title: Synthesis and cellular uptake of fluorescently labeled multivalent hyaluronan disaccharide conjugates of oligonucleotide phosphorothioates.
abstract: Clustered hyaluronan disaccharides were studied as mediators of cellular delivery of antisense oligonucleotides through receptor-mediated endocytosis. For this purpose, a synthetic route for preparation of an appropriately protected hyaluronic acid dimer bearing an aldehyde tether (1) was devised. Up to three non-nucleosidic phosphoramidite building blocks (2), each bearing two phthaloyl protected aminooxy groups, were then inserted into the 3'-terminus of the desired phosphorothioate oligodeoxyribonucleotide, and 6-FAM phosphoramidite was introduced into the 5'-terminus. After completion of the chain assembly, the aldehyde-tethered sugar ligands were attached to the deprotected aminooxy functions by on-support oximation. Three fluorescein-labeled phosphorothioate oligonucleotide glycoconjugates (28-30) containing two, four, or six hyaluronan disaccharides were prepared. The influence of the hyaluronan moieties on the cellular uptake of the thioated oligonucleotides was tested in a cell line expressing the hyaluronan receptor CD44. Specific uptake was not detected with this combination of multiple hyaluronan disaccharides.
authors.affiliation: Department of Chemistry, University of Turku, FI-20014 Turku, Finland. Marika.Karskela@utu.fi
authors.forename: Marika
authors.initials: M
authors.lastname: Karskela
authors.forename: Pasi
authors.initials: P
authors.lastname: Virta
authors.forename: Melina
authors.initials: M
authors.lastname: Malinen
authors.forename: Arto
authors.initials: A
authors.lastname: Urtti
authors.forename: Harri
authors.initials: H
authors.lastname: Lönnberg
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D002460:Cell Line; D019281:Dimerization; D004705:Endocytosis; D005434:Flow Cytometry; D005456:Fluorescent Dyes / Q000737:chemistry*; D005786:Gene Expression Regulation; D006001:Glycoconjugates / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D006820:Hyaluronic Acid / Q000737:chemistry*; D008024:Ligands; D054735:Phosphorothioate Oligonucleotides / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D000447:Aldehydes; D005456:Fluorescent Dyes; D006001:Glycoconjugates; D018960:Hyaluronan Receptors; D008024:Ligands; D054735:Phosphorothioate Oligonucleotides; D006820:Hyaluronic Acid