2. Academic Validation
  3. Properties of Parallel Tetramolecular G-Quadruplex Carrying N-Acetylgalactosamine as Potential Enhancer for Oligonucleotide Delivery to Hepatocytes

Properties of Parallel Tetramolecular G-Quadruplex Carrying N-Acetylgalactosamine as Potential Enhancer for Oligonucleotide Delivery to Hepatocytes

  • Molecules. 2022 Jun 20;27(12):3944. doi: 10.3390/molecules27123944.
Anna Clua 1 2,  Santiago Grijalvo 1 2,  Namrata Erande 3,  Swati Gupta 3,  Kristina Yucius 3,  Raimundo Gargallo 4,  Stefania Mazzini 5,  Muthiah Manoharan 3,  Ramon Eritja 1 2
Affiliations

Affiliations

  • 1 Institute for Advanced Chemistry of Catalonia (IQAC-CSIC), Jordi Girona 18-26, E-08034 Barcelona, Spain.
  • 2 Networking Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), E-08034 Barcelona, Spain.
  • 3 Alnylam Pharmaceuticals, 300 Third Street, Cambridge, MA 02142, USA.
  • 4 Department of Chemical Engineering and Analytical Chemistry, University of Barcelona, Martí i Franquès 1-11, E-08028 Barcelona, Spain.
  • 5 DEFENS-Dipartimento Di Scienze per Gli Alimenti, la Nutrizione e l'Ambiente, Università degli Studi di Milano, Via Celoria, 2, 20133 Milan, Italy.
PMID: 35745067 DOI: 10.3390/molecules27123944
Abstract

The development of oligonucleotide conjugates for in vivo targeting is one of the most exciting areas for oligonucleotide therapeutics. A major breakthrough in this field was the development of multifunctional GalNAc-oligonucleotides with high affinity to asialoglycoprotein receptors (ASGPR) that directed therapeutic Oligonucleotides to hepatocytes. In the present study, we explore the use of G-rich sequences functionalized with one unit of GalNAc at the 3'-end for the formation of tetrameric GalNAc nanostructures upon formation of a parallel G-quadruplex. These compounds are expected to facilitate the synthetic protocols by providing the multifunctionality needed for the binding to ASGPR. To this end, several G-rich Oligonucleotides carrying a TGGGGGGT sequence at the 3'-end functionalized with one molecule of N-acetylgalactosamine (GalNAc) were synthesized together with appropriate control sequences. The formation of a self-assembled parallel G-quadruplex was confirmed through various biophysical techniques such as circular dichroism, nuclear magnetic resonance, polyacrylamide electrophoresis and denaturation curves. Binding experiments to ASGPR show that the size and the relative position of the therapeutic cargo are critical for the binding of these nanostructures. The biological properties of the resulting parallel G-quadruplex were evaluated demonstrating the absence of the toxicity in cell lines. The internalization preferences of GalNAc-quadruplexes to hepatic cells were also demonstrated as well as the enhancement of the luciferase inhibition using the luciferase assay in HepG2 cell lines versus HeLa cells. All together, we demonstrate that tetramerization of G-rich oligonucleotide is a novel and simple route to obtain the beneficial effects of multivalent N-acetylgalactosamine functionalization.

Keywords

G-quadruplex; N-acetylgalactosamine; antisense; asialoglycoprotein receptor; gapmers; luciferase gene; oligonucleotide conjugates.

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