Chemical Evolution of Nanomaterials for RNA Delivery and Genome Editing

RNA drugs require targeted, efficient, and safe delivery. A bio-inspired chemical evolution strategy identified small sequence-defined lipopeptides with outstanding RNA transfer efficacy, easy available by simple (4-5 step) synthesis using natural or artificial amino acids, and lipo amino fatty acids (LAFs). LAF-peptides are dynamic in their response to endosomal pH, resulting superior endosomal escape. Refinement of carriers in sequence and topologies generated U-shape topologies with polar domain between LAF lipids, and Bundle topologies with the polar domain at the end. Bundle carriers transfect in full serum at very low mRNA dose (only ~2 nanoparticles/cell). Upon systemic administration of mRNA complexes, expression is found in the majority of organs of mice, with the highest levels in the spleen. Formulation of siRNA into LAF-LNPs results in in vivo gene silencing in liver endothelial cells or, upon coating with suitable ligands, gene silencing targeted into tumor endothelial cells. Carriers for CRISPER Cas9/sgRNA trigger genome editing in cell culture at ultra-low dose and upon i.v. application in skeletal muscle, heart muscle or brain of mice. Molecular mechanisms of carriers are enlightened by biophysical (LogD), ultrastructural (TEM, SAXS) characterization and MD calculations. Carrier topologies drastically differ in their interaction with lipid membranes, as revealed by SAXS in cholesterol bulk phases. U-shapes form standard lamellar phases, the more rigid dendritic Bundles fusogenic form inverted phases, with immediate impact on transfection mechanism and kinetics.

Prof. Ernst Wagner is Chair of Pharmaceutical Biotechnology, Department Pharmacy, LMU Munich (since 2001). He was Director Cancer Vaccines, Boehringer Ingelheim 1992-2001 (world-wide first polymer-based gene therapy in 1994), 1987-1995 Group Leader at IMP Vienna and Vienna University Biocenter, 1985-1987 postdoc at ETH Zurich, 1985 PhD (TU Vienna). He is Academician of European Academy of Sciences, Controlled Release Society (CRS) College of Fellows, Honorary Professor at U of Sichuan.

He authored ≥ 533 publications, with ≥ 56 700 citations, h-index 120 (GS)