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Lamellar biogels comprising fluid membranes with a newly synthesized class of polyethylene glycol-surfactants

Title data

Warriner, Heidi E. ; Davidson, Patrick ; Slack, Nelle L. ; Schellhorn, Mathias ; Eiselt, Petra ; Idziak, Stefan H. J. ; Schmidt, Hans-Werner ; Safinya, Cyrus R.:
Lamellar biogels comprising fluid membranes with a newly synthesized class of polyethylene glycol-surfactants.
In: The Journal of Chemical Physics. Vol. 107 (1997) Issue 9 . - pp. 3707-3722.
ISSN 0021-9606
DOI: https://doi.org/10.1063/1.474726

Abstract in another language

A series of four polymer-surfactant macromolecules, each consisting of a double-chain hydrophobic moiety attached onto a monofunctional polyethylene glycol (PEG) polymer chain, were synthesized in order to study their effect upon the fluid lamellar liquid crystalline (Lα) phase of the dimyristoylphosphatidylcholine/pentanol/water system. The main finding of this study is that the addition of these compounds induces a new lamellar gel, called Lα,g. We have determined the phase diagrams as a function of PEG-surfactant concentration, cPEG, and weight fraction water, ΦW. All phase diagrams are qualitatively similar and show the existence of the gel. Unlike more common polymer physical gels, this gel can be induced either by increasing cPEG or by adding water at constant cPEG. In particular, less polymer is required for gelation as water concentration increases. Moreover, the gel phase is attained at concentrations of PEG-surfactant far below that required for classical polymer gels and is stable at temperatures comparable to the lower critical solution temperature of free PEG-water mixtures. Small angle x-ray experiments demonstrate the lamellar structure of the gel phase, while wide angle x-ray scattering experiments prove that the structure is Lα, not Lβ′ (a common chain-ordered phase which is also a gel). The rheological behavior of the Lα,g phase demonstrates the existence of three dimensional elastic properties. Polarized light microscopy of Lα,g samples reveals that the Lα,g is induced by a proliferation of defect structures, including whispy lines, spherulitic defects, and a nematiclike Schlieren texture. We propose a model of topological defects created by the aggregation of PEG-surfactant into highly curved regions within the membranes. This model accounts for both the inverse relationship between ΦW and cPEG observed along the gel transition line and the scaling dependence of the interlayer spacing at the gel transition with the PEG molecular weight. These Lα hydrogels could serve as the matrix for membrane-anchored peptides, proteins or other drug molecules, creating a "bioactive gel" with mechanical stability deriving from the polymer-lipid minority component. © 1997 American Institute of Physics.

Further data

Item Type: Article in a journal
Refereed: Yes
Institutions of the University: Faculties
Faculties > Faculty of Biology, Chemistry and Earth Sciences
Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry
Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry > Chair Macromolecular Chemistry I
Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry > Chair Macromolecular Chemistry I > Chair Macromolecular Chemistry I - Univ.-Prof. Dr. Hans-Werner Schmidt
Profile Fields > Advanced Fields > Polymer and Colloid Science
Profile Fields > Advanced Fields > Advanced Materials
Research Institutions > Research Centres > Bayreuth Institute of Macromolecular Research - BIMF
Profile Fields
Profile Fields > Advanced Fields
Research Institutions
Research Institutions > Research Centres
Result of work at the UBT: Yes
DDC Subjects: 500 Science > 540 Chemistry
Date Deposited: 30 Apr 2015 06:32
Last Modified: 09 Mar 2016 11:19
URI: https://eref.uni-bayreuth.de/id/eprint/1555