Dilute self-healing hydrogels of silk-collagen-like block copolypeptides at neutral pH

Biomacromolecules. 2014 Mar 10;15(3):699-706. doi: 10.1021/bm401682n. Epub 2014 Feb 7.

Abstract

We report on self-healing, pH-responsive hydrogels that are entirely protein-based. The protein is a denovo designed recombinant triblock polypeptide of 66 kg/mol consisting of a silk-like middle block (GAGAGAGH)48, flanked by two long collagen-inspired hydrophilic random coil side blocks. The pH-dependent charge on the histidines in the silk block controls folding and stacking of the silk block. At low pH the protein exists as monomers, but above pH 6 it readily self-assembles into long fibers. At higher concentrations the fibers form self-healing physical gels. Optimal gel strength and self-healing are found at a pH of around 7. The modulus of a 2 wt % gel at pH 7 is G' = 1700 Pa. Being protein-based, and amenable to further sequence engineering, we expect that these proteins are promising scaffold materials to be developed for a broad range of biomedical applications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Collagen / chemistry*
  • Humans
  • Hydrogels / chemistry*
  • Hydrogen-Ion Concentration
  • Hydrophobic and Hydrophilic Interactions
  • Macromolecular Substances
  • Peptides / chemistry*
  • Polymers / chemistry*
  • Rheology / methods

Substances

  • Hydrogels
  • Macromolecular Substances
  • Peptides
  • Polymers
  • Collagen