Biofabrication

ASSOCIATE PROFESSOR MIA WOODRUFF, Biomaterials & Tissue Morphology Group: 3D printing has just really exploded into the human consciousness recently. They're doing everything from printing housing in China, they're printing 3D fashion on the catwalks of Milan, and biofabrication is really a biological take of 3D printing. So it enables us to create 3-dimensional anatomically precise tissue substitutes.

PROFESSOR DIETMAR HUTMACHER, Chair of Regenerative Medicine: Tissues such as bone, tissues such as breast, or cartilage.

WOODRUFF: And we can use these to treat traumatic accidents or congenital defects, or also with cancer excisions.

TITLE: How to 3D print a body

TITLE: Queensland University of Technology

WOODRUFF: So I'll take you through what goes on in this laboratory. Okay, so here we have a beautiful image of a patient who suffered a nasty trauma to the skull. So we start off by taking a scan of the patient. So if they're suffering from a large amount of bone loss from the head—for example, Michael Schumacher had a nasty head injury, say he had a large chunk of bone missing—we can take a scan of that defected tissue, and we can take a 3-dimensional map.

So here you can see a large piece of bone missing from the skull. So we can effectively map this image anatomically, and we can create this 3-dimensional map of a perfect tissue structure that fits into that defect site. And here's an example of what that scaffold would look like, one that we've designed. So you can see in 3-dimensions it will fit into that defect site.

NARRATOR: But this isn't just chucking a piece of 3D printed plastic in your head. What we're talking about here is something that will actually allow your tissues to regrow. In essence, it's scaffolding.

WOODRUFF: Which we can then add into that structure, for example, the patient's own stem cells. And they'll be added to that scaffold structure, they'll grow over time, they'll proliferate.

HUTMACHER: We are providing a temporary home for those cells to build the tissue we want to regenerate. 

WOODRUFF: All of this green tissue here is new bone that's formed, and it's growing inside the scaffold. And you can see little blood vessels that have formed, and all of the bone cells that are present within that structure.

Because it's the patient's own stems that are working, it's exactly the same as the tissue that would be healing normally, or would have been present in the first place. 

When we create these scaffolds, we can tailor them to degrade at a specific rate.

HUTMACHER: And it's very similar, to give you an example, if you would fall down today, and you would have a major cut off your knee, you would go to the surgeon or doctor and he would put stitches into your knee to stitch up your skin. In the old days, four weeks later you would need to go back to the surgeon, you would pull out the stitches, because they would be non-degradable. Nowadays, you don't need to go back to pull out the stitches, because these stitches are degradable. So we use the same type of materials now to build our scaffold.

WOODRUFF: So if we're healing skin, I'll just show you an example here, so here are scaffolds that were made from the same substance. You can see it's quite structurally flexible, like this. If we were making a bone, we'd want to be making it more tough and strong, like this. So as an example of a long bone, which you can see would fit quite easily into a tibial defect for example, here.

You can see that we have a very very fine stream of polymer laying down that little checked pattern. It's a process called melt electrospinning, which means that we're applying a voltage between the tip of that needle and the collector plate, and we're pulling off very fine fibres of polymer. And it's almost in the same structure as the collagen on your skin. And here's one we made earlier. Here's an example, this is the exact defect site we've just seen, so if you look at the skull here this is what we just saw on the computer screen, and you can see it's got this huge chunk of bone missing here. And we have 3D printed a scaffold, so we would implant that back into the patient. Obviously, in surgery—the surgeon would do this, and not the scientist—and over time that would slowly dissolve away, and the bone tissue would grow in through the scaffold, and eventually the defect would be healed, and look more like this.

NARRATOR: This technology could drastically change our decades-old methods of using metal implants.

RESEARCHER: The conventional therapeutic options were to resect this tumour, and to implant a metal prosthesis. But you see, it's huge. With a metallic implant, you have to exchange it after 15 or 20 years.

NARRATOR: But arguably the most powerful role of biofabrication will be with the disease that kills over 2,000 Australian women every year—breast cancer.

HUTMACHER: So this is an exact shape of the breast of the lady. We would scan the remaining breast, and then we would be able to fill all this space with the patient's own tissue. And then the surgeon would implant this, and then after 2 to 3 years, only the lady patient's own tissue would stay behind.

ASSOCIATE PROFESSOR OWEN UNG, Breast Cancer Specialist: The potential for this sort of reconstruction is a woman would have no fear of rejection of that tissue. Closer to naturalness than an artificial implant. Because the holy grail is to reproduce organs, and if you've lost a kidney it'd be great to grow a new kidney, if you needed another, a scaffold of bone, that would be great.

WOODRUFF: We're not going to be able to print a beating heart, but we are going to be able to create 3D printed artificial tissue subsitutes that will be able to replace a patient's heart one day. So we will not make it by printing a beating heart, but we'll make it by 3D printing a structure that is useful and is made of the right material and the right cells and the right growth factors and the right signals to ultimately be able to be implanted to help these people who need a replacement heart.

What we ultimately dream for is that just like every single office in the world has got a printer in the office and you're printing your A4 sheets of words for your meetings every day, we want to have a 3D printer in every single operating theatre in the country where a patient can admit, they can be scanned, and we can print that defected tissue replacement on the spot, to be able to implant it in a sterile manner back into the patient. So in the hospital of the future, for us, a 3D printer will be in every hospital.