Development of strategies for the characterization of biological processes and soft-matter structures by (cryo-)TEM

The development of transmission electron microscopy (TEM), and cryo-TEM in particular, has had a major impact on science, as it enables the visualization of structures down to the molecular level, as well as, the ultrastructural imaging of biological samples. This thesis first presents various functional staining techniques for TEM analysis that can be used to visualize intracellular metabolic processes. One of the presented concepts is then taken as basis to develop sensor particles for the detection of reactive oxygen species (ROS) by TEM analysis. This approach has the advantage of being less cytotoxic and more stable compared to the original technique. In the third chapter, the structural analysis of drug delivery systems depending on the preparation conditions and the visualization of the decomposition mechanisms highlights the importance of cryo-TEM analysis to develop targeted delivery systems. Finally, it could be demonstrated that cryo-TEM analysis can be applied beyond aqueous systems and can also be used for buffer systems, as well as, for the analysis of samples in organic solvents.