Specific DNA-binding molecules as new transfection vectors

• Applicant: Professor Michael Giese, Ph.D., since 8/2019
• Subject Area: Biological and Biomimetic Chemistry
• Term: from 2013 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 233924428

We could develop a new class of small peptide-based non-viral genetransfection vectors. their efficiency is comparable to the currentstandards scuh as Lipofecatmine or PEI, but they non-cytotoxic (incontrast to PEI e.g.). Important for these vectors is the use of ourGCP-group as a tailor-made anion binding site for specific DNArecognition. This also facilitates DNA condensation which is requiredfor cell uptake. As he GCP groups are also only weakly basic,endosomal escape using a proton sponge effect is also enhanced.Related compounds with the natural amino acids lysine or arginineinstead of our GCP group are inactive as transfection vectors. Duringthe first fundin period the main focus was on optimizing DNA-bindingand -condensation (e.g. by Variation of the amino acid sequence ofthe binding arms) as well as enhanciong endosomal escape (by usingthe proton sponge effect and the hydrophobization of the vectors).Questions such as the stability of the DNA in the cytosol or therelevance of DNA dissociation from the vector complexes or thenuclear import were not yet addressed. Also a specific targeting ofdifferent cell types or the use of our vectros in more complexnanocomposites together with other vector types such as lipids wasnot yet studied. Such questions will now be addressed during thesecond funding period. Besides more sophisticated mechanisticstudies using fluorophor labbeled vectors, we will try to improvetransfection efficiencies using two different strategies: enhancedintracellular complex dissociation by using redox labile vectors andspecific targeting using signal molecules for enhanced cell uptake andnuclear import. In a last more explorative project we will test ourligands in functionalized nanoparticles and liposomes as newtransport systems. We thus hope to not only enhance ourunderstanding of nonviral gene transfection in general but also to beable to develop highly efficient, nontoxic and universially applicablegene transfection vectors based on our GCP group.

• DFG Programme: Research Grants
• Ehemaliger Antragsteller: Professor Dr. Carsten Schmuck, until 8/2019 (†)