Molecular Force Sensors
In biological systems force sensors are mostly proteins. These proteins react to the mechanical influence with a conformational change that triggers a biochemical signalling cascade. Our goal is to understand the underlying molecular mechanisms and utilize them for the design of artificial force sensors with novel properties. Our artificial force sensors possess an optical readout signal that provides information about the current conformation of the sensor. These artificial sensors are not necessarily proteins, but can also be composed of other biological or even synthetic molecules.
Forces in Polymeric Networks
We are using these force sensors for investigating mechanical processes in polymeric materials. Currently used techniques can only report on bulk mechanical properties such as the elastic modulus. They often fail to provide information about the molecular forces that define the material properties. In contrast, our force sensors provide information about the forces acting along individual polymer chains or experienced by a single crosslink. Currently the main focus is on biological and biomimetic materials that require defined mechanical properties for cell growth and differentiation. Knowledge of mechanical cell-material interactions is essential for designing synthetic extracellular matrix mimics required in tissue engineering and regenerative medicine.
Integrating Force with Fluorescence Detection
The development and analysis of molecular force sensors requires characterization techniques that are able to establish the relationship between the applied force and the generated fluorescence signal. We are using single molecule force spectroscopy combined with single molecule fluorescence detection for calibrating this relationship. We are further developing methods to combine single molecule fluorescence detection with bulk mechanical testing techniques. This allows us to follow the fate of every individual force sensor in a polymeric material. In this way we obtain unique information about the local force distribution throughout the material. This knowledge does not only provide input for the development of novel cell culture materials, but can also guide the design of novel materials with self-reporting or self-healing properties.