Structure and gelation mechanism of tunable guanosine-based supramolecular hydrogels

Zheng Li, Lauren E. Buerkle, Maxwell R. Orseno, Kiril A. Streletzky, Soenke Seifert, Alexander M. Jamieson, Stuart J. Rowan

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

The mechanism of gelation of 50/50 w/w mixtures of guanosine (G) and 2′,3′,5′-tri-O-acetylguanosine (TAcG) in aqueous 0.354 M KCl was investigated using a combination of static light scattering (SLS), polarized and depolarized dynamic light scattering (VV and VH DLS), small-angle neutron and X-ray scattering (SANS and SAXS), and viscometric experiments. SLS and viscometry show a dramatic increase in apparent molecular weight and hydrodynamic volume at 0.2 wt % and 0.3 wt %, respectively, indicating the critical concentration for self-association of G/TAcG quartets into columnar assemblies lies below 0.2 wt %. Above this concentration, SANS and SAXS generate complementary information on the structure of the individual columnar stacks. VV and VH DLS results indicate bimodal correlation functions, whose properties suggest, respectively, translational and rotational diffusion of a bimodal distribution of particles. The fast mode appears to originate from fibrillar agglomerates of G/TAcG columnar quartet assemblies, while the slow mode comes from microgel domains. Guinier plot analysis of the SLS data probes the internal structure of the microgel domains. Collectively, the results suggest that sol and microgel phases coexist below the macroscopic gel point, and that the sol phase contains individual columnar stacks of G/TAcG quartets and fibrillar aggregates formed via lateral aggregation of these columnar assemblies. With increasing concentration, the DLS data indicate a progressive increase in the volume fraction of microgel domains, which ultimately leads to macroscopic gelation. Prior observation of a transient network contribution to the gel rheology at low temperature is attributed to the presence of individual columnar stacks within the gel network.

Original languageEnglish
Pages (from-to)10093-10101
Number of pages9
JournalLangmuir
Volume26
Issue number12
DOIs
Publication statusPublished - 2010 Jun 15
Externally publishedYes

Fingerprint

guanosines
Hydrogels
Guanosine
gelation
Gelation
Light scattering
light scattering
Gels
Polymethyl Methacrylate
assemblies
Sols
Light
gels
Rheology
Viscosity measurement
Neutrons
Dynamic light scattering
Hydrodynamics
X ray scattering
viscometry

ASJC Scopus subject areas

  • Electrochemistry
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Materials Science(all)
  • Spectroscopy
  • Medicine(all)

Cite this

Li, Z., Buerkle, L. E., Orseno, M. R., Streletzky, K. A., Seifert, S., Jamieson, A. M., & Rowan, S. J. (2010). Structure and gelation mechanism of tunable guanosine-based supramolecular hydrogels. Langmuir, 26(12), 10093-10101. https://doi.org/10.1021/la100211y

Structure and gelation mechanism of tunable guanosine-based supramolecular hydrogels. / Li, Zheng; Buerkle, Lauren E.; Orseno, Maxwell R.; Streletzky, Kiril A.; Seifert, Soenke; Jamieson, Alexander M.; Rowan, Stuart J.

In: Langmuir, Vol. 26, No. 12, 15.06.2010, p. 10093-10101.

Research output: Contribution to journalArticle

Li, Z, Buerkle, LE, Orseno, MR, Streletzky, KA, Seifert, S, Jamieson, AM & Rowan, SJ 2010, 'Structure and gelation mechanism of tunable guanosine-based supramolecular hydrogels', Langmuir, vol. 26, no. 12, pp. 10093-10101. https://doi.org/10.1021/la100211y
Li Z, Buerkle LE, Orseno MR, Streletzky KA, Seifert S, Jamieson AM et al. Structure and gelation mechanism of tunable guanosine-based supramolecular hydrogels. Langmuir. 2010 Jun 15;26(12):10093-10101. https://doi.org/10.1021/la100211y
Li, Zheng ; Buerkle, Lauren E. ; Orseno, Maxwell R. ; Streletzky, Kiril A. ; Seifert, Soenke ; Jamieson, Alexander M. ; Rowan, Stuart J. / Structure and gelation mechanism of tunable guanosine-based supramolecular hydrogels. In: Langmuir. 2010 ; Vol. 26, No. 12. pp. 10093-10101.
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