medicine. Researchers have created what they call "hyperelastic bone" that can be manufactured on demand and works almost as well as the real thing, at least in monkeys and rats. Though not ready to be implanted in humans, bioengineers are optimistic that the material could be a much-needed leap forward in quickly mending injuries ranging from bones wracked by cancer to broken skulls. Researchers at Northwestern University, Evanston, in Illinois are working on a hyperelastic bone, which is a type of scaffold made up of hydroxyapatite, a naturally occurring mineral that exists in our bones and teeth, and a biocompatible polymer called polycaprolactone, and a solvent. Hydroxyapatite provides strength and offers chemical cues to stem cells to create bone. The polycaprolactone polymer adds flexibility, and the solvent sticks the 3D-printed layers together as it evaporates during printing. The mixture is blended into an ink that is dispensed by the printer, layer by layer, into exact shapes matching the bone that needs to be replaced. The idea is, a patient would come in with a nasty broken bone -- say, a shattered jaw -- and instead of going through painful autograft surgeries or waiting for a custom scaffold to be manufactured, he or she could be x-rayed and a 3D-printed hyperelastic bone scaffold could be printed that same day.

Marrow?

[ArtemaOne]

I'm curious as to the body's ability to use this for marrow. I know you could live without a portion of bone with marrow, much as people missing limbs do, but would marrow eventually grow inside of these bones? Just my immediate curiosity. Obviously this is awesome.

Re:

[DarkVader]

Given that marrow is rather fluid, if this is used for a hollow bone that contains marrow, the answer is going to be yes. They're showing samples of it in a hollow form, so clearly marrow containment is planned for.

Re:

[ArtemaOne]

However, I wonder about its ability to allow the marrow to function as intended. Will it attach properly? Is the material appropriately porous, and if not can it respond in similar ways to real bone? Just lots of questions and only hypothetical answers at this point.

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[dbIII]

I'm curious as to the body's ability to use this for marrow

It's not marrow, it's the hard stuff like on the surface of your teeth.
The body fills in the gaps just like around joint replacements.

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[ArtemaOne]

I think you think I thought something I didn't think. My curiosity was if it could be filled in the same as natural bone.

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[dbIII]

The key word to keep in mind here is "scaffold".
The body fills in the gaps like with the porous surfaces that started coming in on various titanium implants around 2000.
Adjacent bone grows into the gap.

Re:Marrow?

[dbIII]

I'm not sure if I was clear enough.
The way similar things have been used previously is they are butted up against real living bone, so the real bone, including the marrow, grows into the portion of the implant that is left open for this to happen.

Having something the same strength, density and hardness as existing bone has a lot of advantages. Each time the recipient moves the implant flexes against other things and a very hard surface grinds away bone into tiny pieces which can confuse white blood cells enough that they attack attached bone as well as the fragments, which means eventually hard implants end up being very loosely attached and need to be replaced with ones going into fresh bone.

Taking notes at a materials science conference twenty years ago has finally paid off :)

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[ArtemaOne]

That does make a lot of sense, and has a lot of similarities with other things. Brass is often used against steel to reduce wear on the steel, and mating between steel and aluminum should be reduced for similar reasons, eventually the aluminum will loosen considerably.

Slashdot Stories

[Dan East]

First we have

New California Law Allows Test of Autonomous Shuttle With No Driver

Followed by

Print-On-Demand Bone Could Quickly Mend Major Injuries

I think I sense a theme.

Yeah, about that

[Snotnose]

Broken bones take what, 1-4 months to heal depending on the bone and the break. If you replace the bone you need to cut off all the muscles/tendons/whatever cuz I'm not a doctor. How long will it take the muscles/tendons/other stuff to heal?

I live in San Diego. We've got 3 Chargers players out for the year due to tendon injuries. My understanding is they're a walk in the park to fix, but take months and months to heal, and a lot of the time you never get back to 100%

Did I mention I'm not a doctor,

Re:

[dgatwood]

They typically replace bones only when they are so completely destroyed that there's no hope of repairing them surgically, where the only options are grafts, transplants, other forms of bone replacement, metal plates, or amputation. I would assume that this would be similar, but less problematic than those other approaches.

print-on-demand bone

[Black Parrot]

could also eliminate the need for medicines like viagra.

Ya, but ...

[fahrbot-bot]

If you shatter a bone in the future, a 3D printer and some special ink could be your best medicine.

It will probably be an HP printer that requires genuine HP ink cartridges - so there's that.

Boned and can't get reboned.

Polycaprolacetone is really cool

[serviscope_minor]

You can buy polycaprolacetone (PCA) pretty readily. "Instamorph" is one brand, and you can also buy it from Alibaba by the metric tonne. It's a pretty decent thermoplastic, not all that dissimilar to ABS, but a little softer and more flexible.

The big thing is it melts at 60 degrees C and goes transparent when it's molten. It's also horrendously sticky when molten, especially to some plastics. It's fantastic stuff to keep around since you can use it to repair broken plastic items. If you have a small heat gun too, you can selectively rework and heat small areas.

Visual Mondegreen FTW

[Fieryphoenix]

I read the summary as referring to hyperrealistic bone until I reached the end.