Inhaltszusammenfassung

The use of nanomedicine has recently opened new perspectives in the field of drug delivery, while the comprehension on how nanocarriers interact with biological systems still remains to be a big challenge. Upon contact of the nanomaterial with a biological fluid like blood plasma, a ‘protein corona’ develops from the adsorption of proteins and other biomolecules on the nanocarrier surface. The adsorbed proteins determine the biological response and, therefore, understanding the processes invo...The use of nanomedicine has recently opened new perspectives in the field of drug delivery, while the comprehension on how nanocarriers interact with biological systems still remains to be a big challenge. Upon contact of the nanomaterial with a biological fluid like blood plasma, a ‘protein corona’ develops from the adsorption of proteins and other biomolecules on the nanocarrier surface. The adsorbed proteins determine the biological response and, therefore, understanding the processes involved in the protein corona formation is crucial to make nanomedicine reliable, successful and safe. Currently, the main focus in the protein corona analysis is the investigation of the ‘hard corona’, which describes the strongly adsorbed proteins usually separated via centrifugation. However, there are more aspects contributing to the protein corona, leading to a discrepancy between the in vitro and in vivo characterization. In the presented thesis, asymmetric flow field-flow fractionation (AF4) has been introduced as a new separation technique for the isolation of differently sized components like nanocarrier-protein complexes or plasma protein fractions. Combining this technique with subsequent analysis steps, new insights into the protein corona formed from human blood plasma have been highlighted for the first time. With the AF4, also loosely bound proteins contributing to the ‘soft corona’ on polystyrene nanoparticles could be preserved. The obtained corona could be compared with the hard corona after centrifugation in terms of size, composition and cellular uptake. The separation process was adopted to liposomes as potential drug carriers. The influence of hyperbranched polyglycerol as surface functionality on liposomes was investigated for its potential ‘stealth effect’, meaning a minimized unspecific protein adsorption and cell uptake. Furthermore, AF4 proved to be a valuable tool for the separation of plasma into smaller entities, enabling a more detailed data evaluation of the complex protein mixture. After removal of the silica nanoparticles including their protein corona, the protein residue of plasma was investigated. This way, a depletion of the most prominent protein of the protein corona could be identified, as well as a changed retention behavior of the supernatant. Additionally, considering the flow after intravenous injection of nanocarriers, a light scattering set-up was used to observe the influence of the blood flow on the protein corona formation. From the presented results, a broader knowledge of the various parameters influencing the protein corona was obtained, and new techniques were introduced for the analysis of the nanocarrier-protein interactions that can be related to realistic in vivo conditions.» weiterlesen» einklappen

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DDC Sachgruppe:
Chemie