Sulfobetaines Meet Carboxybetaines: Modulation of Thermo- and Ion-Responsivity, Water Structure, Mechanical Properties, and Cell Adhesion

Langmuir. 2019 Feb 5;35(5):1391-1403. doi: 10.1021/acs.langmuir.8b01592. Epub 2018 Sep 6.

Abstract

A procedure for the preparation of copolymers bearing sulfobetaine and carboxybetaine methacrylic-based monomers by free-radical polymerization is described and discussed. A combination of monomers affects the upper critical solution temperature (UCST) in water and in the presence of a simple NaCl electrolyte while retaining the zwitterionic character. In addition, hydrogel samples were prepared and showed tunable water structure and mechanical properties. The total nonfreezable water content decreases with the amount of carboxybetaine segment in the hydrogel feed and the compression moduli were in a range of 0.7-1.6 MPa. Responses to external conditions such as temperature and ion strength were investigated and a potential application such as modulated thermal detection is proposed. The presence of the carboxylate group in the carboxybetaine segment enables a small fluorescence probe and peptide bearing RDG motif to be attached to polymer and hydrogel samples, respectively. The hydrogel samples functionalized with the RGD motif exhibit controlled cell adhesion. Such synthetic strategy based on combination of different zwitterionic segments offers a simple pathway for the development of zwitterionic materials with programmable properties.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3T3 Cells
  • Animals
  • Betaine / analogs & derivatives
  • Betaine / chemistry
  • Cell Adhesion / drug effects*
  • Hydrogels / chemical synthesis
  • Hydrogels / chemistry
  • Hydrogels / pharmacology
  • Hydrogen-Ion Concentration
  • Mice
  • Osmolar Concentration
  • Polymerization
  • Polymethacrylic Acids / chemical synthesis
  • Polymethacrylic Acids / chemistry
  • Polymethacrylic Acids / pharmacology*
  • Transition Temperature
  • Viscoelastic Substances / chemical synthesis
  • Viscoelastic Substances / chemistry
  • Viscoelastic Substances / pharmacology
  • Water / chemistry*

Substances

  • Hydrogels
  • Polymethacrylic Acids
  • Viscoelastic Substances
  • Water
  • Betaine
  • sulfobetaine