@article{WeiglBlumSanchoetal.2022,
  author    = {Weigl, Franziska and Blum, Carina and Sancho, Ana and Groll, J{\"u}rgen},
  title     = {Correlative Analysis of Intra- Versus Extracellular Cell Detachment Events via the Alignment of Optical Imaging and Detachment Force Quantification},
  series = {Advanced Materials Technologies},
  volume    = {7},
  journal   = {Advanced Materials Technologies},
  number    = {11},
  issn      = {2365-709X},
  doi       = {10.1002/admt.202200195},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-318544},
  year      = {2022},
  abstract  = {In recent decades, hybrid characterization systems have become pillars in the study of cellular biomechanics. Especially, Atomic Force Microscopy (AFM) is combined with a variety of optical microscopy techniques to discover new aspects of cell adhesion. AFM, however, is limited to the early-stage of cell adhesion, so that the forces of mature cell contacts cannot be addressed. Even though the invention of Fluidic Force Microscopy (FluidFM) overcomes these limitations by combining the precise force-control of AFM with microfluidics, the correlative investigation of detachment forces arising from spread mammalian cells has been barely achieved. Here, a novel multifunctional device integrating Fluorescence Microscopy (FL) into FluidFM technology (FL-FluidFM) is introduced, enabling real-time optical tracking of entire cell detachment processes in parallel to the undisturbed acquisition of force-distance curves. This setup, thus, allows for entailing two pieces of information at once. As proof-of-principle experiment, this method is applied to fluorescently labeled rat embryonic fibroblast (REF52) cells, demonstrating a precise matching between identified force-jumps and visualized cellular unbinding steps. This study, thus, presents a novel characterization tool for the correlated evaluation of mature cell adhesion, which has great relevance, for instance, in the development of biomaterials or the fight against diseases such as cancer.},
  language  = {en}
}
@phdthesis{Weigl2023,
  author    = {Weigl, Franziska},
  title     = {Correlation of FluidFM® Technology and Fluorescence Microscopy for the Visualization of Cellular Detachment Steps},
  doi       = {10.25972/OPUS-29876},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-298763},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {This thesis aimed the development of a correlated device which combines FluidFM® with Fluorescence Microscopy (FL) (FL-FluidFM®) and enables the simultaneous quantification of adhesion forces and fluorescent visualization of mature cells. The implementation of a PIFOC was crucial to achieve a high-resolution as well as a stable but dynamic focus level. The functionality of SCFS after hardware modification was verified by comparing two force-curves, both showing the typical force progression and measured with the optimized and conventional hardware, respectively. Then, the integration of FL was examined by detaching fluorescently labeled REF52 cells. The fluorescence illumination of the cytoskeleton showed the expected characteristic force profile and no evidence of interference effects. Afterwards a corresponding correlative data analysis was addressed including manual force step fitting, the identification of visualized cellular unbinding, and a time-dependent correlation. This procedure revealed a link between the area of cytoskeletal unbinding and force-jumps. This was followed by a comparison of the detachment characteristics of intercellular connected HUVECs and individual REF52 cells. HUVECs showed maximum detachment forces in the same order of magnitude as the ones of single REF52 cells. This contrasted with the expected strong cohesiveness of endothelial cells and indicated a lack of cell-cell contact formation. The latter was confirmed by a comparison of HUVECs, primary HBMVECs, and immortalized EA.hy926 cells fluorescently labeled for two marker proteins of intercellular junctions. This unveiled that both the previous cultivation duration and the cell type have a major impact on the development of intercellular junctions. In summary, the correlative FL FluidFM® represents a powerful novel approach, which enables a truly contemporaneous performance and, thus, has the potential to reveal new insights into the mechanobiological properties of cell adhesion.},
  language  = {en}
}