2005 journal article

Effect of beta-sheet crystals on the thermal and rheological behavior of protein-based hydrogels derived from gelatin and silk fibroin

MACROMOLECULAR BIOSCIENCE, 5(8), 702–709.

By: E. Gil n, R. Spontak n  & S. Hudson n

co-author countries: United States of America πŸ‡ΊπŸ‡Έ
author keywords: gelatin; helix-coil transition; hydrogels; polymer network; silk fibroin
MeSH headings : Animals; Bombyx / chemistry; Calorimetry, Differential Scanning; Fibroins / chemistry; Gelatin / chemistry; Hot Temperature; Hydrogels / chemistry; Insect Proteins / chemistry; Protein Structure, Secondary; Swine
Source: Web Of Science
Added: August 6, 2018

Novel protein-based hydrogels have been prepared by blending gelatin (G) with amorphous Bombyx mori silk fibroin (SF) and subsequently promoting the formation of beta-sheet crystals in SF upon exposure to methanol or methanol/water solutions. Differential scanning calorimetry of the resultant hydrogels confirms the presence and thermoreversibility of the G helix-coil transition between ambient and body temperature at high G concentrations. At low G concentrations, this transition is shifted to higher temperatures and becomes progressively less pronounced. Complementary dynamic rheological measurements reveal solid-liquid cross-over at the G helix-coil transition temperature typically between 30 and 36 degrees C in blends prior to the formation of beta-sheet crystals. Introducing the beta-sheet conformation in SF stabilizes the hydrogel network and extends the solid-like behavior of the hydrogels to elevated temperatures beyond body temperature with as little as 10 wt.-% SF. The temperature-dependent elastic modulus across the G helix-coil transition is reversible, indicating that the conformational change in G can be used in stabilized G/SF hydrogels to induce thermally triggered encapsulant release.