Meet Prof. Erik Reimhult from BOKU, Vienna

Tuesday, August 23, 2011

Erik Reimhult is a Professor in Nanobiotechnology for Supramolecular materials at BOKU, Department of Nanobiotechnology, in Vienna. Read about his thoughts on his research below or meet him in Bensheim, Germany, this autumn.

The title of your talk for the QCM-D Scientific World Tour 2011 is QCM-D to reveal processes at biomembrane surfaces of relevance for drug delivery. Could you describe how this is related to your research in general and write a few sentences about your project at the moment?

"The QCM-D has been with me as a tool to study surface-related assembly processes for almost as long as I have been doing research. And it has become the favorite tool for doing so of almost every student that I have worked with as well, although they typically have another set of techniques as their main techniques to address their respective research question(s)" Professor Reimhult says.

"Thus, the QCM-D in one way or another is used as a characterization tool in almost every research project I have had. Typically we use it to get a first feeling for how molecules interact with a designed interface, what kind geometry they assemble into, hydration and conformational changes during the assembly or further interaction, i.e. the kind of data that the QCM-D has become famous to produce. I think that once you get used to the data from the QCM-D it provides you with a very intuitive way to “get to know your system”. While often not producing the quantitative data on the nano-scale that I need to answer me and my coworkers’ final questions, it almost always provides us with the crucial first steps and a few important points along the way to reach that understanding.

The projects I am likely to relate to during my talk concern the interaction of lipopolymer systems with solid surfaces and the hydration of polymer brushes under changing solvent conditions. The first has been an area in itself in my group as we tried to understand the mechanical effects of associated polymers on models of biological membranes. The second area is of fundamental importance to understand how designed, functional, core-shell nanoparticles interact with liquid-liquid interfaces, which beyond its fundamental importance will have implications on how we design nanoparticles for materials, drug delivery and imaging applications".

Why is this type of research interesting to you personally?

"I have a very physicist fascination for nature. That is, while I in contrast to all my scientific mentors cannot for my life understand what is fun about fishing, hunting or knowing a lot about gardening, I am fascinated that “engineering” choices in biology are so different to what we got taught in engineering school. It took many years to understand what it was that fascinated me exactly, but as I understand (myself) now it is that when we as humans think of structure and solidity, nature “thinks” of fluidity and remodeling.

While we want to stick something tight, nail it down, to know that it is where it is supposed to be, nature keeps interactions weak, make things fluid and responsive, allowing adaption to the environment which allows a material to have many functions. Biological membranes, which I started to work with due to their application in bio-sensing, are a prime example of this.

Nowadays, I am more trying to imagine how I can bridge the nature-engineer gap in materials science. That these concepts might be generic rather than peculiarities and a new paradigm for us to think in is what fascinates me. I try with my co-workers to design concepts and building blocks that allow us to work in a fluid manner, with higher robustness and the functionality that we want for our specific applications. But we have only started, so what we are studying now are just the fundamentals of selected such weak interactions, probing the soft matter physics aspects of such systems while in parallel trying to design new systems. Hopefully, also all the applied aspects are there, but on the way we have already learnt many things that has made it possible for us to create new drug delivery vehicles and biomedical imaging probes for example. I really believe this is where I am still a physicist, that the kind of knowledge that we create is generic. I will try to show a glimpse of these things that excite me as well during my talk, even if they are not directly related to QCM-D. But this is what I use our QCM-D results for, to understand interfacial aspects of these systems".

How does your research fit into a bigger context?

"I think I half-answered that to the previous questions" Professor Reimhult says continuing:
"But if I try to be just a little bit more succinct: My research is part of an old field of research in physics dealing with weak multiple interactions and liquid interfaces. Thanks to the advent of new or improved characterization tools developed for nano science and the converging of biology, chemistry and physics into a new bioinspired materials science, soft matter physics has become an increasingly important discipline.

As with solid state physics the devil is in the surface and a lot of the most interesting interactions occur there. In soft matter physics we don’t speak of surfaces but of interfaces which are “fuzzier” and therefore contain even more of a devil. I aspire to be one of the young scientists who work to develop this area of soft matter (liquid) interfaces by combining the converging disciplines. If I were a better physicist I would probably focus more on theory development and deep understanding, but knowing my limitations I am instead trying to realize bio-inspired concepts and develop the experimental approaches to study them thoroughly.

If you ask me, this area of research is what will eventually lead to the creation of most of those science fiction toys you see in movies. The future society will have an organic flavor to everything related to our materials, and materials are everything that is not confined to the virtual world. However, biology cannot give us engineering directly, but soft matter physics can give us, for lack of a better word, “organic engineering” to the benefit of health, medicine as well as new materials for the gadgets people like me crave".

When did you first get in contact with QCM-D?

"I was one of the few unlucky (!) persons who encountered QCM-D before Q-Sense sent their products to the market. When I realized that the first idea I wanted to realize for my PhD was physically unsound (a kinder way of saying that it was completely uninformed, against nature and borderline insane) I humbled myself and checked what people were doing in Prof. Bengt Kasemo’s lab where I did my PhD and what all the fuzz was about the topics that he tried to pitch to me.

And there were all these toys around with big nice shiny crystals, a very intense and interesting guy called Fredrik Höök running around and some students throwing lipids on these crystals getting interesting data curves. After one year I had thrown away the plan for my first project and was working on home-built QCM-D setups to understand better the interaction of liposomes with solid substrates and learning what I could from Bengt and Fredrik about this kind of systems and instrument driven research.

Increasingly I was working with combining QCM-D with optical evanescent measurements and combining that with modeling, typically applied to liposome adsorption. So, due to that perhaps too early encounter with the QCM-D there are more than a few students who have heard me introduce the Q-Sense E4 with words similar to 'You will never know how it is like to REALLY measure QCM if you use this instrument. It is no sport if you can get a baseline right away and do not have to learn how to tell an artifact from a real result'. What do you know…I'm a grumpy old grampa at 36…," Professor Erik Reihult jokes.