Unusual Salt Stability in Highly Charged Diblock Co-polypeptide Hydrogels

Andrew P. Nowak, Victor Breedveld, David J. Pine, Timothy J. Deming

Research output: Contribution to journalArticle

Abstract

The stability and properties of dilute solution hydrogels, synthesized by transition metal mediated polymerization of amino acid N-carboxyanhydrides (NCAs), have been studied in deionized (DI) water as well as various ionic media. These hydrogels are diblock amphiphilic copolymers of hydrophilic, charged segments of poly(L-lysine HBr) or poly(L-glutamic acid sodium salt), and helical, hydrophobic segments of poly(L-leucine). While many of these samples are able to form strong gels in deionized water at polymer concentrations as low as 0.25 wt %, stability in salt or buffer solutions was found to be only achieved at moderately higher polymer concentrations (∼3.0 wt %). We have adjusted relative copolymer compositions and molecular weights to optimize hydrogel strength and polymer solubility in salt concentrations up to 0.5 M NaCl, as well as in cell growth media and aqueous buffers of varying pH. These materials are unique since they do not collapse in high ionic strength media, even though gel formation is contingent upon the presence of highly charged polyelectrolyte segments. The remarkable properties of these hydrogels make them excellent candidates for use as scaffolds in biomedical applications, such as tissue regeneration.

Original languageEnglish (US)
Pages (from-to)15666-15670
Number of pages5
JournalJournal of the American Chemical Society
Volume125
Issue number50
DOIs
StatePublished - Dec 17 2003

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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