A Fluorophore‐Labeled Lysine Dendrimer with an Oxo‐Anion‐Binding Motif for Tracking Gene Transfection

A transfection vector based on a peptide dendrimer (1) was developed and its ability for DNA binding and transport investigated. By attaching a fluorophore to the vector system (1*), several steps in the transfection process could be monitored directly. As DLS and AFM studies showed, the labeled vector1*condensed DNA into tightly packed aggregates able to enter eukaryotic cells. Co-localization experiments revealed that the ligand/plasmid complex is taken upviathe endosomal pathway followed by an endosomal escape or lysosomal degradation. Afterwards, the plasmid DNA seems to enter the nucleus due to a breakdown of the nuclear envelope during mitosis, as only cells that have recently undergone mitosis showed H2B-GFP expression.