Nov 11, 2016
Using a modified Ultimaker 2+, plus a specially developed bio-ink, students from the Technical University of Munich believe they’ve found the key to 3D printing replacement human organs. Read on to discover more about their remarkable achievement.
What is bioprinting?
3D printing opens amazing possibilities in the field of healthcare. With the aid of 3D printers, scientists are now able to fabricate tissue shaped from real human cells. The potential is incredible – and the technology could soon be used to create 3D printed human organs.
If this is possible, it could address a serious global problem. In 2015, 120,000 U.S. patients were waiting for a graft organ. Only a quarter of those received one in time. An average of 22 patients in the U.S. die each day due to organ donor shortage. The cost of supplying and transporting organs is huge, with costs per patient rising continually. For example, it’s anticipated that the cost of a liver lobe transplant could be as high as $2 million by 2020.
If medical establishments could print organs instead, costs could be slashed and numbers of deaths dramatically reduced.
An easy process?
As you might imagine, printing cells is no mean feat. Human cells do not have printer-friendly material qualities, so scientists have to use bio-inks; substances that can be mixed with cells to make them printable. However, up until recently, these bio-inks have presented various challenges, and a particular issue is the temporary scaffolds required to support organic structures.
Finding the solution
The students at the Ludwig-Maximilian University of Munich and the Technical University of Munich believe that their new 3D bioprinting ink eradicates many of the issues associated with conventional bioprinting techniques. By using biotin and streptavidin, their biotINK acts as a ‘molecular superglue’, binding the biotin to the receptors and locking cells into position whilst printing. This ensures a far more precise print – which is vital when manufacturing replacement organs.
This new bio-ink speeds the process up too, enabling the formation of ‘three-dimensional intercellular contacts and physiological microenvironments.’
Team member Luisa Krumwiede explains further. “All of these things cross-link with each other because streptavidin has binding sites for biotin, and is capable of binding biotin to our receptor. They should then polymerize and form a 3D structure.” Unlike previous bio-inks, it doesn’t require a scaffold and has the necessary properties to create complex tissues and multiple cell types.
The IGEM challenge
The students entered their research into the iGEM challenge, an annual contest for biologist, biochemists and bioengineers. To develop biotINK, they hacked their Ultimaker 2+ printer, replacing the extruder with a 3D printed syringe pump. This replacement pump was programmed to extrude cells to millimeter-level precision. You can find out how to do it here.
How does it work?
The team provides a step-by-step guide to how it works:
- The existing extruder outlet is used to power and control the self-designed syringe pump.
- The pump is connected to the new print head via a capillary, with an adapter for exchangeable cannula.
- A build plate adapter must be used to cope with liquids, plus various cell culture containers. The firmware must also be adapted.
- An optimized user interface is required for the slicing software, as containers are being used and collision is an issue. Machine codes also need to be corrected for difficult-to-reach areas.
To improve quality control, RGB LEDs and a touch-based user interface will be included in the future. Webcams and wavelength-specific image analysis will also be used to improve optical control.
The Ultimaker 2+ is ideal for the task, as it can be easily modified to be compatible with biotINK, and it is far more cost-effective than a specialist 3D bioprinter. Researchers believe that the modification techniques could be adopted by any lab.
What are the implications?
The new technology offers huge potential for doctors and researchers. It will enable them to print nearly all parts independently, with the exception of certain metal components and wires. The cost is greatly reduced, which means more people will have access to the technology. It’s also simple to modify an existing 3D printer without extensive mechanical knowledge.
With this technology, more laboratories can experiment with 3D bioprinting, accelerating R&D in the field and improving healthcare across the world.