title: Direct Intracellular Delivery of Cell-Impermeable Probes of Protein Glycosylation by Using Nanostraws.
abstract: Bioorthogonal chemistry is an effective tool for elucidating metabolic pathways and measuring cellular activity, yet its use is currently limited by the difficulty of getting probes past the cell membrane and into the cytoplasm, especially if more complex probes are desired. Here we present a simple and minimally perturbative technique to deliver functional probes of glycosylation into cells by using a nanostructured "nanostraw" delivery system. Nanostraws provide direct intracellular access to cells through fluid conduits that remain small enough to minimize cell perturbation. First, we demonstrate that our platform can deliver an unmodified azidosugar, N-azidoacetylmannosamine, into cells with similar effectiveness to a chemical modification strategy (peracetylation). We then show that the nanostraw platform enables direct delivery of an azidosugar modified with a charged uridine diphosphate group (UDP) that prevents intracellular penetration, thereby bypassing multiple enzymatic processing steps. By effectively removing the requirement for cell permeability from the probe, the nanostraws expand the toolbox of bioorthogonal probes that can be used to study biological processes on a single, easy-to-use platform.
authors.affiliation: Department of Materials Science and Engineering, Stanford University, 476 Lomita Mall, Stanford, CA, 94305, USA.|Present address: Chemistry and Chemical Engineering Division, California Institute of Technology, 1200 E California Boulevard, Pasadena, CA, 91106, USA.
authors.forename: Alexander M
authors.identifier: 0000-0003-4877-4358
authors.initials: AM
authors.lastname: Xu
authors.affiliation: Department of Materials Science and Engineering, Stanford University, 476 Lomita Mall, Stanford, CA, 94305, USA.
authors.forename: Derek S
authors.initials: DS
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, CA, 94305, USA.
authors.forename: Peyton
authors.initials: P
authors.lastname: Shieh
authors.affiliation: Department of Materials Science and Engineering, Stanford University, 476 Lomita Mall, Stanford, CA, 94305, USA.
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Department of Materials Science and Engineering, Stanford University, 476 Lomita Mall, Stanford, CA, 94305, USA.
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Melosh
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D000818:Animals; D001386:Azides / Q000737:chemistry*; D016466:CHO Cells; D002232:Carbocyanines / Q000737:chemistry; D002463:Cell Membrane Permeability; D003412:Cricetulus; D016503:Drug Delivery Systems; D005456:Fluorescent Dyes / Q000737:chemistry; D006031:Glycosylation; D006595:Hexosamines / Q000737:chemistry*; D015335:Molecular Probes / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D011499:Protein Processing, Post-Translational; D012235:Rhodamines / Q000737:chemistry; D014536:Uridine Diphosphate N-Acetylgalactosamine / Q000031:analogs & derivatives* / Q000737:chemistry
chemical_list: D001386:Azides; D002232:Carbocyanines; D005456:Fluorescent Dyes; D006595:Hexosamines; D015335:Molecular Probes; C405953:N-azidoacetylmannosamine; D012235:Rhodamines; C000622611:UDP-N-azidoacetylgalactosamine; C089187:cyanine dye 3; C000622612:peracetylated N-azidoacetylmannosamine; D014536:Uridine Diphosphate N-Acetylgalactosamine; D000537:Aluminum Oxide
keywords: click chemistry; drug delivery; fluorescent probes; glycosylation; nanotubes