Contact: Dan Gaffney
University of Sydney
A step closer to bio-printing transplantable tissues and organs:
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
“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
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
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
(see diagram below).
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.