Research

The Center for Biophysics is concerned with the theoretical and experimental modeling of non-equilibrium processes in biological systems and cells. The aim of this modeling is to uncover and understand the physical principles that arise from the interaction of many molecular and cellular actors and thus give rise to the many different forms and functions of living matter. Prominent examples include active processes that occur far from thermodynamic equilibrium, such as intracellular transport and signalling processes or cell migration and polarization. Over the last three decades, studies at the molecular level have revealed that these physiological phenomena are regulated by complex networks of molecular interactions, but also that their complexity usually makes direct or intuitive access impossible. Dynamic processes are particularly interesting in this context, since in systems consisting of many components there is usually no simple connection between the structure of the process and the properties of the individual elements. Accordingly, the search for a deeper understanding of such processes is currently attracting enormous attention and offers great potential for the future.

Recently, mathematical approaches to gaining such an understanding have primarily taken two directions. The first involves the quantitative analysis of all elements of a network and the subsequent simulation of all interactions by means of numerical calculations. This strategy is particularly effective in relatively simple systems such as metabolic networks of individual cells and is mainly pursued in the field of systems biology. For more complex systems, however, in which temporal and spatial parameters also play an important role, this method can no longer be used to make meaningful predictions. A second method, simplified mathematical models that omit the details of the systems, can be used here to more effectively describe the nature of complex systems. An impressive example of such a model is the reaction-diffusion model proposed by Alan Turing. A simplified model can be very helpful in making predictions and, in combination with experiments, can lead to a general understanding of selected problems.

From a physics point of view, the consideration of the relevant non-equilibrium processes goes far beyond the conventional analysis of the aspects of nonlinear or collective processes usually applied in systems of soft condensed matter, such as complex fluids, colloids and polymers, because cellular processes dissipate energy in a highly organized way and are internally driven. The long-term goal of our research is therefore to develop new theoretical models and experiments that lead to a similarly detailed description of cellular processes as already exists for dynamic systems of non-living matter.

From the large number of non-equilibrium processes that occur in cellular systems, the center focuses primarily on self-organization, transport, aggregation, and molecular cooperativity. Both spatial and temporal analysis of phenomena occurring in many-particle systems play a role. This analysis combines the observation and quantification of interactions between proteins, organelles, and cells and includes the subsequent theoretical analysis using the concepts of statistical physics and bioinformatics. The combination of these results then takes place at the Center for Biophysics and aims to incorporate these interactions into the description of active processes by identifying individual molecular and cellular factors. Examples include local reactions of cells, cytoskeletal dynamics, endocytosis, exocytosis, cell polarization, and migration or the formation of bacterial biofilms.

The main distinguishing features of the Center for Biophysics are

1. the thematic focus on the development of theoretical models for experiments, which are also carried out at the center itself
2. the close cooperation between the disciplines of biosciences and physics, which is reflected in the strong link between research projects
3.  the medical relevance of the systems investigated, such as T cells, cadriomyocytes, erythrocytes, Staphylococcus aureus, DNA methylation, A/B toxins and biofilms on teeth.

The center is characterized by the underlying methodology imaging techniques such as Flurorescence Deconvolution Video Imaging, TIRF microscopy, confocal and mutliphoton microscopy, optical tweezers, and atomic force microscopy but also by the theoretical and numerical techniques specifically adapted to active systems far from equilibrium.

The quantitative analysis of non-equilibrium processes that take place in many-particle systems falls within the field of physics. Many scientists have already recognized the urgent need to apply existing and develop new physical methods to explain cellular systems. However, in order to guarantee the success of such an approach, the expertise of all disciplines involved must be brought together efficiently. Here, the Center for Biophysics offers a unique research environment.