Made to order 3D printed hearts and other organs for transplants are to be produced from the same protein used in ‘trout pout’ lip boosting procedures.
Boffins have developed a technique to mass produce anatomical structures – from collagen.
The protein is a key component of the extracellular matrix in a variety of tissues – and is widely used in engineering research.
But its use in biomedicine has been hindered by technological limitations including poor tissue fidelity and low print resolutions – until now.
The researchers have developed a method dubbed ‘FRESH’ (freeform reversible embedding of suspended hydrogels).
It’s a new way of 3D printing complex anatomical structures out of collagen – the primary building block in many human tissues.
They made cardiac structures and tissues that closely mimic the form and function of those in the human heart.
It uses rapid changes in acidity to cause extruded collagen to solidify with precise control.
Dr Andrew Lee, a biomedical engineer, said: “The method can create complex structural and functional tissue architectures that can be further embedded with living cells or complex vasculature at printing resolutions up to 10 micrometers.”
His team used this approach to create human heart parts entirely from collagen and human cells including cardiac tissue, contractile ventricles – and even a newborn’s heart.
Bioprinted hearts accurately reproduced anatomical structures that mirrored those found on patients’ MRI (magnetic resonance imaging) scans.
Components printed with human cardiac muscle cells achieved advanced contractile functionality, they say.
Dr Lee, of Carnegie Mellon University in the US, said: “Collagen is the primary component of the extracellular matrix in the human body.
“It has proved challenging to fabricate collagen scaffolds capable of replicating the structure and function of tissues and organs.
“We present a method to 3D-bioprint collagen using freeform reversible embedding of suspended hydrogels (FRESH) to engineer components of the human heart at various scales, from capillaries to the full organ.”
“We found that FRESH 3D-bioprinted hearts accurately reproduce patient-specific anatomical structure as determined by micro–computed tomography.”
The support bed is made up of a thermally reversible, viscous gelatin slurry that offers a flexible support for the printing nozzle.
The nozzle can easily penetrate the support bed without encountering resistance and holds the printed hydrogel structure in place without it collapsing.
After printing, the hydrogel is released from the support simply by heating to 37°C, which melts the support.
The result was successfully printed parts of the human heart from collagen hydrogels at a resolution of 20 mm, which exceeds the resolution of 100 to 500 mm achieved with other techniques.
Dr Lee added: “We have used the human heart for proof of concept; however, FRESH printing of collagen is a platform that can build advanced tissue scaffolds for a wide range of organ systems.
“There are still many challenges to overcome, such as generating the billions of cells required to 3D-bioprint large tissues, achieving manufacturing scale, and creating a regulatory process for clinical translation.
“Although the 3D bioprinting of a fully functional organ is yet to be achieved, we now have the ability to build constructs that start to recapitulate the structural, mechanical, and biological properties of native tissues.”
Dr Queeny Dasgupta, of Tufts University in the US who was not involved in the study, described it having “unprecedented promise” for the future.
Dr Dasgupta said despite the challenges it brings the “prospect of creating functional organs and tissues from computer-generated models, thereby bringing on-demand organ printing closer to reality.”