Cationic carrier supported peptide-based nanosystems for tumor targeting

Benli-Hoppe, Teoman (2023): Cationic carrier supported peptide-based nanosystems for tumor targeting. Dissertation, LMU München: Fakultät für Chemie und Pharmazie

Abstract

The delivery of therapeutic materials, including small molecules, genes, and oligonucleotides, offers great opportunities for the treatment of many diseases like genetic disorders, neurodegenerative diseases, and various cancer types. Especially sequence-defined polycationic oligoaminoamids (OAAs), as a polymeric nanoplatform, are interesting candidates to deliver nucleic acids and other structures with a polyanionic surface like red CDs. OAAs not just enhance the nanoparticle properties of the formulation but also bring the benefit of enabling the integration of targeting domains and other surface modifications. This thesis displays the research of fine-tuned OAAs, optimized for their different cargos (pDNA, siRNA, CDs), modified targeting peptides, attached via a monodisperse polyethylene glycol (PEG) spacer via click chemistry for enabling direct targeting of several tumor cell lines. In the first part a highly advanced cationizable lipo-oligoaminoamide (lipo-OAA), 1214, was used to compact siRNA. The created polyplex then was postmodified with a retro-enantio peptide (reTfR) for TfR targeting. Improved gene silencing is demonstrated in TfR-expressing KB and DU145 cells. Analogous pDNA polyplexes are successfully used for receptor-mediated gene delivery in TfR-rich K562 cells and Neuro2a cells. Six lipo-OAAs differing in their lipidic domain and redox-sensitive attachment of lipid residues were tested to evaluate the impact of core polyplex stability on receptor-dependent gene transfer. The current study could show, that well stabilizing 1214 / reTfR-2 polyplexes were far better suitable for siRNA delivery than for pDNA delivery. The less stabilized NonOcA-OAA 1258 or 1285 / reTfR-2 was suitable for pDNA delivery into erythroleukemic K562 cells, and the ssbb-based bioreducible DecA- or NonOcA-OAAs 1284 or 1285 / reTfR-2 best suited for neuroblastoma cells. Concluding, the retro-enantio peptide reTfR presented clear TfR receptor targeting, displaying an interesting candidate for improved in vivo application, due to its additional stability against serum proteases. In the second part a 4-armed OAA library of 21 carrier structures to coat and entrap red CDs (rCDs) was synthesized and screened to evaluate the best performer 1696, which encapsulated rCDs in a superior way, displayed by particle size, distribution, and zeta. As a next step this perfectionated formulation was postmodified with several peptide ligands to test its efficacy on U87 cells. rCD-1696-L57 conjugates had a superior transfection efficacy compared to non-targeted rCD-1696 conjugates, addressing the targeting efficacy of the L57 peptide to the LRP1 receptor, creating a CD-based model for potential BBB targeting, with the far sight of finding therapeutic agents able to treat CNS related neurogenerative diseases or brain cancer like glioma.

• Dokumententyp: Dissertationen (Dissertation, LMU München)
• Keywords: gene silencing, gene transfer, nanoparticles, pDNA, siRNA, transferrin receptors, solid-phase-supported synthesis, peptide ligand targeting, carbondots
• Themengebiete: 500 Naturwissenschaften und Mathematik ; 500 Naturwissenschaften und Mathematik > 540 Chemie
• Fakultäten: Fakultät für Chemie und Pharmazie
• Sprache der Hochschulschrift: Englisch
• Datum der mündlichen Prüfung: 28. März 2023
• 1. Bericht­erstatter:in: Wagner, Ernst