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Disputation Pierre Volz-Rakebrand

16.07.2021 | 13:00
Thema der Dissertation:
Exploring interactions between biological matter and dendritic nanoparticles through the application of fluorescence lifetime probes
Abstract: The lack of information on interactions between nanoparticles and the plethora of biomolecules poses one of the greatest challenges for the clinical translation of nanomedicine. In order to shed some light on these interactions, this disputation talk presents the development and application of time-resolved fluorescence spectroscopy and imaging approaches for polymeric nanoparticle systems and apply them to diverse in-vitro and ex-vivo test systems. The fluorescence lifetime defines the characteristic decay time of the excited electronic state of a fluorescent probe. On the one hand, it can be considered a parameter independent of fluorophore concentration, fluorescence intensity, or detection efficiency. On the other hand, fluorescence lifetimes can be sensitive to certain parameters of the physicochemical environment of a fluorescent probe, such as temperature, pH, steric restrictions, viscosity, polarity, or molecular interactions. By applying fluorescence lifetime probes, the scope of fluorescence read-outs can be extended to monitor biological nanoparticle interactions. Here, a fluorescent molecular rotor probe is applied to investigate molecular interactions between a polymeric nanoparticle and biomolecules like the protein corona forming serum albumin. In a next step, this gained fluorescence lifetime sensitivity of the nanoparticleprobe-conjugate is expanded in a fluorescence lifetime imaging microscopy (FLIM) approach to living cells interacting with polymeric nanoparticles. Based on distinct changes in fluorescence lifetime parameters, unknown cellular targets were identified and interpreted. Finally, multiphoton excitation enables live-tissue FLIM tomography of the nanoparticle’s interactions in tissue. This shows significant differences in the interaction modes of the polymeric nanoparticle with tissue in healthy and diseased state.

Zeit & Ort

16.07.2021 | 13:00