Diffusion and Birefringence of Bioactive Dyes in a Supramolecular Guanosine Hydrogel

Abstract

Transparent self-standing supramolecular hydrogels were readily prepared by the potassium-ion-mediated self-organization of guanosine and 8-bromoguanosine whilst the individual components precipitated within a few hours. VT-NMR spectroscopy showed that bromoguanosine was a superior gelator compared to guanosine. XRD analysis showed that gel formation was caused by stacked G-quartets. AFM analysis revealed dendritic architectures of the nanofibers in the two-component hydrogel network. DSC profiles showed that the hybrid hydrogels underwent sol-gel transition at lower temperature than the pure guanosine and bromoguanosine hydrogels. Interestingly, bioactive dyes, such as rose bengal, rhodamine-6-G, and fluorescein, could be diffused and released in a controlled manner. UV/Vis absorption and fluorescence spectroscopy and CLSM were used to investigate the diffusion behavior of dyes in the hydrogel network. These dyes exhibited strong birefringence in the gel network (0.07-0.1) as a result of the anisotropic organization.

Self-assembly of guanosine and deoxy-guanosine into hydrogels: monovalent cation guided modulation of gelation, morphology and self-healing properties

“…However, researchers have succeeded in developing a few guanosine derivative based hydrogels with enhanced lifetime stability. [28][29][30][31][32][33][34][35][36][37] Lehn and coworkers reported guanosine-5 0 -hydrazide based hydrogelation in the presence of monovalent ions including Na + , K + and NH 4 + . 29,30 An acetylated guanosine derivative, 8-methoxy-2 0 ,3 0 ,5 0 -tri-O-acetylguanosine forms hydrogels in the presence of Na + and K + ions.…”

Environment‐Sensitive Probes Containing a 2,6‐Diethynylpyridine Motif for Fluorescence Turn‐On Detection and Induction of Nanoarchitectures of Human Telomeric Quadruplex

“…reported the interaction of ligands with G‐quadruplexes in a plasmid by using AFM analysis 16. In our previous study, we reported the creation of G‐quartet‐based supramolecular architectures, such as hydrogels17a and transmembrane ion channels 17b. In continuation of our work on development of fluorescent probes for the detection of G‐quadruplex,10 we herein present bis(phenylethynyl)pyridinecarboxamides (BPEPs 1 and 2 ) as environment‐sensitive probes for the fluorescent turn‐on detection of h‐TELO .…”

Self‐Assembly of a Guanosine Derivative To Form Nanostructures and Transmembrane Channels

“…[3] The G-quartet like assembly has been demonstrated to incorporate aromatic dyes and drug molecules;u seful for industrial and biomedicinal applications. [5] We herein report the selfassembling and ion passage properties of a8 -bromosubstituted lipophilic guanosine derivative G1. In our previous report, we have used ac ombinationo fg uanosine 1 and 8-bromog uano-sine 2 to prepares table hydrogels.…”

“…[2] In the presence of metal ions, guanosine derivatives self-assemble to form macrocyclic G-quartets, [1a] which are building block of biologically relevant four stranded DNA and RNA secondary structures. [1] It has been reported that 8-substitutedg uanosined erivatives form stable self-assembled structures [4,5] as C-8 modification causes the nucleobasetop referentially adopt the syn-conformation and enables Hoogsteen type H-bonding. [1] It has been reported that 8-substitutedg uanosined erivatives form stable self-assembled structures [4,5] as C-8 modification causes the nucleobasetop referentially adopt the syn-conformation and enables Hoogsteen type H-bonding.…”

“…[5,11] To gain insights into the binding property of the G1 assembled nano-construct, we studied the emissiona nd steady state anisotropy of ab ioactive dye Rose Bengal in the presence of G1.T he fluorescencei ntensity of Rose Bengal was significantly decreased suggesting its incorporationi nto the G1 nano-construct (Figure 5a). [5,11] To gain insights into the binding property of the G1 assembled nano-construct, we studied the emissiona nd steady state anisotropy of ab ioactive dye Rose Bengal in the presence of G1.T he fluorescencei ntensity of Rose Bengal was significantly decreased suggesting its incorporationi nto the G1 nano-construct (Figure 5a).…”