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Bioprinters to the organ rescue

OTTAWA — Layer-by-layer, living tissue is squeezed out of a nozzle. An intricate puzzle is formed based upon blueprints created by an ordinary computer.


But what is created is anything except ordinary — a human organ pieced together cell-by-cell by a printer.

These ‘bioprinters’ are a new breed of 3D printers that have the potential to create a medical breakthrough.

This breakthrough would be printing human organs viable for transplant.

These hands were printed out by Carleton University's 3D printers
Need a hand? 3D printers can accurately create models based off computer blueprints

“We want to build a whole organ, like kidney, liver or heart,” says Vladimir Mironov, an assistant professor in the Bioprinting Research Center at the Medical University of South Carolina (MUSC). 

Though researchers have used printers to attempt to replicate organs as early as 2003, Mironov pointed out that the prototypes printed now are called organ-like tissue construct, because they are not viable.  He says that it will take between 25 and 30 years before organs printed from machines can be transplanted into humans.

“People build blood vessels and it takes them 10 years.  People build artificial hearts, it took them 25 years,” says Mironov excitedly in his heavily accented English. “I don’t know what will happen in the future.  I’m not a technology forecaster.  What I can say is if you give me enough money, enough resources, maybe we can build this.”

Money and resources are certainly an important factor.  Mironov’s group receives $5 million U.S. from the National Science Foundation, and $75,000 U.S. from MUSC.

For Mironov, resources also include the printers themselves.

Evolving from 3D to 'bio' printers

The principle behind bioprinters is simple enough, according to Mark Kata of 360 Technical Services.  His company owns Neatco, which created the two bioprinters for Mironov.

'So imagine the pencil is the syringe, and hand is robotic hand.  That’s the printer.  And instead of ink, we have what we call bioink: cells and tissue.  That’s the principle of machine'

“The 3D printer sounds really high tech, but it’s not…It doesn’t matter if you’re dispensing live cells or ink or glue.  You’re just dispensing it.”

3D printers, such as the two in Carleton University’s Department of Mechanical and Aerospace Engineering operate on an X-Y-Z axis, allowing for left to right, back to front movement.

“Really it’s just a bunch of rods with bearings and a head moving back and forth,” says Stephan Biljan, who facilitates the operation of the department’s 3D printers.  “It pretty much works like a glue gun, where you take your material, heat it up and force it through a small orifice.”

The printer creates the desired object based on a computer-generated 3D blueprint.  The object is made layer-by-layer, as the warm plastic is squeezed through a nozzle on the printer, a process called fused-deposition modeling. 

Neatco’s printers are an example of modifying a 3D printer to perform new functions. It incorporated a special nozzle onto the machine, called a Fishman Dispenser, which is mechanical and therefore provides more accurate dispensing of fluids.

Translated into simpler terms, Mironov likens the printer to a hand holding a pencil.

“So imagine the pencil is the syringe, and hand is robotic hand.  That’s the printer.  And instead of ink, we have what we call bioink: cells and tissue.  That’s the principle of machine,” says Mironov.

“If Vladimir [Mironov] came back to me and said, ‘I need another one,’ I could do it… the basic concept is there.  It’s not brain surgery,” Kata says, about building a new machine.

Though bioprinters may not stem from a very complicated idea, researchers like Mironov are still working out how to make the organ-like tissue construct viable for transplant. 

“If you want to build the whole organ, then the most critical thing is… if there’s no blood profusion, then the organ will die,” says Mironov.

Making them bleed

To skirt this problem, Mironov and his colleagues have begun to build a vascular tree, or the network of arteries and veins that support the printed organ.

“If you inject something into the blood, you can see that every organ has very complicated branching vasculature,” says Mironov, who added that if one were to take a kidney for instance, there would be a system of arteries, veins, and capillaries that are integral making it function. 

Carleton University's Stefan Biljan demonstrates 3D printers
Carleton University's Stefan Biljan demonstrates one of the 3D printers at the school's Department of Mechanical and Aerospace Engineering

To date, Mironov and his associates have been able to create parts of the vascular tree with bioprinters.  However, there is still one more hurdle that must be overcome.

“If you want to transfer this organ, it must be solid and surgically attachable,” says Mironov, who added the organ-like tissue constructs have the consistency of mucus.  They are made of organic material, but are not strong enough for transfer.

However, Mironov still has some tricks up his sleeve. It is a new way of patching live tissue into the organ-like tissue construct that would make it thicker for transplant.

He says he hopes that with enough funding, bioprinters will one day be able replace organ donation.

For now, he and his associates continue to work on developing a bioprinted kidney.

“Basically… we put all of this together, and build kidney.  But when and how much, I don’t know.”

Frontpage photo courtesy of Brit. and fotos via Flickr

Related Links

Bioprinting 101

MUSC's bioprinting lab

How to make your own RepRap 3D printer

Catch up on the basics of bioprinting with this video



What about my HP?

The printer on your desk is also being used to print biological material. Tao Xu, an assistant professor of mechanical engineering at the University of Texas at El Paso, has been using ink jet printers to create human tissue. Cells are inserted where ink is normally inserted into the printer.

Mironov, however, is not convinced that ink jet printers are sophisticated enough to make viable organs.

"My feeling is that inkjet printer is ready for self-patterning, two-dimensional. But for three-dimensional I don't see any convincing papers yet," says Mironov, who explained that he was worried about what the laser in the ink jet printer does to the cell.

"The problem is laser can induce DNA damage in cells. They claim that there is not any DNA damage, but it's UV so I'm not sure that it's safe."


From Darwin to printers

This is a picture of RepRap's Darwin 3D printer

RepRap's Darwin model 3D printer can self-replicate 60 per cent of itself.

The 3D printers range from industrial sized ones that resemble large refrigerators to the smaller RepRap machine, which can fit on its own table.

Adrian Bowyer, a professor at the University of Bath in the United Kingdom, is the man behind RepRap, a self-replicating printer, which creates up to 60 per cent of the parts needed for the printer. The other 40 per cent is made up of readily available material that can be found for low prices. He says that since the instructions for re-printing RepRap are available on the Internet, RepRap has the potential to be modified into a bioprinter.

"It will start to diverge in quite the same way that the animal species changes, and so it's possible that we'll have more than one different type of RepRap." We tend to think of Darwinism as something that applies to animals and plants, but the fundamental rules of evolution by natural selection apply to anything that copies itself," says Bowyer, "But It doesn?t just have to apply to living things. The essence of self-copying is an important thing when it comes to Darwinian evolution."

However, Bowyer says that though RepRap has the capabilities of being modified to have different functions and have different sizes, it is not necessarily Darwinism.




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