Dr. Trappmann, what scientific topic are you working on right now?
We’re interested in angiogenesis – in other words, how new blood vessels form from existing ones. Endothelial cells play an important role in this process. They line the interior blood vessel surface. We study how endothelial cells interact with the surrounding tissue – with the so-called extracellular matrix. Specifically, we investigate which parameters are governing the process of endothelial cell migration and the formation of new vessels. It’s actually not at all easy to find a good tissue model for our experiments, and so we have developed a synthetic material system in which we can control all matrix parameters individually. The problem with natural models is: when you alter one property, you simultaneously alter another one as well. For our artificial extracellular matrix we chose a sugar molecule which is protein- and cell-resistant as the base material. This means that we can systematically change the concentration and the type of adhesive ligands, i.e. the proteins which cause the cells to adhere to the matrix and which, among other things, pass on signals for migration or growth. In addition, we can influence not only the mechanical properties of the matrix, but also how fast a cell can cleave the matrix in order to migrate. One day, when we understand the roles of all environmental parameters, tailored artificial tissues could be produced for implants. Our specialist area – so-called biomedical engineering – is not very widespread in Germany. In the United States, however, it forms the basis of many research projects, in which chemists, biologists, physicists and engineers develop new biological test models or techniques. Looking beyond your own particular field provides entirely new research opportunities – such as our 3D tissue model for angiogenesis.
What characterizes you personally as a scientist?
In my team, I want every group member to take on responsibility and contribute to scientific discussions. I hope that this way I’ll be training my PhD students and postdocs to become good scientists. I have always had excellent mentors myself who demanded a lot of me but who always encouraged me to form and express my own scientific opinions. I believe that’s a key requirement for good science. Young scientists bring fresh ideas into research projects.
What is your greatest aim as a scientist?
One day my career will end, but I would like to see the continuation of ideas stemming from my research. That’s another reason why training of junior researchers is so important. Additionally, I am hoping that one day my research findings can be applied in the field of medicine. I have the vision that my work will contribute to progress in tissue engineering, so that doctors are able to produce and implant artificial tissues based on the material parameters we identified. I don’t want to do research just for its own sake and produce one or another molecule just because it’s possible in principle. That’s certainly important, but I’m much more interested in practical applications.
What’s your favourite toy for research – and what is it able to do?
We have a new spinning disc microscope which works very fast and produces a new image every second. It enables us to watch endothelial cell migration in 3D.
Can you remember your happiest moment as a scientist?
When I was a post-doc I developed my angiogenesis model on the basis of a new kind of hydrogel. For many months, though, endothelial cells simply would not migrate collectively into our hydrogel. It finally worked one year later. My current research builds on this success.
And what was your biggest frustration?
It’s of course frustrating when an experiment doesn’t work. You have to be careful, though, that you don’t give up too easily just because the experiment might not confirm your hypothesis. Experiments which fail for technical reasons frustrate me the most – especially when we don’t know what went wrong. We work very focused for several days on the production of our tissue models. At the beginning we produced a lot of deficient samples because something had gone wrong somewhere along the line. It took six months for our models to be 90 percent usable.
Which scientific phenomenon still regularly fascinates you today?
What fascinates me is the interplay of cellular processes. We can explain individual aspects, processes or functions of cells and molecules, but we’re only just beginning to understand how human beings function in their entirety.
What big scientific question would you like to have an answer to?
Which parameters drive angiogenesis? You have to pursue a variety of approaches to get a full understanding of this complex process. Our approach tends to be more materials science-based, while other research groups study the topic from a different angle. Angiogenesis research is, at heart, a biological subject. The aim of our models is to help provide suitable tools for biological questions. That’s the advantage of the interdisciplinary approach: together, we can understand the big picture.
How much artistry, creativity and craftsmanship is there in your scientific work?
Before we can get going with any biological experiment, we have to fabricate our tissue models. This step involves a lot of precise work on very small scales. We produce our model platform using engineered molds in combination with our newly developed hydrogel material. The platform is around two centimeters long and consists of artificial channels on the micrometer scale. We have to assemble the individual parts, and, depending on the experiment, coat the channels with varying biologically active substances. The whole process requires a high degree of precision, so you need to be good with your hands.