Capillaries: A Mapping Geometrical Method using Organ 3D Printing

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Capillaries: A Mapping Geometrical Method using Organ 3D Printing

August 22, 2014 by 2012pharmaceutical

Capillaries: A Mapping Geometrical Method using Organ 3D Printing

Reporter: Aviva Lev-Ari, PhD, RN

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3D Printing at BWH

Major 3D Printed Organ Breakthrough: Vascular Networks Achieved

BY BRIAN KRASSENSTEIN · JUNE 30, 2014

Bio-printing promises to change the way the medical community deals with organ failure. Every year hundreds of thousands of people die because they could not receive an organ transplant soon enough. The demand for donor organs far exceeds the supply, leaving helpless patients in a state that no one should have to be left in… waiting to live.

We have already seen 3D printing create several types of human tissue, most notably liver tissue which is currently being used in drug toxicity testing. With that said, there is still one major hurdle to get us from the tiny sheets of 3D printed organ tissue, to that of entire 3D printed organs, which could one day be created by a patient’s own stem cells, and transplanted to save their life. That hurdle is the vascularisation of those organs. Every cell within a human organ, such as the liver, kidney or heart are within a hair’s width of a blood supply. This is an incredibly complex setup, one which up until now, researchers have found to be a nightmare to overcome when dealing with bioprinting. Without an adequate vascular network, the cells would be starved of oxygen, as well as a means to excrete waste, causing them to die and making the printed organs worthless.

Scientists from the Universities of Sydney, Harvard, Stanford and MIT have been working together to overcome these mountainous hurdles. Today, the University of Sydney made a groundbreaking announcement. The team of scientists from all four universities have figured out a technique, making such vascularisation possible within the 3D bioprinting process.

To achieve this, the researchers used an extremely advanced bioprinter to fabricate tiny fibers, all interconnected, which would represent the complex vascular structure of an organ. They coated the fibers with human endothelial cells, and then covered it with a protein based material, rich in cells. The cell infused material was then hardened with the application of light. Once hardened the researchers carefully removed the coated fibers, leaving behind an intricate network of tiny spaces throughout the hardened cell material. The human endothelial cells were left behind, along the tiny spaces created by the fibers, which after a week self organized into stable capillaries.

“While recreating little parts of tissues in the lab is something that we have already been able to do, the possibility of printing three-dimensional tissues with functional blood capillaries in the blink of an eye is a game changer,” said study lead author and University of Sydney researcher, Dr Luiz Bertassoni. “Of course, simplified regenerative materials have long been available, but true regeneration of complex and functional organs is what doctors really want and patients really need, and this is the objective of our work.”

The discovery of this technique should hopefully quicken the pace of bio-printing research, and lead to a time, in the not too distant future, when we can meet the demand of the growing need for organs transplants. We are still likely several years from such a time, but progress is certainly being made quite rapidly.

What do you think this technique means for the 3D printing of entire human organs? Let us know your opinion in the 3D printing organ forumthread at 3DPB.com.

[Source: University of Sydney]

SOURCE

http://3dprint.com/7729/3d-print-organs-vascular/

A step closer to bio-printing transplantable tissues and organs

2 July 2014

Researchers have made a giant leap towards the goal of ‘bio-printing’ transplantable tissues and organs for people affected by major diseases and trauma injuries, a new study reports.

Scientists from the Universities of Sydney, Harvard, Stanford and MIT have bio-printed artificial vascular networks mimicking the body’s circulatory system that are necessary for growing large complex tissues.

“Thousands of people die each year due to a lack of organs for transplantation,” says study lead author and University of Sydney researcher, Dr Luiz Bertassoni.

“Many more are subjected to the surgical removal of tissues and organs due to cancer, or they’re involved in accidents with large fractures and injuries.

“Imagine being able to walk into a hospital and have a full organ printed – or bio-printed, as we call it – with all the cells, proteins and blood vessels in the right place, simply by pushing the ‘print’ button in your computer screen.

“We are still far away from that, but our research is addressing exactly that. Our finding is an important new step towards achieving these goals.

“At the moment, we are pretty much printing ‘prototypes’ that, as we improve, will eventually be used to change the way we treat patients worldwide.”

The research challenge – networking cells with a blood supply

Cells need ready access to nutrients, oxygen and an effective ‘waste disposal’ system to sustain life. This is why ‘vascularisation’ – a functional transportation system – is central to the engineering of biological tissues and organs.

“One of the greatest challenges to the engineering of large tissues and organs is growing a network of blood vessels and capillaries,” says Dr Bertassoni.

“Cells die without an adequate blood supply because blood supplies oxygen that’s necessary for cells to grow and perform a range of functions in the body.”

“To illustrate the scale and complexity of the bio-engineering challenge we face, consider that every cell in the body is just a hair’s width from a supply of oxygenated blood.

“Replicating the complexity of these networks has been a stumbling block preventing tissue engineering from becoming a real world clinical application.”

But this is what researchers have now achieved.

What the researchers achieved

Using a high-tech ‘bio-printer’, the researchers fabricated a multitude of interconnected tiny fibres to serve as the mold for the artificial blood vessels.

They then covered the 3D printed structure with a cell-rich protein-based material, which was solidified by applying light to it. Lastly they removed the bio-printed fibres to leave behind a network of tiny channels coated with human endothelial cells, which self organised to form stable blood capillaries in less than a week.

The study reveals that the bioprinted vascular networks promoted significantly better cell survival, differentiation and proliferation compared to cells that received no nutrient supply.

Significance of the breakthrough

According to Dr Bertassoni, a major benefit of the new bio-printing technique is the ability to fabricate large three-dimensional micro-vascular channels capable of supporting life on the fly, with enough precision to match individual patients’ needs.

“While recreating little parts of tissues in the lab is something that we have already been able to do, the possibility of printing three-dimensional tissues with functional blood capillaries in the blink of an eye is a game changer,” he says.

“Of course, simplified regenerative materials have long been available, but true regeneration of complex and functional organs is what doctors really want and patients really need, and this is the objective of our work.

Watch bio-printing in action here.

Media enquiries: Dan Gaffney 0481 004 782, daniel.gaffney@sydney.edu.au

SOURCE

http://sydney.edu.au/news/84.html?newsstoryid=13715