Researchers believe that we may be one step closer to being able
to use 3D-printed tissue in organ transplant surgery.
Over the last year or so we’ve seen a remarkable number of
situations in which 3D printing technology has been deployed in the
medical world, including the bioprinting of liver tissue. One problem that has
yet to be overcome though is the vascularisation of printed organs
— that is, making sure that the cells within any tissue are
connected to the blood supply so that the organs are capable of
surviving on a long-term basis.
Researchers from Harvard, MIT, Stanford and the University of
Sydney have been working together to try to find a solution that
will allow them to overcome this hurdle and eventually create
organs grown from patient stem cells that can be successfully
transplanted into their own bodies.
The University of Sydney has now announced that the research has led to the bioprinting
of artificial vascular networks that mimic those found within the
human body’s circulatory system, bringing hope that eventually
physicians will be able to print fully working organs
The deficit of transplantable organs causes thousands of deaths
that could otherwise be averted every year, and others are
subjected to invasive surgery involving the removal of tissue or
entire organs due to cancer or injury.
“Imagine being able to walk into a hospital and have a full
organ printed — or bioprinted, 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,” says
University of Sydney researcher, Luiz Bertassoni. “We are still far
away from that, but our research is addressing exactly that. Our
finding is an important new step towards achieving these
Currently the research teams are printing prototype systems and
focussing on the challenge of growing an adequate network of blood
vessels and capillaries capable of servicing large organs.
“To illustrate the scale and complexity of the bioengineering
challenge we face, consider that every cell in the body is just a
hair’s width from a supply of oxygenated blood,” says Bertassoni.
“Replicating the complexity of these networks has been a stumbling
block preventing tissue engineering from becoming a real world
Already though, the team has managed to fabricate a multitude of
interconnected fibres using a bio-printer. These fibres serve as a
mould for the artificial blood vessels, and the printed structure
is completely covered in a cell-rich protein-based material. This
is solidified using light before the printed fibres are removed.
What is left behind is a network of tiny channels covered with
endothelial cells — the cells that line the interior surface of
all blood and lymphatic vessels in the human body.
Within a week, the cells had self-organised to form stable blood
capillaries and a subsequent study has shown that these bioprinted
networks promote significantly better cell survival,
differentiation and proliferation than had previously been
“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,” 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.”