title: A G₄·K⁺ hydrogel stabilized by an anion.
abstract: Supramolecular hydrogels derived from natural products have promising applications in diagnostics, drug delivery, and tissue engineering. We studied the formation of a long-lived hydrogel made by mixing guanosine (G, 1) with 0.5 equiv of KB(OH)4. This ratio of borate anion to ligand is crucial for gelation as it links two molecules of 1, which facilitates cation-templated assembly of G4·K(+) quartets. The guanosine-borate (GB) hydrogel, which was characterized by cryogenic transmission electron microscopy and circular dichroism and (11)B magic-angle-spinning NMR spectroscopy, is stable in water that contains physiologically relevant concentrations of K(+). Furthermore, non-covalent interactions, such as electrostatics, π-stacking, and hydrogen bonding, enable the incorporation of a cationic dye and nucleosides into the GB hydrogel.
authors.affiliation: Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20742, United States.
authors.forename: Gretchen Marie
authors.initials: GM
authors.lastname: Peters
authors.forename: Luke P
authors.initials: LP
authors.lastname: Skala
authors.forename: Taylor N
authors.initials: TN
authors.lastname: Plank
authors.forename: Brooke J
authors.initials: BJ
authors.lastname: Hyman
authors.forename: G N
authors.initials: GN
authors.lastname: Manjunatha Reddy
authors.forename: Andrew
authors.initials: A
authors.lastname: Marsh
authors.forename: Steven P
authors.initials: SP
authors.lastname: Brown
authors.forename: Jeffery T
authors.initials: JT
authors.lastname: Davis
mesh_terms: D000838:Anions / Q000737:chemistry; D001881:Borates / Q000737:chemistry*; D006151:Guanosine / Q000737:chemistry*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D011188:Potassium / Q000737:chemistry*
chemical_list: D000838:Anions; D001881:Borates; D006151:Guanosine; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D011188:Potassium