Julius-Maximilians-Universität Würzburg (JMU)

3D Printing Living Cells

Innovative Materials for a Higher Quality of Life

In the field of biofabrication, the University of Würzburg is at the forefront of scientific development worldwide. The research field has a promising future and offers enormous potential for young scientists.

The new Würzburg Center of Polymers for Life is currently under construction on the university’s campus. In the future, research will be carried out there on polymers and processes for the 3D printing of artificial tissue models. Prof. Groll, you are one of the driving forces behind this project. “3D printing of artificial tissue models”—what should we understand by that term?

Prof. Groll: The focus of our research is regenerative materials. We are working on combining materials and cells in such a way that constructs are created that can mature into functional tissues—both outside and inside the body. This is done with special techniques that can be compared, casually put, to an inkjet printer. Or to writing a message in icing on a cake with the help of a piping bag—only smaller, automated, sterile, and using living cells. Accordingly, the term “biofabrication” refers to 3D printing to create tissue-like structures with cells.

And in the end, there’s a new organ on the table?

Prof. Groll: That is the idea in society, or rather the expectation. In fact, it’s not as simple as it sounds. Cells are not used to being printed, which means that we are always faced with new challenges.

Printing process of hierarchical constructs.
Prof. Jürgen Groll is one of the driving forces behind the new Center of Polymers for Life, which will open in 2024.

What specifically are you investigating?

Prof. Groll: Initially, we printed materials in a highly defined way and spent a long time analyzing the immune system—specifically, looking at the question of how we can use this artificial tissue to trigger the immune system to initiate healing processes, for example after a major injury. Now we have reached the stage where we can formulate cells into bio-inks using special materials. We can then print them and arrange them spatially to create tissue-analogous structures. We started with cartilage tissue. Currently, together with our partners at the Universities of Bayreuth and Erlangen, we are exploring cartilage tissue, muscles and heart muscles, the kidney, the central nervous system, and strategies for printing vascular structures as part of the Collaborative Research Center TRR225 "From the fundamentals of biofabrication to functional tissue models".

What approach are you taking here?

Prof. Groll: First of all, it has to be said: We are not primarily doing clinical patient-oriented research. We are more interested in creating an in vitro model in which the cells behave naturally. If, for example, we succeed in getting neurons to form synapses, we will have a model for the central nervous system that can be used to study disease progression in more detail. Ideally, this could then open up new approaches that could lead to better therapies.

Electron micrograph of a cell-populated construct being developed for artificial blood vessel replacement.
Electron micrograph of a cell (colored red) interacting with biomaterial fibers. The fibers are only a few micrometers in diameter.

Where are the difficulties?

Prof. Groll: We are now good at printing living cells. But that doesn’t mean we can print adult tissue. If you spatially arrange the different cell types needed for a particular tissue, they have to form certain structures, make connections, move close together. After printing, however, the cells first have to orient themselves and find each other. They have to mature into a functional compound. This happens slowly, and it is challenging to spatio-temporally orchestrate this process so that it goes in the right direction.

In layperson’s terms, it sounds as if tailor-made organ replacements will soon be available from the printer.

Prof. Groll: Unfortunately, that’s not how it works. There will be simpler tissues for which this will be possible more quickly—skin, for example. For complex organs, it will certainly take longer. That’s why we now have to investigate exactly how the tissue in question is created in the living organism. For example, are there precursors that have to be brought into contact with each other for the tissue to develop? This is where biology comes into play—which, by the way, is a trend that is gaining momentum in the field of biofabrication. And we see: this is where it gets interesting, but at the same time extremely complex. So we are still learning an enormous amount. Nevertheless, I’m convinced that the field has huge potential. There will be tremendous successes. The technology will get that far and end up in humans.

Printing process of hierarchical constructs.
Addition of culture medium for in vitro culture of biomaterials.

What role does the University of Würzburg play in the field of biofabrication?

Prof. Groll: Without exaggerating, one can say that Würzburg is an internationally visible location for this field. There are only a few comparable locations worldwide. And in association with Bayreuth and Erlangen, Würzburg has a unique structure and potential. We have worked hard to achieve this position in recent years through ground-breaking publications and papers, through our work in the Collaborative Research Center TRR225, through our involvement in international societies, and through the organization of international conferences. So we are a recognized hub in this field.

What do you expect from the new “Center of Polymers for Life”?

Prof. Groll: The building is being constructed in the immediate vicinity of a whole range of departments with which we work closely. Biofabrication works with printing processes—so it needs hardware and software components. For this, we need specialists from computer science and robotics. Cells are involved, so we need biologists with their expertise. Materials science and chemistry are needed when it comes to the right carrier material. Biologically active molecules and active ingredients are involved—so pharmaceutical technology is important. Then the development is translated into an application—that’s where we need medicine. In short, there are many different traditional disciplines that need to cooperate in biofabrication. The new building is designed to bring these disciplines together. So I expect a lot of synergies. It should not be forgotten that the building will also mean a significant increase in personnel at the University of Würzburg.

The Center of Polymers for Life

The Center of Polymers for Life (CPL) is currently under construction on the campus of the University of Würzburg. The 23-million-euro building will provide a dedicated home for research on polymers for applications in the life sciences, with a focus on biofabrication. With a floor space of around 1,600 square meters that will be equipped for the planned interdisciplinary research, the center will additionally be outfitted with the latest large-scale equipment, at an additional cost of four million euros. Research there will focus on polymers for applications in the life sciences, and in particular on biofabrication. The automated simultaneous processing of cells and materials into hierarchically structured cell-material constructs with the aim of producing biologically functional tissue structures requires the integration of many traditionally separate disciplines. Biofabrication is therefore a distinctly interdisciplinary research field that employs principles from materials science, chemistry, biology, physics, medicine, and engineering in combination for successful research. In the CPL, all these different areas of expertise will be brought together under the same roof for the first time.

Speaking of additional personnel, ”what qualities would a young scientist who wants to join your team need to have?

Prof. Groll: Whether chemistry, biology, materials science, pharmacy, or even computer science and engineering: if you come from one of these disciplines and are genuinely interested in thinking outside the box, if you enjoy collaborating with other disciplines and tackling new things, you’ve come to the right place. Biofabrication is an extremely future-proof field where a lot will happen and where many new jobs will also be created in the coming years—especially in research. However, you have to be open-minded and not be afraid of tackling something completely new. And a good dose of enthusiasm never hurts, of course.

A biofabricated construct.
Close-up of a biofabricated construct.

Is Würzburg a good place to live?

Prof. Groll: Würzburg has a lot to offer. The quality of life is high, and the city is an ideal size, so there’s an attractive city life here without the drawbacks that many big cities have. The landscape is also very beautiful—I really like it here.

The Institute for Functional Materials and Biofabrication

In 2020, several chairs at the University of Würzburg combined forces to found the Institute for Functional Materials and Biofabrication (IFB). This new institute aims to intensify interdisciplinary and interfaculty cooperation in the field of functional materials and biofabrication and to promote the joint use of dedicated research and service facilities. The Chair of Functional Materials in Medicine and Dentistry (Prof. Dr. Jürgen Groll) and the Chair of Chemical Technology of Materials Synthesis (Prof. Dr. Gerhard Sextl) are both currently involved. They will be joined by the newly created Chair of Macromolecular Chemistry, which is currently being filled. Together, the three chairs form the collegial leadership of the IFB.

The IFB will work closely with the Fraunhofer Translational Center for Regenerative Therapies, which is also located in Würzburg, and the associated Chair of Tissue Engineering at the University Hospital of Würzburg. This chair will be filled in the near future, with the involvement of the IFB. Currently, the Translational Center is being renovated at a cost of around 23 million euros and equipped with state-of-the-art research infrastructure. The research there will focus on regenerative therapies, new cell-based tissue models and test systems, scalable production processes, and biological vascularized implants through to prototypes.

Finally, on your chair’s homepage one can read the mission statement “Higher quality of life through innovative materials.” What exactly does that mean?

Prof. Groll: I’ve been at the University of Würzburg for just over ten years now. And that was the first thing we thought about: What is our core mission? After all, we are essentially doing basic research. But it was also clear to us that our actual goal is not just to achieve and publish research results. Rather, our work should sooner or later benefit people and improve their lives. So the mission statement describes the big vision behind everything.

Thank you very much.

For more information about biofabrication at the University of Würzburg, contact Prof. Jürgen Groll at the Chair of Functional Materials in Medicine and Dentistry!

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