Hochschulschrift:
Dissertation, Albert-Ludwigs-Universität Freiburg im Breisgau, f2016
Anmerkungen:
Beschreibung:
Zusammenfassung: For non-viral transfections, the large pool of polymer candidates offers many synthetic poly-cations. Among the synthetic poly-cations, linear polyethylenimine (LPEI) remains the most extensively explored for DNA complexation. LPEI polyplexes have been successfully used to deliver genetic material into many cell types both in vitro and in vivo. The efficacy of a polyplex is influenced by both, its ability to condense the genetic material and also uncouple from it within the cell. In this study, the impact of the introduction of an additional component in the form of a serum protein in the LPEI/DNA polyplex on transfection efficiency was investigated. Ternary polyplexes composed of circular DNA, bovine serum albumin and LPEI were obtained in two types, either through pre-complexation of albumin with circular DNA prior to polyplex formation with LPEI or addition of albumin after formation of the polyplex. In the first part of the thesis, the ternary polyplexes were characterized using microscopy and physico-chemical methods. The following section of the thesis describes the studies on transfection efficiency of the ternary polyplexes in several epithelial cell lines. In addition, the study was extended to endothelial cell lines to study the influence of albumin on transfection with polyplexes. Throughout this study, it was observed that the order of incorporation of albumin into polyplexes has a distinct effect on its uptake and transfection efficiency. The characterization and transfection results proposed that the obtained albumin-polyplexes were distinguishable from LPEI-polyplexes. As last part of the thesis, we concluded that albumin plays a role in both the translocation of the complex into the cell and its unpackaging as evidenced through co-localization and albumin depletion studies