Welcome to the Rädler Group
We are a soft condensed matter group studying self-assembly and dynamics of macromolecules and lipid membranes and the spatio-temporal self-organization of living cells (active matter). In particular we are interested in the structure and function of lipid-DNA complexes and the response of living cells to controlled cues exerted by functionalized surfaces, hydrogels and artificial nano-agents. Doing so we strive to discover physical principles that allow living systems to fullfill function and to improve technological applications such as cell based assays and synthetic gene delivery.
Collective cell migration is a key element in morphogenesis, cancer formation and wound healing. The multicellular dynamics of epithelial cell layers were studied in experiment and theory over the last years. Yet little is known about cell patches of finite size that should lead over from single cell behavior to collective motion. Here we study the migration and proliferation of small assemblies of epithelial cells
In gene and siRNA based therapy, therapeutic benefits rely on the efficient transfer of foreign nucleic acids into cells. We investigate synthetic complexes capable of readily carrying nucleic acid across the cell membrane. The self-assembly, size and structure of lipid- and polycation-DNA complexes, known respectively as lipoplexes and polyplexes, are studied. We also endeavor to quantify and model transfection at the single cell level using GFP reporter and single cell time-lapse microscopy.
We fabricate artificially designed micro-environments to culture and probe living cells. Arrays of defined cavities provide standardized geometric boundaries for individual cells or groups of cells. We study single cell gene expression, cell migration and apoptotic events with precise spatio-temporal control. To this end we develop biofabrication techniques, including photo-lithography, hot-embossing, electroplating, soft lithography, 3D printing and microcontact printing, to create two-dimensional (2D) and three-dimensional (3D) pattern, cavities and channels made of biocompatible materials like PDMS, COC, hydrogels and proteins. The 3D microenvironments allow for long-term observation of growth and function of individual living cells, interacting groups of cells and organoids.
We are interested in the kinetics of cellular responses, in particular in gene expression after transfection and event cascades in cytotoxicity. Using live cell imaging on single cell arrays (LISCA) time courses from individual cells are monitored and analyzed based on mathematical models. Cellular microarrays help to resolve cellular heterogeneity, a hallmark of complex biological systems dominated by intrinsic fluctuations.
Biopolymers have unique properties with respect to their self-assembly, conformational dynamics, transport and interactions with interfaces. Fluorescently labeled biopolymers and proteins can be studied by Quantitative Fluorescence Microscopy (QFM) and Fluorescence Correlations Spectroscopy (FCS).
Supported membranes are versatile biomimetic interfaces. We study the structure and dynamics of supported membranes on various solid supports in collaboration with the group of Bert Nickel. The control of fluidity, spacing and lateral organisation is a current research challenge.